CCT - Certified Cardiographic Technician Exam — Questions and Answers

Question 1: Which of the following lead groups provides the primary view of the inferior wall of the left ventricle?

II, III, aVF (Correct answer)
V1, V2
V3, V4
I, aVL, V5, V6

Correct answer: II, III, aVF

Leads II, III, and aVF are known as the inferior leads because they are oriented to view the electrical activity from the inferior surface (diaphragmatic surface) of the heart. V1-V2 view the septum, V3-V4 view the anterior wall, and I, aVL, V5-V6 view the lateral wall.

Question 2: A Certified Cardiographic Technician (CCT) is preparing a patient for a 12-lead ECG. The patient has a hairy chest. Which of the following is the most appropriate action to ensure good electrode contact and a clear tracing?

Place the electrodes on the patient's back instead of the chest.
Press the electrodes down firmly over the hair.
Apply extra conductive gel over the hair to improve the signal.
Shave or clip small areas of hair where the electrodes will be placed. (Correct answer)

Correct answer: Shave or clip small areas of hair where the electrodes will be placed.

Dense chest hair can interfere with the adhesion of ECG electrodes and the quality of the electrical signal. To ensure a clear and accurate tracing, small areas where the electrodes are to be placed should be clipped or shaved to allow for direct skin contact.

Question 3: The formula to determine cardiac output, often known as CO, Q, or Qc, is as follows:

SV - HR =CO
SV / HR = CO
SV x HR = CO (Correct answer)
SV + HR = CO

Correct answer: SV x HR = CO

Heart rate (HR) and stroke volume (SV), the amount of blood the heart expels with each beat, are combined to form carbon dioxide (CO).

Question 4: What does 'right axis deviation' (RAD) mean on an ECG, and what is its typical axis range?

The mean QRS axis is between -30 and -90 degrees
The mean QRS axis is between 0 and +90 degrees
The mean QRS axis is greater than -90 degrees
The mean QRS axis is greater than +90 degrees, indicating the electrical axis points toward the right ventricle (Correct answer)

Correct answer: The mean QRS axis is greater than +90 degrees, indicating the electrical axis points toward the right ventricle

Right axis deviation is defined as a mean QRS axis greater than +90 degrees (some criteria use +100 degrees). It indicates that the net electrical force of ventricular depolarization is directed toward the right side.

Question 5: Which electrode placement is used for the CM5 lead in Holter monitoring?

Positive electrode at manubrium, negative at V5
Positive electrode at right leg, negative at left leg
Positive electrode at V5 position, negative at manubrium (Correct answer)
Positive electrode at V1, negative at left arm

Correct answer: Positive electrode at V5 position, negative at manubrium

CM5 (Chest-Manubrium lead 5) places the positive electrode at the V5 position on the chest and the negative electrode at the manubrium, which is optimal for detecting ischemic ST changes.

Question 6: A 60-year-old male is scheduled for a maximal exercise stress test. Using the most common standard formula, what is his age-predicted maximum heart rate (MHR)?

180 bpm
150 bpm
170 bpm
160 bpm (Correct answer)

Correct answer: 160 bpm

The most widely used and simplest formula to estimate maximum heart rate is 220 minus the patient's age. For a 60-year-old patient, the calculation is 220 - 60 = 160 bpm.

Question 7: Beta-blockers (Class II antiarrhythmics) produce which primary ECG effect?

ST elevation
Prolonged PR interval and slowed heart rate (Correct answer)
Widened QRS
Shortened PR interval

Correct answer: Prolonged PR interval and slowed heart rate

Beta-blockers slow AV nodal conduction, prolonging the PR interval, and decrease the overall heart rate by reducing sympathetic drive.

Question 8: Dried or insufficient electrode gel is most likely to cause:

Complete loss of precordial signals
60 Hz AC artifact from capacitive coupling
Increased skin-electrode impedance and poor signal quality (Correct answer)
Somatic tremor artifact in all leads

Correct answer: Increased skin-electrode impedance and poor signal quality

Dried electrode gel increases skin-electrode impedance, leading to poor signal quality, increased artifact, and unreliable tracings.

Question 9: In fast-responding cardiac tissues, which step of the action potential involves rapid depolarization and bringing the resting cell to threshold?

phase 3
phase 2
phase 1
phase 0 (Correct answer)

Correct answer: phase 0

Rapid depolarization of the cell to threshold, which activates voltage-dependent sodium channels, constitutes phase 0.

Question 10: Before performing a transesophageal echocardiogram (TEE), the technician must verify that which of the following has been completed?

A 12-lead ECG has been performed within the last hour.
The patient's family members are present in the room.
The patient has been NPO (nothing by mouth) for at least 30 minutes.
A valid, signed informed consent form is in the patient's chart. (Correct answer)

Correct answer: A valid, signed informed consent form is in the patient's chart.

Informed consent is a legal and ethical requirement before any invasive or semi-invasive procedure. The CCT must ensure that the patient has been properly informed about the procedure, its risks, benefits, and alternatives, and has voluntarily signed a consent form.

Question 11: A patient calls the clinic stating that their Holter monitor is beeping intermittently. They have checked the battery, and it appears to be fine. Which of the following is the most likely cause?

The device is operating normally.
A serious arrhythmia has been detected.
The monitor's memory is full.
A poor or detached electrode connection. (Correct answer)

Correct answer: A poor or detached electrode connection.

Intermittent beeping from a Holter monitor, especially when the battery is not the issue, most commonly indicates a problem with the signal acquisition, such as a loose or completely detached electrode. This breaks the electrical circuit, and the device alerts the user to the faulty connection.

Question 12: Accelerated idioventricular rhythm (AIVR) differs from VT in what important way?

AIVR has a narrower QRS than VT
AIVR has a ventricular rate of 40-100 bpm (slower than VT's >100 bpm) and is generally benign, often seen in reperfusion after MI (Correct answer)
AIVR always requires immediate defibrillation
AIVR is faster than VT and more immediately life-threatening

Correct answer: AIVR has a ventricular rate of 40-100 bpm (slower than VT's >100 bpm) and is generally benign, often seen in reperfusion after MI

AIVR (rate 40-100 bpm) is a slow ventricular rhythm that does not reach the threshold for VT (>100 bpm). It is characteristically seen during successful reperfusion after MI (a reperfusion arrhythmia) and is generally hemodynamically well-tolerated.

Question 13: Atrial fibrillation (AFib) with a rapid ventricular response typically presents with a ventricular rate in which range?

100-170 bpm (can be higher), irregular rhythm with absent discrete P waves, replaced by fibrillatory f waves (Correct answer)
60-80 bpm with regular rhythm
40-60 bpm with regular P waves and long PR intervals
200-300 bpm with regular sawtooth waves

Correct answer: 100-170 bpm (can be higher), irregular rhythm with absent discrete P waves, replaced by fibrillatory f waves

Uncontrolled (untreated) AFib typically conducts to the ventricles at rates of 100-170 bpm or higher, producing the characteristic irregularly irregular rhythm without identifiable discrete P waves.

Question 14: During the Bruce protocol, a patient achieves 85% of their age-predicted maximum heart rate without symptoms or ECG changes. How is this test best interpreted?

The test is diagnostic — the patient achieved target heart rate without evidence of ischemia (Correct answer)
The test is positive for ischemia because of the high heart rate achieved
The test is non-diagnostic because the patient did not develop symptoms
The test should be repeated immediately at a higher workload

Correct answer: The test is diagnostic — the patient achieved target heart rate without evidence of ischemia

Achieving 85% or more of the age-predicted maximum heart rate (APMHR) without developing symptoms or significant ECG changes constitutes an adequate and negative stress test, providing diagnostic certainty.

Question 15: Ventricular fibrillation (VF) appears as which pattern on the ECG?

Absent electrical activity (flat line) on all leads
Sawtooth waves at 300 bpm with regular QRS complexes
Completely chaotic, irregular, undulating waveforms with no identifiable QRS complexes, P waves, or T waves at an indeterminate rate (Correct answer)
Regular wide QRS complexes at 150-250 bpm with uniform morphology

Correct answer: Completely chaotic, irregular, undulating waveforms with no identifiable QRS complexes, P waves, or T waves at an indeterminate rate

VF produces completely disorganized electrical activity with chaotic, irregular waveforms of varying amplitude and frequency, with no recognizable QRS complexes, P waves, or T waves — the heart is in electrical chaos and not pumping.

Question 16: What is pacemaker failure to capture?

The pacemaker fires (spike visible) but does not depolarize the myocardium (no QRS follows) (Correct answer)
The pacemaker fires too slowly, below the programmed rate
The pacemaker senses intrinsic beats correctly but does not pace
The pacemaker does not fire at all, producing no spikes

Correct answer: The pacemaker fires (spike visible) but does not depolarize the myocardium (no QRS follows)

Failure to capture occurs when a pacemaker spike is visible on the ECG but is not followed by a QRS complex (or P wave for atrial pacing), meaning the electrical stimulus failed to depolarize the myocardium.

Question 17: The sinoatrial (SA) node is located in which cardiac structure?

Interventricular septum
Left atrium, near the pulmonary veins
AV junction between the atria and ventricles
Right atrium, near the superior vena cava junction (Correct answer)

Correct answer: Right atrium, near the superior vena cava junction

The SA node is located in the posterior wall of the right atrium, near the junction with the superior vena cava, at the sulcus terminalis.

