Free EKG Certification MCQ Question and Answers — Questions and Answers

Question 1: Which leads are deemed to be subpar leads?

V1, II
I, II, and III
II, III, and aVR
II, III, and aVF (Correct answer)

Correct answer: II, III, and aVF

Leads II, III, and aVF are collectively known as the inferior leads. They provide an electrical view of the inferior wall of the left ventricle. These leads are particularly important for diagnosing inferior myocardial infarctions, as changes in their ST segments or Q waves can indicate damage to this specific heart region.

Question 2: What leads fall under the category of (left) lateral leads?

II, III
V5,V6
I aVR
I, aVL (Correct answer)

Correct answer: I, aVL

Leads I and aVL are classified as the high lateral leads, offering an electrical perspective of the high lateral wall of the left ventricle. Along with precordial leads V5 and V6 (low lateral leads), they help assess the lateral aspect of the heart. These leads are crucial for detecting lateral myocardial ischemia or infarction.

Question 3: Name the location of V2 that is correct:

5th right intercostal space
5th left intercostal space
4th right intercostal space (Correct answer)
4th left intercostal space

Correct answer: 4th right intercostal space

Lead V2 is correctly placed in the fourth intercostal space, just to the right of the sternum. This precise anatomical placement is part of the standard 12-lead EKG system, ensuring consistent and accurate recording of the heart's electrical activity. Proper lead placement is fundamental for reliable EKG interpretation.

Question 4: Give the location for V4 a name.

5th intercostal space midaxillary line
5th intercostal space, midclavicular line (Correct answer)
5th intercostal space, anterior axillary line
Who cares

Correct answer: 5th intercostal space, midclavicular line

Lead V4 is positioned in the fifth intercostal space, along the midclavicular line on the left side of the chest. This placement is crucial for obtaining an electrical view of the anterior wall of the left ventricle. It is a key lead for assessing anterior myocardial conditions.

Question 5: The V3 should be placed as follows:

Directly between leads V2 and V3
Directly between leads V3 and V4
Directly between leads V1 and V4
Directly between leads V2 and V4 (Correct answer)

Correct answer: Directly between leads V2 and V4

Lead V3 is placed directly between the positions of V2 and V4. V2 is at the fourth intercostal space, left sternal border, and V4 is at the fifth intercostal space, left midclavicular line. This intermediate placement ensures a smooth transition in the electrical view across the anterior chest wall, providing a comprehensive anterior perspective.

Question 6: Which perspective of the heart do leads V3–V4 provide?

Lateral
Posterior
Anterior (Correct answer)
None of these

Correct answer: Anterior

Leads V3 and V4 are part of the precordial (chest) leads that specifically provide an anterior view of the heart. V3 is considered anteroseptal, and V4 is anterior. Together, they are essential for detecting abnormalities, such as myocardial infarction, in the anterior wall of the left ventricle.

Question 7: Which lead better exhibits the P wave?

V1
AvF
III
Leads II (Correct answer)

Correct answer: Leads II

Lead II is typically the best lead to visualize the P wave because its electrical axis is generally aligned with the direction of atrial depolarization. This alignment results in a clear, upright P wave, making it easier to assess atrial activity, rhythm, and morphology. It is often used as the primary rhythm strip lead.

Question 8: Which lead do you think a BIPHASIC P wave would be in?

V3
V1 (Correct answer)
V5-V6
V2-V3

Correct answer: V1

A biphasic P wave, characterized by both an upward and a downward deflection, is most commonly observed in lead V1. This occurs because V1 is positioned over the right atrium, and the electrical impulse first moves towards V1 (positive deflection from right atrial depolarization) and then away from V1 (negative deflection from left atrial depolarization).

Question 9: Which leads in the QRS complex would you see a Deep S wave?

V3, v4
V1, V2 (Correct answer)
V1
V5,v6

Correct answer: V1, V2

In leads V1 and V2, which are positioned over the right ventricle and interventricular septum, the QRS complex typically shows a small R wave followed by a deep S wave. This pattern reflects the initial septal depolarization moving away from these leads, followed by the dominant left ventricular depolarization also moving away from V1 and V2.

Question 10: Where does the R wave exceed the S wave in size?

Lead v2
Lead v1
Lead v4 (Correct answer)
None of these

Correct answer: Lead v4

The R wave progression across the precordial leads (V1-V6) involves the R wave gradually increasing in size while the S wave decreases. In a normal EKG, the R wave typically becomes larger than the S wave (R > S) around lead V3 or V4, indicating the transition zone where the electrical forces of the left ventricle become dominant.

Question 11: When it is depressed, what section exhibits a symptom of significant pathology in the condition?

QT
R-R
PR
ST (Correct answer)

Correct answer: ST

The ST segment is a critical part of the EKG for diagnosing myocardial ischemia or injury. ST segment depression or elevation is a hallmark sign of acute coronary syndromes. Depression often indicates ischemia (reduced blood flow), while elevation typically signifies an acute myocardial infarction (heart attack), making it a significant pathological indicator.

Question 12: What wave is ventricular repolarization represented by?

T wave (Correct answer)
Q wave
P wave
U wave

Correct answer: T wave

The T wave on an EKG represents ventricular repolarization, which is the electrical recovery of the ventricles. This process allows the ventricular muscle cells to return to their resting state and prepare for the next depolarization. Abnormalities in the T wave can indicate various cardiac conditions, including ischemia or electrolyte imbalances.

Question 13: On the EKG, an R-R interval is represented by .

One complete cardiac cycle (Correct answer)
Inferior MI
Rest and Relaxation
Two complete cardiac cycles

Correct answer: One complete cardiac cycle

The R-R interval on an EKG measures the time between two consecutive R waves, which mark the peak of ventricular depolarization. This interval precisely represents the duration of one complete cardiac cycle, from one ventricular contraction to the next. It is fundamental for calculating heart rate and assessing the regularity of the heart rhythm.

Question 14: Which of these conditions has a connection to the T waves in the brain?

Traumatic brain injury
Intracranial bleed (Correct answer)
Ischemic stroke
All of these

Correct answer: Intracranial bleed

Intracranial bleeds can significantly impact the brain's autonomic nervous system, leading to characteristic EKG changes. These changes often manifest as deeply inverted or giant T waves, sometimes called 'cerebral T waves,' which are distinct from those caused by cardiac ischemia. This phenomenon is thought to be mediated by increased intracranial pressure and sympathetic overactivity affecting myocardial repolarization.

Question 15: The typical QRS duration is

>0,20
>0,10
<0,18
<0,10 (Correct answer)

Correct answer: <0,10

The QRS complex represents the electrical depolarization of the ventricles, leading to their contraction. In a healthy heart, this process occurs rapidly, resulting in a typical QRS duration of less than 0.10 seconds (or 100 milliseconds). A prolonged QRS duration can indicate a delay in ventricular conduction, such as a bundle branch block or ventricular hypertrophy.

Question 16: occurs when cardiac muscle is deprived of oxygen, causing the tissue to perish.

Cardiac palpitations
Myocarditis
Myocardial infarction (Correct answer)
Paroxysmal tachycardia

Correct answer: Myocardial infarction

Myocardial infarction (MI), commonly known as a heart attack, occurs when there is a severe and prolonged reduction or blockage of blood flow to a part of the heart muscle. This lack of oxygen (ischemia) causes the affected cardiac tissue to die (necrosis). The perishing tissue can no longer function, leading to impaired heart pumping ability.

Free EKG Certification MCQ Question and Answers

Which leads are deemed to be subpar leads?