CCT Ambulatory (Holter) Monitoring 2 — Questions and Answers
Question 1: 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
- Call 911 for the patient
- Increase the recording speed
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.
Holter monitors are equipped with an event marker button specifically for patients to press when they feel symptoms. This timestamps the recording so the interpreting physician can find and analyze the rhythm during the symptomatic period. Without this correlation, the clinical value of ambulatory monitoring is significantly reduced.
Question 2: Which electrode placement is used for the CM5 lead in Holter monitoring?
- Positive electrode at V5 position, negative at manubrium (Correct answer)
- Positive electrode at V1, negative at left arm
- Positive electrode at right leg, negative at left leg
- Positive electrode at manubrium, negative at V5
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.
CM5 is one of the most clinically significant Holter leads because it closely approximates lead V5 and is highly sensitive to left ventricular ischemia. The positive electrode is placed at the V5 position (5th intercostal space, anterior axillary line) and the negative electrode at the top of the sternum (manubrium). This configuration maximizes detection of ST-segment depression during ischemic events.
Question 3: During Holter monitor hookup, a technician notices the patient has a hairy chest. What is the best approach?
- Shave only the small areas where electrodes will be placed (Correct answer)
- Apply electrodes over the hair without preparation
- Cancel the test until the patient shaves
- Apply extra adhesive tape over the electrodes
Correct answer: Shave only the small areas where electrodes will be placed
Shaving only the small electrode placement sites ensures good skin contact and reduces artifact while minimizing patient discomfort and unnecessary hair removal.
Hair under electrodes prevents proper adhesion and creates motion artifact that can make the recording uninterpretable. The correct technique is to clip or shave only the small areas (approximately 3-4 cm diameter) where each electrode will be placed. The skin should also be cleaned with an alcohol prep pad and allowed to dry before electrode application to remove oils and dead skin cells.
Question 4: A 24-hour Holter recording reveals 847 premature ventricular contractions (PVCs). Which characteristic would make this finding most concerning?
- PVCs occurring in runs of 3 or more (non-sustained VT) (Correct answer)
- PVCs that are unifocal in morphology
- PVCs occurring during physical activity
- PVCs with a rate of less than 10 per hour
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.
While isolated PVCs are common and often benign, consecutive PVCs (couplets, triplets, runs) indicate that the ectopic focus can sustain itself and drive the heart. Three or more consecutive PVCs at a rate greater than 100 bpm meets the definition of non-sustained VT, which carries prognostic significance especially in patients with structural heart disease. Unifocal PVCs during activity or at low frequency are generally less concerning.
Question 5: 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 records only symptomatic episodes; an event monitor records continuously
- A Holter is worn externally; an event monitor is implanted
- A Holter uses 12 leads; an event monitor uses only 1 lead
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.
The key distinction is continuous vs. triggered recording. Holter monitors are ideal for patients with daily or near-daily symptoms because they capture all rhythms over the wearing period. Event monitors, including external loop recorders and implantable loop recorders, are better for infrequent symptoms because they can be worn for weeks to months and only store clinically relevant events, either patient-activated or algorithm-triggered.
Question 6: When reviewing a Holter report, the technician sees the notation 'SVE.' What does this abbreviation represent?
- Supraventricular ectopic beat (premature atrial contraction) (Correct answer)
- Severe ventricular event
- Sinus ventricular escape
- Subendocardial vascular event
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.
SVE (supraventricular ectopic) refers to any premature beat originating above the bundle of His — primarily PACs but also junctional premature beats. These are distinguished from PVCs by their narrow QRS morphology (assuming no aberrant conduction) and their origin in the atria or AV junction. SVEs are extremely common in the general population and are usually benign, though frequent SVEs can predict atrial fibrillation development.
CCT Ambulatory (Holter) Monitoring 2
A patient wearing a Holter monitor reports palpitations at 2:15 PM.
What is the most important action by the technician?