Question 18: Which of the following best describes the term 'paroxysmal supraventricular tachycardia' (PSVT)?

A synonym for atrial fibrillation
Any tachycardia with a rate over 100 bpm
A specific diagnosis of atrial flutter with 2:1 conduction
An umbrella term for sudden-onset, regular narrow-complex tachycardias originating above the ventricles, including AVNRT, AVRT, and atrial tachycardia (Correct answer)

Correct answer: An umbrella term for sudden-onset, regular narrow-complex tachycardias originating above the ventricles, including AVNRT, AVRT, and atrial tachycardia

PSVT is a general term for various tachyarrhythmias that originate above the bundle of His, begin and end abruptly (paroxysmal), and usually present as a regular narrow-complex tachycardia — most commonly AVNRT, AVRT (with accessory pathway), and atrial tachycardia.

Question 19: A technician observes a rhythm strip where pacemaker spikes appear at a fixed rate, including some that fall shortly after the patient's own native QRS complexes. This indicates that the pacemaker is not recognizing the patient's intrinsic beats. What is this malfunction called?

Oversensing
Undersensing (Correct answer)
Pacemaker-mediated tachycardia
Failure to capture

Correct answer: Undersensing

Undersensing is the pacemaker's inability to 'see' or detect the patient's intrinsic cardiac activity. Because it fails to sense the native beat, it fires inappropriately, leading to competitive pacing where pacemaker spikes can occur soon after a native QRS.

Question 20: What does 'METs' stand for in the context of exercise stress testing, and what MET level indicates a good functional capacity?

Maximum Exercise Tolerance Score; >5 METs is excellent
Metabolic Equivalents of Task; ≥10 METs indicates good functional capacity with a favorable prognosis (Correct answer)
Myocardial Exercise Testing Standard; >8 METs is poor
Metabolic Energy Transfer; ≥15 METs is average

Correct answer: Metabolic Equivalents of Task; ≥10 METs indicates good functional capacity with a favorable prognosis

METs (Metabolic Equivalents of Task) measure exercise intensity relative to resting metabolism (1 MET = 3.5 mL O2/kg/min). Achieving ≥10 METs during exercise testing indicates good functional capacity and is associated with a favorable cardiovascular prognosis.

Question 21: A CCT is preparing a patient for a treadmill stress test. To ensure a high-quality ECG tracing with minimal artifact, what is the most critical preparatory step?

Instructing the patient to grip the handrails tightly
Ensuring the room is slightly cool
Placing the limb leads on the distal extremities
Abrading the skin at electrode sites (Correct answer)

Correct answer: Abrading the skin at electrode sites

Proper skin preparation, which includes cleaning and abrading the stratum corneum, is crucial for reducing skin impedance. Lower impedance allows for a better electrical signal to reach the electrode, significantly minimizing motion and other artifacts that are common during exercise.

Question 22: What happens when Persantine (dipyridamole) is tested under Persantine-thallium stress?

It lowers blood pressure
It opens heart valves
It removes blockages in the heart
It stimulates the heart to work harder, the way it would during exercise (Correct answer)

Correct answer: It stimulates the heart to work harder, the way it would during exercise

Patients unable to exercise conventionally, as on a treadmill, can analyze blood flow to their hearts thanks to the use of persantine.

Question 23: For a 12-lead ECG, where are the limb electrodes placed to meet the standard AHA guidelines when the patient has a below-knee amputation on the right leg?

Place both leg electrodes on the left leg
Place the right leg electrode on the right thigh or the most distal right limb stump (Correct answer)
Omit the right leg electrode entirely and proceed with 11 leads
Place the right leg electrode on the right arm

Correct answer: Place the right leg electrode on the right thigh or the most distal right limb stump

When a standard electrode position is unavailable due to amputation, the electrode should be placed on the most distal available part of that limb (the stump or thigh). This is noted on the ECG for the interpreting physician.

Question 24: A patient receiving IV adenosine during an SVT episode would most likely show which transient ECG finding?

Complete AV block with a brief asystole pause (Correct answer)
ST elevation
Prolonged QT
Ventricular tachycardia

Correct answer: Complete AV block with a brief asystole pause

Adenosine transiently blocks AV conduction, causing a brief period of complete AV block or asystole that typically terminates SVT.

Question 25: Left axis deviation (LAD) on a 12-lead ECG is defined as the QRS axis falling between:

-30° and -90° (Correct answer)
+90° and +180°
0° and +90°
-90° and -180°

Correct answer: -30° and -90°

Left axis deviation is defined as a QRS axis more negative than -30°, with the range of -30° to -90° representing pathological LAD on a standard 12-lead ECG.

Question 26: Which of the following ECG findings is an artifact rather than a true cardiac finding?

A perfectly regular, high-frequency oscillation at 60 Hz (AC interference) superimposed on all leads (Correct answer)
ST elevation in leads II, III, and aVF
A prolonged QTc interval of 550 ms
P waves that are absent in all leads

Correct answer: A perfectly regular, high-frequency oscillation at 60 Hz (AC interference) superimposed on all leads

60 Hz AC interference is an artifact caused by electromagnetic interference from electrical power lines and devices, not a cardiac electrical event. It appears as a regular, fine oscillation superimposed uniformly on all leads.

Question 27: Which personal protective equipment (PPE) is required when performing an ECG on a patient under contact and droplet precautions?

No special PPE is needed for ECG as there is no exposure to blood
Gloves only are sufficient for contact precautions
Gown, gloves, and surgical mask at minimum; eye protection if splashing risk is present (Correct answer)
N95 respirator, gown, gloves, and face shield for all precaution levels

Correct answer: Gown, gloves, and surgical mask at minimum; eye protection if splashing risk is present

Contact precautions require a gown and gloves; droplet precautions add a surgical mask. Eye protection is added if there is a risk of secretion splashing. This PPE combination protects against contact and droplet transmission.

Question 28: Reciprocal ST changes seen in leads I and aVL during an inferior MI indicate:

Posterior extension of the MI
Normal variant
Anterior ischemia
Reciprocal depression confirming inferior STEMI and its territory (Correct answer)

Correct answer: Reciprocal depression confirming inferior STEMI and its territory

ST depression in I and aVL is the expected reciprocal (mirror image) change that confirms inferior STEMI in II, III, aVF, helping to rule out pericarditis or artifact.

Question 29: Which ECG finding is pathognomonic for Wolff-Parkinson-White (WPW) syndrome during sinus rhythm?

Sawtooth flutter waves with regular ventricular response
Right bundle branch block pattern with RSR' in V1
Long PR interval with normal QRS morphology
Short PR interval (< 0.12 sec) plus a delta wave (slurred QRS onset) plus wide QRS (Correct answer)

Correct answer: Short PR interval (< 0.12 sec) plus a delta wave (slurred QRS onset) plus wide QRS

The ECG triad of WPW syndrome during sinus rhythm is: short PR interval (<0.12 sec), delta wave (slurred initial QRS deflection from pre-excitation), and widened QRS complex — all resulting from early ventricular activation through the accessory pathway.

Question 30: A patient at rest has a heart rate of 70 beats per minute and a stroke volume of 60 mL per beat. What is the patient's cardiac output?

1.16 L/min
7.0 L/min
3.6 L/min
4.2 L/min (Correct answer)

Correct answer: 4.2 L/min

Cardiac Output (CO) is calculated by multiplying Heart Rate (HR) by Stroke Volume (SV). The formula is CO = HR × SV. In this case, CO = 70 beats/min × 60 mL/beat = 4200 mL/min. To convert this to liters per minute, divide by 1000, which equals 4.2 L/min.

Question 31: A CCT student incorrectly places the V1 and V2 electrodes two intercostal spaces higher than the standard location (i.e., in the 2nd intercostal space instead of the 4th). Which of the following ECG changes is a likely result of this misplacement?

Inversion of the QRS complex in all precordial leads
An exaggerated R wave in V1
A significant increase in the amplitude of the T wave in V6
A pattern that may mimic an anterior ST-elevation MI or incomplete RBBB (Correct answer)

Correct answer: A pattern that may mimic an anterior ST-elevation MI or incomplete RBBB

Placing the V1 and V2 electrodes too high is a common error that can create false positive findings. This placement can alter the P wave and QRS morphology, potentially creating a pattern that resembles an incomplete right bundle branch block (RBBB), septal infarction, or an anterior ST-elevation MI (STEMI).

Question 32: Which finding on a 12-lead ECG is most specific for an acute anterior STEMI caused by proximal LAD occlusion?

Delta waves in V1-V3
ST elevation in V1-V4 with reciprocal depression in II, III, aVF (Correct answer)
ST elevation in V1-V4 with new LBBB pattern
Peaked T waves only in V2

Correct answer: ST elevation in V1-V4 with reciprocal depression in II, III, aVF

Anterior STEMI from proximal LAD occlusion causes ST elevation in V1-V4 with reciprocal inferior ST depression in II, III, and aVF, indicating a large ischemic territory.

Question 33: Which ECG machine filter setting is designed specifically to reduce low-frequency baseline wander?

Notch filter (60 Hz)
High-pass filter (e.g., 0.5 Hz cutoff) (Correct answer)
Low-pass filter (e.g., 40 Hz cutoff)
Band-reject filter centered at 50 Hz

Correct answer: High-pass filter (e.g., 0.5 Hz cutoff)

A high-pass filter blocks signals below its cutoff frequency (such as 0.5 Hz), eliminating low-frequency baseline wander while allowing cardiac signals to pass.

Question 34: A patient develops sustained ventricular tachycardia during a stress test. What is the technician's first action?

Stop the exercise immediately and alert the supervising physician while keeping the patient monitored (Correct answer)
Have the patient perform a Valsalva maneuver to self-terminate the VT
Continue the test to collect more data about the arrhythmia
Administer IV lidocaine per standing orders immediately

Correct answer: Stop the exercise immediately and alert the supervising physician while keeping the patient monitored

Sustained VT is an absolute indication to stop exercise immediately. The supervising physician must be notified immediately while the patient is moved to a supine position and continuously monitored for deterioration to VF.

Question 35: A CCT performing a 12-lead ECG notes a regular wide-complex tachycardia at 180 bpm with AV dissociation. What is the most likely diagnosis?

Sinus tachycardia with bundle branch block
Atrial flutter with 2:1 block
Supraventricular tachycardia with aberrant conduction
Ventricular tachycardia (VT) (Correct answer)

Correct answer: Ventricular tachycardia (VT)

AV dissociation (P waves marching through at a different rate than QRS) in a wide-complex tachycardia is pathognomonic for ventricular tachycardia and should prompt immediate notification.

Question 36: What is the purpose of the recovery phase after a stress test?

To recalibrate the ECG machine
To re-establish electrode contact that was lost during exercise
To monitor for delayed ECG changes and hemodynamic recovery, and ensure patient safety (Correct answer)
To rest the patient before they leave

Correct answer: To monitor for delayed ECG changes and hemodynamic recovery, and ensure patient safety

The recovery phase is a critical monitoring period where delayed ST changes or arrhythmias may appear, and where hemodynamic parameters (heart rate, blood pressure) return to baseline, confirming the patient is stable to leave.

Question 37: Which type of Holter artifact is most commonly caused by poor electrode-skin contact?

60 Hz electrical interference appearing as thick baseline
Baseline wander and motion artifact with low-amplitude or flat-line segments (Correct answer)
Respiratory artifact causing uniform undulation of the baseline
Muscle tremor artifact producing rapid irregular oscillations

Correct answer: Baseline wander and motion artifact with low-amplitude or flat-line segments

Poor electrode-skin contact causes high impedance at the electrode site, which results in baseline wander, loss of signal (flat line segments), and motion artifact as even minor movement breaks the electrical connection.

Question 38: A patient develops 3 mm of horizontal ST depression in lead V5 at peak exercise. What does this finding indicate?

A normal physiologic response to exercise
A positive stress test result suggesting myocardial ischemia (Correct answer)
Pericarditis unmasked by exercise
Artifact caused by lead movement during exercise

Correct answer: A positive stress test result suggesting myocardial ischemia

Horizontal or downsloping ST depression of 1 mm or more (measured 60-80 ms after the J point) is the diagnostic criterion for a positive stress test indicating myocardial ischemia. 3 mm is a strongly positive finding.

Question 39: In Einthoven's triangle, which statement correctly describes the relationship between leads I, II, and III?

Lead II = Lead I + Lead III (Einthoven's Law) (Correct answer)
All three leads are independent with no mathematical relationship
Lead I = Lead II + Lead III
Lead III = Lead I + Lead II

Correct answer: Lead II = Lead I + Lead III (Einthoven's Law)

Einthoven's Law states that at any given moment, the voltage in Lead II equals the sum of Lead I and Lead III (II = I + III). This mathematical relationship is the basis of the bipolar limb lead system.

Question 40: When is it appropriate to use the 'half-standardization' (5 mm/mV) setting on an ECG machine?

When QRS voltage is very low and complexes are hard to see
When the patient has a slow heart rate requiring larger waveforms
When QRS complexes are so tall that they overlap adjacent leads, making interpretation impossible at standard gain (Correct answer)
In all pediatric patients as a standard practice

Correct answer: When QRS complexes are so tall that they overlap adjacent leads, making interpretation impossible at standard gain

Half-standardization (reducing gain to 5 mm/mV instead of 10 mm/mV) is used when QRS or T wave amplitudes are so large at standard gain that complexes overflow into adjacent channels, overlapping and making the tracing uninterpretable.

Question 41: A patient's ECG shows a regular rhythm with a constant PR interval on all conducted beats. Suddenly, a P wave appears that is not followed by a QRS complex. This occurs unpredictably. This finding is most consistent with:

Sinus Arrest
Mobitz II Second-Degree AV Block (Correct answer)
Third-Degree AV Block
Mobitz I Second-Degree AV Block

Correct answer: Mobitz II Second-Degree AV Block

Mobitz II Second-Degree AV Block is characterized by a constant PR interval in the conducted beats and intermittent, unpredictable non-conducted P waves (dropped QRS complexes). This type of block is considered more dangerous than Mobitz I because it can suddenly progress to complete heart block.

Question 42: In third-degree (complete) AV block, what is the key ECG finding that distinguishes it from other forms of AV block?

Non-conducted P waves occur after every 2 conducted P waves (3:2 block)
PR intervals are progressively lengthening with dropped beats
Complete AV dissociation: P waves and QRS complexes are completely independent with no relationship between them; both have their own regular, independent rates (Correct answer)
P waves occur at the same rate as QRS complexes but with very long fixed PR intervals

Correct answer: Complete AV dissociation: P waves and QRS complexes are completely independent with no relationship between them; both have their own regular, independent rates

Third-degree AV block shows complete dissociation between atrial and ventricular activity — P waves march through at the sinus rate while QRS complexes occur at a slower, independent escape rate with no fixed relationship between P waves and QRS complexes.

Question 43: True posterior MI is best confirmed on a 12-lead ECG by which finding in the standard leads?

Q waves in II, III, aVF
Tall broad R waves and ST depression in V1-V2 (mirror of posterior STEMI) (Correct answer)
Inverted P waves in V1
ST elevation in V1-V4

Correct answer: Tall broad R waves and ST depression in V1-V2 (mirror of posterior STEMI)

Posterior MI appears as a mirror image in V1-V2: tall, broad R waves (posterior Q equivalents) and ST depression (reciprocal of posterior ST elevation), confirmed with posterior leads V7-V9.

Question 44: Which chambers of the heart are separated by the interatrial septum?

Left atrium and left ventricle
Right ventricle and left ventricle
Right atrium and left atrium (Correct answer)
Right atrium and right ventricle

Correct answer: Right atrium and left atrium

The interatrial septum is the wall that separates the two atria. It contains the fossa ovalis, a remnant of the foramen ovale from fetal circulation.

Question 45: A pacemaker-dependent patient's ECG shows no pacing spikes and no intrinsic rhythm. What is the most urgent concern?

The patient is in a safe junctional escape rhythm
The pacemaker is in sleep mode
The ECG machine is not recording correctly
Complete pacemaker failure (failure to output) in a patient who has no escape rhythm, which is an immediately life-threatening emergency (Correct answer)

Correct answer: Complete pacemaker failure (failure to output) in a patient who has no escape rhythm, which is an immediately life-threatening emergency

Failure to output (no spikes despite no intrinsic rhythm) in a pacemaker-dependent patient is a cardiac emergency — without any electrical activity, the patient has no cardiac output and will rapidly deteriorate.

Question 46: A CCT is preparing a patient for a resting 12-lead ECG. The patient has a hairy chest. Which of the following is the most appropriate action for the technician to take?

Apply extra gel to the electrodes to ensure contact.
Shave the hair at the specific electrode placement sites with patient consent. (Correct answer)
Proceed with the ECG without any special preparation.
Place the electrodes on the patient's back instead.

Correct answer: Shave the hair at the specific electrode placement sites with patient consent.

To ensure good electrode-to-skin contact for a high-quality ECG tracing, any hair at the site of electrode placement should be removed. Shaving is the standard procedure, but it requires the patient's permission before proceeding.

Question 47: What does a 'Duke Treadmill Score' of +5 or greater indicate?

Intermediate risk requiring additional imaging
Low risk — annual mortality of less than 1% per year, suggesting the patient has a good prognosis (Correct answer)
High risk — annual mortality greater than 5% per year, requiring urgent intervention
The test was non-diagnostic and should be repeated

Correct answer: Low risk — annual mortality of less than 1% per year, suggesting the patient has a good prognosis

Duke Treadmill Score ≥ +5 indicates low risk with an estimated annual mortality of less than 1%, indicating a good prognosis. The score incorporates exercise time, ST deviation, and angina.

Question 48: Which ECG finding is characteristic of hypercalcemia?

Shortened QT interval (Correct answer)
Prolonged QT interval
Peaked T waves
Widened QRS

Correct answer: Shortened QT interval

Elevated calcium shortens the ST segment and therefore the QT interval, because calcium affects plateau-phase duration of the action potential.

Question 49: Which of the following frequently reduces the utility of Holter monitoring as a diagnostic tool?

Lack of continuous monitoring
Small capacity of recording devices
Patient noncompliance with keeping track of events (Correct answer)
Transmission of data depends on patient participation

Correct answer: Patient noncompliance with keeping track of events

The diagnostic utility of Holter monitoring is severely constrained by patient noncompliance with using event markers and keeping a diary of their symptoms. In order to correlate occurrences with the data gathered, it is crucial for patients to note and document their symptoms. A form of continuous monitoring known as holter monitoring has advantages such as the ability to transmit data without the involvement of the patient and the vast storage capacity of the recording devices.

Question 50: A patient who is undergoing an exercise stress test is instructed to:

physical appearance
Heart rate
all of the above (Correct answer)
Oxygen level

Correct answer: all of the above

The patient should keep an eye on his or her heart rate, oxygen level, and physical appearance throughout the exercise stress test.

Question 51: A 78-year-old sedentary female is referred for a symptom-limited exercise stress test. Which of the following treadmill protocols is most appropriate for this patient?

Astrand-Ryhming Protocol
Pharmacologic (Dobutamine) Protocol
Standard Bruce Protocol
Modified Bruce Protocol (Correct answer)

Correct answer: Modified Bruce Protocol

The Modified Bruce Protocol starts at a lower workload (slower speed and less incline) and has smaller increments between stages compared to the Standard Bruce Protocol. This makes it more suitable for elderly, deconditioned, or post-myocardial infarction patients who may not tolerate the more demanding initial stages of the standard protocol.

Question 52: ST elevation in leads V7, V8, and V9 (posterior leads) with reciprocal changes in V1-V2 confirms which diagnosis?

Pericarditis
Posterior STEMI (Correct answer)
Right ventricular STEMI
Anterior STEMI

Correct answer: Posterior STEMI

Posterior leads V7-V9 directly capture the posterior wall; ST elevation there with reciprocal depression in V1-V2 confirms true posterior STEMI, typically from circumflex artery occlusion.

Question 53: On the ECG, a junctional escape rhythm typically presents with which rate and P wave pattern?

Rate 100-150 bpm with absent P waves
Rate 20-40 bpm with wide QRS and inverted T waves
Rate 60-100 bpm with normal upright P waves and normal PR interval
Rate 40-60 bpm; P waves absent, inverted (retrograde) before or after QRS, or hidden within the QRS, with narrow QRS morphology (Correct answer)

Correct answer: Rate 40-60 bpm; P waves absent, inverted (retrograde) before or after QRS, or hidden within the QRS, with narrow QRS morphology

The AV junction (His bundle area) has an intrinsic escape rate of 40-60 bpm. Junctional beats conduct to the ventricles normally via the His-Purkinje system (narrow QRS), but P waves are absent or retrograde (inverted in II, III, aVF).

Question 54: Which kind of heart block can be noticed in the electrocardiogram (ECG) strip below?

Third-degree heart block
First-degree heart block
Second-degree heart block, type 2
Second-degree heart block, type 1 (Correct answer)

Correct answer: Second-degree heart block, type 1

A first-degree heart block occurs when the PR interval is longer than 0.2 seconds, but the PR interval typically remains constant and the QRS is not dropped. The pictured ECG is a second-degree heart block, type 1. This rhythm is also known as Mobitz I or Wenckebach. With this heart block, the PR interval gets longer with each beat until eventually a P wave occurs, but a QRS does not follow (a beat is skipped). After the skipped beat, the pattern starts over. This rhythm lacks the rising PR interval seen in the Mobitz I block and has a fairly constant ratio of P waves to QRS complexes. The atria and ventricles beat independently during a third-degree heart block, which is also known as a complete heart block.

Question 55: Calcium channel blockers (Class IV antiarrhythmics) such as verapamil primarily affect which interval on the ECG?

QT interval (prolongation)
QRS duration (widening)
PR interval (prolongation) (Correct answer)
RR interval shortening

Correct answer: PR interval (prolongation)

Verapamil and diltiazem slow AV nodal conduction by blocking L-type calcium channels, which prolongs the PR interval.

Question 56: Which of the following ECG findings is most characteristic of a ventricular-paced rhythm originating from a lead in the right ventricle?

A pacing spike followed by a P wave
Pacing spikes that occur randomly without relation to the QRS complex
A pacing spike followed by a narrow QRS complex (<0.12s)
A pacing spike followed by a wide QRS complex with a Left Bundle Branch Block (LBBB) morphology (Correct answer)

Correct answer: A pacing spike followed by a wide QRS complex with a Left Bundle Branch Block (LBBB) morphology

When the right ventricle is paced, the depolarization spreads slowly and abnormally to the left ventricle, bypassing the normal conduction pathway. This results in a wide QRS complex (>0.12s) that typically has a Left Bundle Branch Block (LBBB) appearance.

Question 57: A procedure that doesn't require entering the body cavity or puncturing or cutting the skin is:

physical therapy
arthroscopy
non-invasive (Correct answer)
invasive

Correct answer: non-invasive

Non-invasive procedures are diagnostic approaches that don't require skin punctures, incisions, or the insertion of foreign objects or materials into the body.

Question 58: A technician notices the QRS complex is predominantly positive in lead aVR on a routine ECG. This finding most likely indicates:

Normal variant in elderly patients
Right ventricular hypertrophy
Right arm and left arm lead reversal artifact (Correct answer)
Anterior myocardial infarction

Correct answer: Right arm and left arm lead reversal artifact

A predominantly positive QRS in aVR, which is always normally negative, is a classic indicator of right arm/left arm lead reversal.

Question 59: On a 12-lead ECG, a Brugada pattern is most commonly seen in which lead grouping?

Inferior leads II, III, aVF
Lateral leads I, aVL, V5-V6
Right precordial leads V1-V2 (Correct answer)
All 12 leads simultaneously

Correct answer: Right precordial leads V1-V2

Brugada pattern (coved-type ST elevation with RBBB morphology) is characteristically seen in the right precordial leads V1 and V2, reflecting right ventricular outflow tract abnormality.

Question 60: What is the normal R-wave progression across the precordial leads (V1 through V6)?

R wave decreases progressively from V1 through V6
R wave amplitude progressively increases from V1 to V5/V6, with transition (equal R and S) typically at V3 or V4 (Correct answer)
R wave is absent in V1-V3 and present only in V4-V6
R wave amplitude is equal in all precordial leads

Correct answer: R wave amplitude progressively increases from V1 to V5/V6, with transition (equal R and S) typically at V3 or V4

Normal R-wave progression shows a small r in V1 that gradually grows in amplitude through V2, V3, V4, and peaks at V5 or V6, with the R/S ratio transitioning from negative (S>R) to positive (R>S) typically at V3 or V4.

Question 61: Which symptom reported by a patient during stress testing is considered an anginal equivalent that should prompt test termination?

Mild shortness of breath that resolves with slightly reduced workload
Jaw or left arm discomfort concurrent with ischemic ECG changes (Correct answer)
Sweating at peak exercise without symptoms
Bilateral leg fatigue without other symptoms

Correct answer: Jaw or left arm discomfort concurrent with ischemic ECG changes

Jaw pain and left arm discomfort are classic anginal equivalents — manifestations of myocardial ischemia that do not present as typical chest pain. When these occur alongside ischemic ECG changes, the test should be stopped.

Question 62: What does the standard acquisition time for a 12-lead resting ECG represent — how many seconds of each lead are typically recorded in a standard 12-channel simultaneous acquisition?

30 seconds for limb leads and 10 seconds for precordial leads
Only 1 second per lead is sufficient
Typically 10 seconds of simultaneous recording across all 12 leads, providing approximately 2.5 seconds per grouping in some formats (Correct answer)
5 minutes of continuous recording for a standard resting ECG

Correct answer: Typically 10 seconds of simultaneous recording across all 12 leads, providing approximately 2.5 seconds per grouping in some formats

A standard 12-lead ECG records all 12 leads simultaneously for approximately 10 seconds, providing enough cardiac cycles for reliable rhythm analysis and interval measurement at 25 mm/second paper speed.

Question 63: A left bundle branch block (LBBB) on a 12-lead ECG is characterized by which set of findings?

Broad notched R in V1 and deep S in I
Short PR interval and delta wave
Broad notched R in I, aVL, V5-V6 and deep QS or rS in V1, QRS ≥120 ms (Correct answer)
S1Q3T3 pattern

Correct answer: Broad notched R in I, aVL, V5-V6 and deep QS or rS in V1, QRS ≥120 ms

LBBB features include a wide QRS (≥120 ms), broad monophasic R waves in lateral leads (I, aVL, V5-V6), and a deep QS or rS pattern in V1 due to abnormal left ventricular activation.

Question 64: A patient presents with a regular narrow-complex tachycardia at 180 bpm. P waves are inverted in leads II, III, aVF and appear just before each QRS with a very short RP interval. What is the most likely diagnosis?

Sinus tachycardia with a prolonged PR interval
AV nodal reentrant tachycardia (AVNRT) or junctional tachycardia with short VA conduction (Correct answer)
Accelerated junctional rhythm
Ventricular tachycardia with retrograde conduction

Correct answer: AV nodal reentrant tachycardia (AVNRT) or junctional tachycardia with short VA conduction

A regular narrow-complex tachycardia at ~180 bpm with retrograde P waves (inverted in inferior leads) immediately before the QRS (very short RP interval, typically < 70 ms) is classic for the slow-fast form of AVNRT.

Question 65: When calculating the height or depth of a wave from the baseline on an ECG, what is being measured?

Resistance
Voltage (Correct answer)
Power
Current

Correct answer: Voltage

Voltage is assessed by the amplitude of waves as seen from the baseline. Voltage, sometimes referred to as electrical potential difference, allows us to see how the heart repolarizes and depolarizes. These distances are calculated in millimeters.

Question 66: Which lead is considered the best single-lead view for detecting atrial activity and identifying P-wave morphology?

V5
V1 (Correct answer)
aVR
I

Correct answer: V1

Lead V1 sits directly over the right atrium and provides the clearest biphasic P wave, making it ideal for identifying atrial activity, flutter waves, and P-wave morphology.

Question 67: What ECG pattern is characteristic of type I (Wenckebach) second-degree AV block?

Progressively lengthening PR intervals culminating in a non-conducted P wave (dropped QRS), then the cycle resets (Correct answer)
Alternating conducted and non-conducted P waves with a fixed PR interval in conducted beats
Fixed PR interval with random non-conducted P waves
Complete AV dissociation with regular P waves and independent QRS complexes

Correct answer: Progressively lengthening PR intervals culminating in a non-conducted P wave (dropped QRS), then the cycle resets

Mobitz type I (Wenckebach) second-degree AV block shows progressive PR interval lengthening with each beat until one P wave fails to conduct (dropped QRS), then the cycle repeats — the classic 'footprints in the sand' pattern.

Question 68: What is the key ECG difference between a premature atrial contraction (PAC) with aberrant conduction and a premature ventricular contraction (PVC)?

A PAC always shows LBBB morphology; a PVC shows RBBB morphology
A PAC with aberrancy has a preceding (often abnormal) P wave and typically shows RBBB morphology; a PVC has no preceding P wave and has a different QRS morphology with a full compensatory pause (Correct answer)
A PVC has a shorter coupling interval than a PAC with aberrancy
Both have identical QRS morphology and can only be distinguished by clinical history

Correct answer: A PAC with aberrancy has a preceding (often abnormal) P wave and typically shows RBBB morphology; a PVC has no preceding P wave and has a different QRS morphology with a full compensatory pause

The presence of an abnormal P wave before the wide QRS (or a 'no P wave' for PVCs) and the morphology pattern (PAC with aberrancy is usually RBBB; PVCs vary) are the key distinguishing features.

Question 69: When interpreting a wide-complex tachycardia, which ECG finding most strongly supports a diagnosis of ventricular tachycardia rather than supraventricular tachycardia with aberrant conduction?

Axis within the normal range (-30 to +90 degrees)
RSR' pattern in V1
AV dissociation (P waves and QRS complexes are independent with P rate slower than QRS rate) (Correct answer)
QRS duration of exactly 0.12 seconds

Correct answer: AV dissociation (P waves and QRS complexes are independent with P rate slower than QRS rate)

AV dissociation — seeing independent P waves firing at a slower rate than the wide QRS complexes — is the most specific ECG finding for VT. It proves that the impulse originates in the ventricles, independent of atrial activity.

Question 70: ST elevation in leads V1-V4 combined with a new right bundle branch block most strongly suggests:

Anterior MI with septal involvement (Correct answer)
Inferior MI
Posterior MI
Pericarditis

Correct answer: Anterior MI with septal involvement

ST elevation in V1-V4 reflects anterior wall STEMI, and a new RBBB can indicate septal involvement, often due to LAD artery occlusion.

Question 71: Torsades de Pointes (TdP) is a specific form of polymorphic VT associated with which underlying ECG abnormality?

Right bundle branch block
Short QT interval
Prolonged QT interval (congenital or acquired) (Correct answer)
Pre-excitation (WPW pattern)

Correct answer: Prolonged QT interval (congenital or acquired)

Torsades de Pointes is triggered by early afterdepolarizations in the setting of a prolonged QT interval, and is characterized by the twisting of the QRS polarity around the baseline, resembling 'twisting of the points.'

Question 72: What is the standard, most common recording duration for a traditional Holter monitor test?

24-48 hours (Correct answer)
30 days
4-8 hours
7 days

Correct answer: 24-48 hours

The standard and most frequently prescribed duration for Holter monitoring is 24 to 48 hours. This timeframe provides a comprehensive overview of the heart's electrical activity during a typical cycle of daily activities and sleep. Longer monitoring periods usually involve different devices like event monitors or loop recorders.

Question 73: When analyzing an ECG for Premature Ventricular Contractions (PVCs), which characteristic is typically observed?

A narrow QRS complex (<0.12s) that is premature
A P wave preceding every premature QRS complex
A wide, bizarre QRS complex followed by a full compensatory pause (Correct answer)
A shortening of the R-R interval following the premature beat

Correct answer: A wide, bizarre QRS complex followed by a full compensatory pause

PVCs originate from an ectopic focus in the ventricles. This results in a premature, wide (≥0.12s), and abnormally shaped QRS complex because the impulse spreads through the myocardium instead of the rapid conduction pathway. It is typically followed by a compensatory pause, as the sinoatrial node's rhythm is not interrupted.

Question 74: Which characteristic best distinguishes 60 Hz AC interference from somatic tremor artifact?

Somatic tremor produces a perfectly regular pattern
AC interference is irregular and variable in amplitude
AC interference appears as uniform, regular oscillations at 60 cycles per second (Correct answer)
AC interference only affects precordial leads

Correct answer: AC interference appears as uniform, regular oscillations at 60 cycles per second

AC interference appears as perfectly regular, uniform oscillations at exactly 60 Hz, distinguishing it from the irregular, variable pattern of somatic tremor.

Question 75: A patient's ECG shows two distinct pacing spikes. The first spike is followed by a P wave, and after a short, fixed delay, a second spike appears, followed by a wide QRS complex. This pattern is consistent with which pacing mode?

Atrial pacing (AAI)
Ventricular pacing (VVI)
Biventricular pacing (CRT)
Dual-chamber AV sequential pacing (DDD) (Correct answer)

Correct answer: Dual-chamber AV sequential pacing (DDD)

This describes AV sequential pacing, a function of a dual-chamber pacemaker. The first spike captures the atrium, and the second spike captures the ventricle after a programmed AV delay, mimicking the natural sequence of cardiac contraction.

Question 76: A patient's rhythm strip displays a heart rate of 80 bpm. The technician notes that there are at least four different P wave morphologies, the R-R interval is irregular, and the PR interval varies. What is this rhythm?

Atrial Fibrillation
Sinus Arrhythmia with frequent PACs
Wandering Atrial Pacemaker (Correct answer)
Atrial Flutter

Correct answer: Wandering Atrial Pacemaker

Wandering Atrial Pacemaker (WAP) is defined by having at least three different P wave morphologies, an irregular rhythm, and a heart rate less than 100 bpm. [1, 11, 15] This indicates that the pacemaker site is shifting between various locations within the atria. If the rate were over 100 bpm, it would be Multifocal Atrial Tachycardia. [11, 15, 32]

Question 77: Which of the following statements best describes the role of the right leg (RL) electrode in a standard 12-lead ECG?

The RL electrode is optional and can be omitted without affecting any lead
The RL electrode serves as an electrical reference/ground that drives the common-mode rejection system, improving signal quality, and does not contribute to any of the 12 standard leads (Correct answer)
The RL electrode is the positive terminal for lead III
The RL electrode creates the augmented lead aVF

Correct answer: The RL electrode serves as an electrical reference/ground that drives the common-mode rejection system, improving signal quality, and does not contribute to any of the 12 standard leads

The right leg electrode serves as a driven ground reference that helps the ECG amplifier reject common-mode interference (like AC noise), improving signal quality. It does not directly contribute to any of the 12 standard ECG leads.

Question 78: Which of the following findings is considered an absolute indication to terminate an exercise stress test immediately?

Patient request to stop (Correct answer)
Downsloping ST-segment depression of 2 mm
Frequent premature ventricular contractions (PVCs)
Systolic blood pressure of 210 mmHg

Correct answer: Patient request to stop

According to AHA/ACC guidelines, a patient's request to stop is an absolute indication for terminating the test. While arrhythmias, ST depression, and hypertension are significant and may lead to test termination (often as relative indications), the patient's explicit desire to stop must be honored immediately.

Question 79: What kind of substance is administered intravenously during a stress test in order to image blood flow?

flourescent serum
a nuclear isotope (Correct answer)
C-12 atoms
a genetic marker

Correct answer: a nuclear isotope

Nuclear imaging and nuclear medicine diagnosis. The use of radioisotopes in diagnostic techniques in medicine is crucial. They can be used in conjunction with imaging tools that record the gamma rays emitted from within to image the dynamic processes occurring in various bodily areas.

Question 80: A patient with a DDD pacemaker shows pacing spikes before both P waves and QRS complexes on the ECG. What pacemaker mode is currently functioning?

VVI pacing — only the ventricle is being paced
AV sequential (DDD) pacing — both atrium and ventricle are being paced (Correct answer)
The pacemaker is malfunctioning
AAI pacing — only the atrium is being paced

Correct answer: AV sequential (DDD) pacing — both atrium and ventricle are being paced

Visible pacing spikes before both P waves and QRS complexes confirms that both the atrium and ventricle are being paced sequentially (DDD or DOO mode), which is the most physiologic form of pacing.

Question 81: A 24-hour Holter recording reveals 847 premature ventricular contractions (PVCs). Which characteristic would make this finding most concerning?

PVCs with a rate of less than 10 per hour
PVCs occurring during physical activity
PVCs occurring in runs of 3 or more (non-sustained VT) (Correct answer)
PVCs that are unifocal in morphology

Correct answer: PVCs occurring in runs of 3 or more (non-sustained VT)

Runs of 3 or more consecutive PVCs constitute non-sustained ventricular tachycardia, which is a much more concerning finding associated with higher risk for sustained VT or sudden cardiac death.

Question 82: During a treadmill stress test using the Bruce protocol, the first stage requires walking at what speed and grade?

3.4 mph at 14% grade
2.5 mph at 12% grade
4.2 mph at 16% grade
1.7 mph at 10% grade (Correct answer)

Correct answer: 1.7 mph at 10% grade

Stage 1 of the standard Bruce protocol requires walking at 1.7 mph (2.7 km/h) at 10% grade for 3 minutes, equivalent to approximately 5 METs of workload.

Question 83: A patient's Holter report notes 'total atrial fibrillation burden: 23%.' What does this mean?

The fibrillation had 23% of normal P wave amplitude
The patient had 23% of their beats as atrial fibrillatory waves
23% of the recording had artifact resembling AFib
The patient was in atrial fibrillation for approximately 23% of the total recording time (Correct answer)

Correct answer: The patient was in atrial fibrillation for approximately 23% of the total recording time

AF burden represents the percentage of total recording time during which the patient was in atrial fibrillation. A 23% burden in a 24-hour recording means approximately 5.5 hours were spent in AFib.

Question 84: What is the significance of the 'R-on-T' phenomenon in the setting of myocardial infarction?

R-on-T is a normal finding in sinus arrhythmia with no clinical significance
R-on-T only occurs in patients with complete heart block
A PVC that falls on the T wave of the preceding beat can trigger ventricular tachycardia or fibrillation because it occurs during the vulnerable period of ventricular repolarization (Correct answer)
R-on-T always causes immediate ventricular fibrillation

Correct answer: A PVC that falls on the T wave of the preceding beat can trigger ventricular tachycardia or fibrillation because it occurs during the vulnerable period of ventricular repolarization

R-on-T PVCs occur during the vulnerable period (relative refractory period, near the T wave apex) when ventricular muscle cells have varying degrees of repolarization, creating the ideal substrate for reentrant ventricular tachycardia or fibrillation.

Question 85: Which statement best describes the difference between a 24-hour Holter monitor and an event monitor?

A Holter records continuously for 24-48 hours; an event monitor records only when activated or triggered (Correct answer)
A Holter is worn externally; an event monitor is implanted
A Holter uses 12 leads; an event monitor uses only 1 lead
A Holter records only symptomatic episodes; an event monitor records continuously

Correct answer: A Holter records continuously for 24-48 hours; an event monitor records only when activated or triggered

Holter monitors record continuously for the entire wearing period (24-48 hours), while event monitors (loop recorders) store recordings only when the patient activates them or when an automatic trigger detects an abnormal rhythm.

Question 86: What is the most important absolute contraindication to exercise stress testing?

Acute myocardial infarction within the previous 2 days (Correct answer)
Mild aortic stenosis
Controlled hypertension with resting BP of 150/90
History of stable angina

Correct answer: Acute myocardial infarction within the previous 2 days

Acute myocardial infarction within 2 days is an absolute contraindication because exercise increases myocardial oxygen demand and can extend the area of infarction or precipitate ventricular arrhythmias in the setting of acute ischemia.

Question 87: On ECG, how can you distinguish a right ventricular apex pacemaker from a left ventricular pacemaker (as in CRT devices)?

Pacemaker origin cannot be determined from the surface ECG
Both RV and LV pacing show identical QRS morphology
RV apex pacing shows RBBB morphology; LV pacing shows LBBB morphology
RV apex pacing shows LBBB morphology in precordial leads; LV pacing shows RBBB morphology (Correct answer)

Correct answer: RV apex pacing shows LBBB morphology in precordial leads; LV pacing shows RBBB morphology

RV apex pacing depolarizes the heart starting from the right ventricle and spreading leftward, producing a LBBB-like pattern. LV epicardial pacing (as in CRT) activates the left ventricle first, producing a RBBB-like pattern.

Question 88: A patient is being screened for an exercise stress test. Which of the following conditions, if present and symptomatic, represents an absolute contraindication to proceeding with the test?

Previous coronary artery bypass surgery
History of stable angina
Severe aortic stenosis (Correct answer)
Controlled hypertension

Correct answer: Severe aortic stenosis

Symptomatic severe aortic stenosis is an absolute contraindication for exercise stress testing. Exertion in these patients can critically restrict cardiac output, leading to syncope, severe ischemia, or sudden cardiac death. The other options are not absolute contraindications.

Question 89: A CCT is monitoring a patient whose pacemaker is programmed to a lower rate of 60 bpm. The patient's intrinsic heart rate drops to 50 bpm, but no pacing spikes appear on the ECG, resulting in a long pause. This scenario most likely represents which pacemaker malfunction?

Normal pacemaker function
Undersensing
Oversensing (Correct answer)
Failure to capture

Correct answer: Oversensing

Oversensing occurs when the pacemaker incorrectly interprets electrical signals (e.g., muscle artifact, tall T-waves, or EMI) as intrinsic cardiac activity. This false detection inhibits the pacemaker from delivering a pacing stimulus when it is actually needed, causing a pause or a rate drop.

Question 90: During a resting ECG, a patient continues to shiver despite being asked to relax. What is the most likely artifact that will result, and how can it be minimized?

Wandering baseline; have the patient breathe faster
60 Hz interference; disconnect all IV pumps
Motion artifact; strap the patient's limbs to the table
Muscle tremor artifact (rapid, irregular oscillations obscuring the baseline); warm the patient with a blanket and re-attempt (Correct answer)

Correct answer: Muscle tremor artifact (rapid, irregular oscillations obscuring the baseline); warm the patient with a blanket and re-attempt

Shivering produces rapid, irregular, high-frequency muscle potentials that overlay the ECG baseline (somatic tremor artifact). Warming the patient with a blanket to stop shivering is the most effective solution.

Question 91: Wandering baseline artifact is most commonly caused by:

Patient talking during recording
Respiratory movement or poor electrode-skin contact (Correct answer)
Reversed limb lead placement
60 Hz electrical interference

Correct answer: Respiratory movement or poor electrode-skin contact

Wandering baseline is typically caused by respiratory movement or poor electrode-skin contact, making the baseline drift rhythmically up and down.

Question 92: What does the T wave on an ECG stand for?

Atrial depolarization
Ventricular repolarization (Correct answer)
Atrial repolarization
Ventricular depolarization

Correct answer: Ventricular repolarization

The ventricles start to repolarize right after the QRS. The faster and concluding portion of the repolarization is represented by the T wave. The P wave is a visual representation of atrial depolarization. The QRS complex symbolizes the depolarization of the ventricles. On the ECG, atrial repolarization is not visible.

Question 93: During the recovery phase of an exercise stress test, continuous monitoring of the patient's ECG and vital signs is essential. For how long should this monitoring typically continue?

For at least 6-8 minutes, or until ECG changes and symptoms resolve (Correct answer)
For 1 minute for every stage of exercise completed
Until the heart rate returns to precisely the resting baseline rate
Exactly 3 minutes post-exercise

Correct answer: For at least 6-8 minutes, or until ECG changes and symptoms resolve

The post-exercise recovery period is diagnostically important, as some ischemic changes or arrhythmias may only appear after the exercise has stopped. Standard procedure is to monitor the patient for a minimum of 6-8 minutes, and potentially longer if ECG abnormalities or patient symptoms persist or worsen.

Question 94: A 55-year-old patient cannot exercise on a treadmill due to severe arthritis. What is the most appropriate alternative to exercise stress testing?

Pharmacologic stress testing with vasodilators (adenosine/regadenoson) or dobutamine combined with imaging (Correct answer)
Rest ECG alone to evaluate for ischemia
The patient should be referred directly for coronary angiography without stress testing
No stress testing should be performed since exercise is not possible

Correct answer: Pharmacologic stress testing with vasodilators (adenosine/regadenoson) or dobutamine combined with imaging

Pharmacologic stress testing using vasodilators (adenosine, dipyridamole, regadenoson) or inotropic agents (dobutamine) combined with nuclear imaging or echocardiography is the established alternative for patients unable to exercise.

Question 95: What ECG characteristics define monomorphic ventricular tachycardia (VT)?

Wide QRS complexes at 40-60 bpm with AV dissociation
Three or more consecutive QRS complexes originating in the ventricles at a rate ≥ 100 bpm with identical QRS morphology from beat to beat (Correct answer)
Three PVCs with different QRS morphologies occurring consecutively
P waves at 300 bpm with regular QRS complexes at 150 bpm

Correct answer: Three or more consecutive QRS complexes originating in the ventricles at a rate ≥ 100 bpm with identical QRS morphology from beat to beat

Monomorphic VT is defined as three or more consecutive ventricular beats at ≥100 bpm (typically 140-200 bpm) with uniform (identical) QRS morphology in each lead, indicating a single ventricular origin for each beat.

Question 96: A 12-lead ECG shows pathological Q waves (>40 ms wide, >25% of R wave height) in leads II, III, and aVF. What do these represent?

Normal septal depolarization
Old inferior myocardial infarction (scar) (Correct answer)
Pericarditis
Right bundle branch block

Correct answer: Old inferior myocardial infarction (scar)

Pathological Q waves in the inferior leads indicate transmural myocardial necrosis in the inferior wall, representing old or evolving inferior MI.

Question 97: A technician observes a 'wandering baseline' on the ECG tracing, where the isoelectric line slowly moves up and down. Which of the following is a common cause of this artifact?

Incorrect paper speed.
AC electrical interference.
Expired electrode gel.
Patient's respiratory movements. (Correct answer)

Correct answer: Patient's respiratory movements.

A wandering baseline is often caused by patient movement, including the rise and fall of the chest during normal breathing. It can also be caused by poor electrode contact or loose electrodes.

Question 98: A patient with a VVIR pacemaker programmed to 60 bpm shows QRS complexes at a rate of 80 bpm with no pacemaker spikes. What is the most likely explanation?

The patient is experiencing VT
The pacemaker battery has failed
The pacemaker is malfunctioning with failure to output
The patient's intrinsic heart rate (80 bpm) exceeds the pacemaker's programmed lower rate (60 bpm), appropriately inhibiting pacing (Correct answer)

Correct answer: The patient's intrinsic heart rate (80 bpm) exceeds the pacemaker's programmed lower rate (60 bpm), appropriately inhibiting pacing

In demand (inhibited) pacing modes like VVI, if the patient's intrinsic rate exceeds the programmed lower rate, the pacemaker appropriately senses the intrinsic beats and inhibits its output. This is normal pacemaker behavior, not a malfunction.

Question 99: Which finding during exercise stress testing is an indication for immediate test termination?

Mild dyspnea that the patient tolerates
Sinus tachycardia at peak exercise
A normal increase in heart rate from 70 to 120 bpm
A drop in systolic blood pressure of more than 10 mmHg below resting baseline despite increasing workload (Correct answer)

Correct answer: A drop in systolic blood pressure of more than 10 mmHg below resting baseline despite increasing workload

A drop in systolic blood pressure of more than 10 mmHg below the pre-exercise resting level during increasing workload (exertional hypotension) is an absolute indication for test termination because it suggests severe left ventricular dysfunction or outflow obstruction.

Question 100: Blood returning from the lungs enters the heart through which structure?

Superior vena cava into the right atrium
Pulmonary artery into the right ventricle
Coronary sinus into the right atrium
Pulmonary veins into the left atrium (Correct answer)

Correct answer: Pulmonary veins into the left atrium

Oxygenated blood from the lungs returns to the heart via four pulmonary veins that drain into the left atrium, completing the pulmonary circulation circuit.

Question 101: Hypokalemia is most likely to produce which ECG abnormality?

Tall R waves in V1
Short QT interval
Peaked T waves and wide QRS
Prominent U waves and flattened T waves (Correct answer)

Correct answer: Prominent U waves and flattened T waves

Low potassium causes flattening or inversion of T waves and the appearance of prominent U waves, which can prolong the QU interval.

Question 102: A patient wearing a Holter monitor reports palpitations at 2:15 PM. What is the most important action by the technician?

Instruct the patient to press the event marker button (Correct answer)
Remove the monitor immediately
Increase the recording speed
Call 911 for the patient

Correct answer: Instruct the patient to press the event marker button

The event marker allows the patient to mark the exact time of symptoms so the cardiologist can correlate the rhythm strip with symptoms reported in the diary.

Question 103: When an ECG shows a completely negative P wave in lead I with a positive P wave in aVR, what electrode error has most likely occurred?

Left arm and right arm electrodes have been reversed (Correct answer)
V1 and V5 electrodes have been switched
Left leg and right leg electrodes have been reversed
Left arm and left leg electrodes have been reversed

Correct answer: Left arm and right arm electrodes have been reversed

Left arm/right arm reversal is the most common electrode placement error. It causes the P wave and QRS to invert in lead I (appearing as if lead I is read backwards) and makes aVR appear positive (looking like aVL).

Question 104: Which of the following are considered the standard bipolar limb leads, forming the basis of Einthoven's triangle?

aVR, aVL, aVF
V4, V5, V6
V1, V2, V3
I, II, III (Correct answer)

Correct answer: I, II, III

Leads I, II, and III are the standard bipolar limb leads. They are called 'bipolar' because they record the difference in electrical potential between two specific limb electrodes. These three leads form the sides of Einthoven's triangle, a foundational concept in electrocardiography.

Question 105: What advantages do thallium stress tests have over regular ECG stress tests?

More quickly identifies areas of myocardial ischemia in the heart
More accurately identifies the specific areas of reduced blood flow in the heart (Correct answer)
Is a safer test overall for the patient
The test is simpler to perform

Correct answer: More accurately identifies the specific areas of reduced blood flow in the heart

Nuclear stress tests, sometimes referred to as thallium stress tests, collect more detailed and precise data than straightforward ECG stress testing. When attempting to gauge the degree of coronary artery disease in a patient with a history of the condition, it is a useful test.

Question 106: What is the most common cause of 60 Hz AC interference on an ECG tracing?

Patient movement during recording
Electrode gel drying out
Improper grounding or nearby electrical equipment (Correct answer)
Respiratory variation

Correct answer: Improper grounding or nearby electrical equipment

AC interference at 60 Hz is caused by improper grounding or electromagnetic interference from nearby electrical equipment in the room.

Question 107: While performing a resting ECG, the technician notices a thick, uniform, and fuzzy baseline, characteristic of 60-cycle interference. What is the most likely cause of this artifact?

An electrode has become loose or detached.
The patient is talking or moving.
There is electrical interference from nearby equipment. (Correct answer)
The patient is cold and shivering.

Correct answer: There is electrical interference from nearby equipment.

A 60-cycle (or AC) interference artifact presents as a thick, consistent, fuzzy baseline. It is caused by electromagnetic interference from nearby electrical devices, such as power cords, patient beds, or mobile phones.

Question 108: To obtain a standard 12-lead ECG, how many electrodes are placed on the patient?

10 (Correct answer)
12
15
6

Correct answer: 10

A standard 12-lead ECG provides 12 different views of the heart's electrical activity, but it is recorded using only 10 electrodes: four limb electrodes (one on each arm and leg) and six precordial (chest) electrodes.

Question 109: Which of the following ions contributes most to the depolarizing current in pacemaker cells?

Sodium
Chloride
Potassium
Calcium (Correct answer)

Correct answer: Calcium

In cardiac pacemaker cells, relatively sluggish, inward calcium currents are principally responsible for carrying the depolarizing current. Fast sodium currents cause the depolarization in the majority of other depolarizing cells, including muscle cells. Cellular repolarization is aided by potassium.

Question 110: When reviewing a Holter report, the technician sees the notation 'SVE.' What does this abbreviation represent?

Severe ventricular event
Sinus ventricular escape
Subendocardial vascular event
Supraventricular ectopic beat (premature atrial contraction) (Correct answer)

Correct answer: Supraventricular ectopic beat (premature atrial contraction)

SVE stands for supraventricular ectopic beat, which is another term for a premature atrial contraction (PAC) or other ectopic beat originating above the ventricles.

Question 111: What is the significance of a 'pacing spike' that falls directly on a T wave in a pacemaker patient?

It represents an R-on-T phenomenon from undersensing that could theoretically induce ventricular fibrillation (Correct answer)
It represents proper atrial pacing triggering ventricular contraction
It is a normal finding during rapid heart rates when the T wave is close to the next QRS
It indicates the pacemaker is functioning normally in the AAI mode

Correct answer: It represents an R-on-T phenomenon from undersensing that could theoretically induce ventricular fibrillation

A pacing spike landing on the T wave (R-on-T phenomenon) results from undersensing — the pacemaker failed to detect the preceding intrinsic QRS and therefore fired at its escape interval, which happened to coincide with the vulnerable period (T wave) of ventricular repolarization.

Question 112: Which hand hygiene technique is required when caring for a patient with Clostridioides difficile (C. diff) infection?

Either soap/water or alcohol sanitizer — both are equivalent
Alcohol-based hand sanitizer applied for 30 seconds
Gloves alone are sufficient without handwashing
Soap and water handwashing — alcohol-based hand sanitizers are NOT effective against C. diff spores (Correct answer)

Correct answer: Soap and water handwashing — alcohol-based hand sanitizers are NOT effective against C. diff spores

C. difficile produces hardy spores that are resistant to alcohol-based hand sanitizers. Soap and water mechanically removes spores from hands and is the only effective hand hygiene method for C. diff.

Question 113: Which ECG leads most commonly show baseline wander due to respiratory movement?

Precordial leads V1–V6
Lead aVR exclusively
Right precordial leads (V1, V2) only
Inferior limb leads (II, III, aVF) (Correct answer)

Correct answer: Inferior limb leads (II, III, aVF)

The inferior limb leads (II, III, aVF) are most commonly affected by respiratory baseline wander as the limb electrodes move with breathing and the thorax expands.

Question 114: What is the hallmark ECG finding of left ventricular hypertrophy (LVH) using the Sokolow-Lyon criterion?

QRS duration > 120 ms
R in aVL > 11 mm only
S in V1 + R in V5 or V6 > 35 mm (Correct answer)
ST elevation in V1-V2

Correct answer: S in V1 + R in V5 or V6 > 35 mm

The Sokolow-Lyon criterion defines LVH as the sum of the S wave in V1 and the tallest R wave in V5 or V6 exceeding 35 mm.

Question 115: Which medication class is commonly used to achieve rate control in atrial fibrillation with rapid ventricular response?

Loop diuretics (furosemide)
Beta-blockers and non-dihydropyridine calcium channel blockers (diltiazem, verapamil) (Correct answer)
Anticoagulants (warfarin, apixaban)
Class IA antiarrhythmics (quinidine, procainamide)

Correct answer: Beta-blockers and non-dihydropyridine calcium channel blockers (diltiazem, verapamil)

Beta-blockers and non-dihydropyridine calcium channel blockers slow AV nodal conduction, reducing the ventricular response rate in AFib without necessarily converting it to sinus rhythm.

Question 116: A patient scheduled for a resting ECG reports having applied body lotion this morning. What is the best course of action for the CCT?

Wipe the electrode sites with a dry gauze pad before application.
Apply the electrodes directly over the lotion.
Clean the electrode sites with an alcohol wipe to remove the lotion. (Correct answer)
Reschedule the ECG for another day.

Correct answer: Clean the electrode sites with an alcohol wipe to remove the lotion.

Oils, lotions, and sweat on the skin can interfere with electrode adhesion and conductivity, leading to a poor-quality tracing. The proper procedure is to clean the skin at the electrode sites with an alcohol wipe and allow it to dry completely before applying the electrodes.

Question 117: A detached or loose electrode is most likely to produce which type of artifact?

Wandering baseline only in limb leads
60 Hz AC interference throughout all leads
A flat line or intermittent signal loss in the affected lead (Correct answer)
Somatic tremor in the affected lead

Correct answer: A flat line or intermittent signal loss in the affected lead

A loose or detached electrode interrupts the electrical circuit, producing a flat line or intermittent signal dropout in the lead(s) using that electrode.

Question 118: On a Holter recording, you observe episodes where the P wave morphology changes beat to beat and the PP intervals vary. What rhythm does this represent?

Atrial flutter
Wandering atrial pacemaker (Correct answer)
Third-degree heart block
Normal sinus rhythm with artifact

Correct answer: Wandering atrial pacemaker

Wandering atrial pacemaker is characterized by at least 3 different P wave morphologies within the same lead and varying PP intervals, reflecting the pacemaker site shifting between the SA node, other atrial locations, and the AV junction.

Question 119: To minimize motion artifact during ECG recording, the technician should:

Ensure the patient is relaxed, warm, and comfortably positioned (Correct answer)
Increase paper speed to 50 mm/sec
Ask the patient to hold their breath throughout the entire recording
Reduce the gain setting on the ECG machine

Correct answer: Ensure the patient is relaxed, warm, and comfortably positioned

Ensuring the patient is relaxed, warm, and comfortable minimizes muscle tension and involuntary movement, which are primary sources of motion artifact.

Question 120: A Certified Cardiographic Technician is preparing to perform a standard 12-lead ECG. At what speed should the technician set the electrocardiograph machine to ensure the tracing is recorded according to industry standards?

50 mm/sec
25 mm/sec (Correct answer)
10 mm/sec
100 mm/sec

Correct answer: 25 mm/sec

The standard paper speed for recording a 12-lead ECG is 25 mm/sec. This speed allows for accurate measurement and interpretation of wave forms, intervals, and segments. Running the machine at a different speed without a specific clinical indication would distort the ECG and could lead to misinterpretation.

Question 121: What is 'pacemaker syndrome,' and in which pacing mode does it most commonly occur?

Oversensing causing the pacemaker to stop working
Symptoms (fatigue, dizziness, pulsations in neck) caused by loss of AV synchrony, most common with VVI pacing (Correct answer)
Failure to capture causing repeated near-syncopal episodes
Infection around the pacemaker generator causing systemic symptoms

Correct answer: Symptoms (fatigue, dizziness, pulsations in neck) caused by loss of AV synchrony, most common with VVI pacing

Pacemaker syndrome describes the hemodynamic and symptomatic consequences of AV dissociation caused by ventricular-only pacing (VVI), where the atria contract against closed AV valves, causing retrograde cannon A waves and reduced cardiac output.

Question 122: An ECG rhythm strip from a patient with a pacemaker shows distinct pacing spikes that are not followed by any electrical activity (neither a P wave nor a QRS complex). This finding is best described as which type of pacemaker malfunction?

Failure to pace
Failure to capture (Correct answer)
Oversensing
Undersensing

Correct answer: Failure to capture

Failure to capture occurs when the pacemaker delivers an electrical stimulus (the spike), but the stimulus is insufficient to depolarize the myocardium. As a result, no P wave or QRS complex is generated after the spike.

Question 123: What blood pressure response during exercise stress testing is considered normal?

Blood pressure does not change during exercise in a healthy individual
Both systolic and diastolic BP increase proportionally by 30-40 mmHg
Systolic BP progressively rises 10-50 mmHg above rest; diastolic BP remains unchanged or decreases slightly (Correct answer)
Systolic BP decreases and diastolic BP increases throughout exercise

Correct answer: Systolic BP progressively rises 10-50 mmHg above rest; diastolic BP remains unchanged or decreases slightly

Normally during exercise, systolic blood pressure rises progressively due to increased cardiac output, while diastolic blood pressure remains relatively stable or may decrease slightly due to peripheral vasodilation in exercising muscles.

Question 124: To reduce somatic tremor artifact in an anxious or cold patient, the technician should FIRST:

Apply additional electrodes in parallel to average the signal
Increase the recording speed to 50 mm/sec
Reassure the patient, ensure warmth, and allow time to relax before recording (Correct answer)
Immediately activate the artifact filter on the ECG machine

Correct answer: Reassure the patient, ensure warmth, and allow time to relax before recording

Addressing patient comfort and anxiety through reassurance and warmth reduces muscle tension at its source before resorting to technical workarounds.

Question 125: A CCT is reviewing an ECG strip that shows a regular vertical spike immediately preceding each P wave, followed by a normal QRS complex. The patient's heart rate is 70 bpm. Which of the following is the most accurate interpretation?

Ventricular paced rhythm
Dual-chamber paced rhythm
Atrial paced rhythm (Correct answer)
Failure to capture

Correct answer: Atrial paced rhythm

This ECG demonstrates a normally functioning atrial pacemaker. The pacemaker spike initiates atrial depolarization, creating the P wave. The impulse then travels normally through the AV node and ventricles, resulting in a native QRS complex.

Question 126: Which of the following ECG findings is the hallmark characteristic of Third-Degree Atrioventricular (AV) Block?

Complete AV dissociation with atrial rate faster than ventricular rate (Correct answer)
A constant PR interval with intermittently dropped QRS complexes
Progressively lengthening PR interval until a QRS is dropped
A heart rate consistently below 40 bpm with narrow QRS complexes

Correct answer: Complete AV dissociation with atrial rate faster than ventricular rate

Third-degree, or complete, AV block is defined by the complete absence of conduction between the atria and ventricles. This results in AV dissociation, where the P waves (atrial activity) and QRS complexes (ventricular activity) are independent of each other, with the atrial rate typically being faster than the ventricular escape rate.

Question 127: Which ECG pattern is described as diffuse concave ('saddle-back') ST elevation in most leads with PR depression, without reciprocal changes?

Pericarditis (Correct answer)
STEMI
Brugada syndrome
Early repolarization variant

Correct answer: Pericarditis

Acute pericarditis causes diffuse concave ST elevation and PR depression (especially in II and aVF) in most leads without the reciprocal depression seen in STEMI.

Question 128: When a patient cannot remain still during an ECG due to uncontrollable tremors, the technician should:

Cancel the ECG and reschedule when the patient is better
Proceed without documentation and submit the tracing as normal
Apply pressure bandages to immobilize the extremities
Document the artifact, note the clinical condition, and record the best quality tracing possible (Correct answer)

Correct answer: Document the artifact, note the clinical condition, and record the best quality tracing possible

The technician should document the artifact type and clinical reason (e.g., Parkinson's, shivering) and provide the best available tracing for physician interpretation.

Question 129: A patient's ECG strip shows a regular rhythm with a rate of 45 bpm. The QRS complexes are wide (0.14 seconds), and there are no discernible P waves associated with the QRS complexes. Which of the following rhythms is most likely represented?

Idioventricular rhythm (Correct answer)
Junctional escape rhythm
Sinus bradycardia with bundle branch block
Third-degree AV block with a junctional escape

Correct answer: Idioventricular rhythm

Idioventricular rhythm is characterized by a regular, slow ventricular rate (typically 20-40 bpm, but sometimes up to 50), wide QRS complexes (≥0.12s), and the absence of associated P waves. It acts as a safety mechanism when higher pacemakers fail.

Question 130: Artifact that closely mimics atrial fibrillation on an ECG is most commonly caused by:

60 Hz AC interference
Patient shivering or fine muscle tremor (somatic tremor) (Correct answer)
Low-frequency baseline wander from respiration
Reversed precordial lead placement

Correct answer: Patient shivering or fine muscle tremor (somatic tremor)

Somatic tremor, particularly shivering, produces rapid irregular oscillations that can closely resemble the fibrillatory baseline of atrial fibrillation.

Question 131: What lead is most susceptible to respiration?

Lead III (Correct answer)
Lead I
V2
V4

Correct answer: Lead III

Since Lead III is the component most impacted by respiration, the waveforms may alter according to the respiratory cycle. A Q wave that only arises in lead III and is not connected to other equivalent changes in other leads is therefore not relevant.

CCT - Certified Cardiographic Technician Exam

The CCT exam, administered by Cardiovascular Credentialing International (CCI), certifies technicians who perform ECGs, Holter monitoring, and stress testing procedures.

130

Questions

120 min

Time Limit

72%

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