ACSM-EP Electrocardiography 5 — Questions and Answers
Question 1: Which ECG finding during exercise testing is considered a reason for immediate test termination?
- Heart rate increase above 85% of age-predicted maximum
- New onset of sustained ventricular tachycardia (Correct answer)
- Minor upsloping ST depression of 0.5 mm
- Development of first-degree AV block
Correct answer: New onset of sustained ventricular tachycardia
Sustained ventricular tachycardia is an absolute indication to stop an exercise test immediately due to the risk of deterioration into ventricular fibrillation.
Question 2: On an ECG, what does a pathological Q wave indicate?
- Right bundle branch block
- Previous myocardial infarction with myocardial necrosis (Correct answer)
- Left ventricular hypertrophy
- Vagal-mediated slowing
Correct answer: Previous myocardial infarction with myocardial necrosis
Pathological Q waves (>0.04 seconds wide or >25% of R-wave amplitude) reflect electrically silent myocardial scar tissue from a prior transmural infarction.
Question 3: Which condition is associated with a prolonged QTc interval that could increase risk during vigorous exercise?
- Atrial fibrillation
- Long QT syndrome (LQTS) (Correct answer)
- Wolff-Parkinson-White syndrome
- Bundle branch block
Correct answer: Long QT syndrome (LQTS)
Long QT syndrome prolongs ventricular repolarization, creating susceptibility to torsades de pointes (polymorphic VT), which exercise or sympathetic activation can trigger.
Question 4: The P-wave on a standard ECG represents which cardiac event?
- Ventricular depolarization
- Atrial repolarization
- Atrial depolarization (Correct answer)
- AV nodal conduction
Correct answer: Atrial depolarization
The P-wave represents the spread of electrical impulse (depolarization) through both atria, triggering atrial contraction; atrial repolarization is hidden within the QRS.
Question 5: During ECG monitoring, a rhythm strip shows regularly irregular R-R intervals that increase during inspiration and decrease during expiration. This most likely indicates:
- Second-degree Mobitz II block
- Sinus arrhythmia (Correct answer)
- Atrial flutter with variable block
- Multifocal atrial tachycardia
Correct answer: Sinus arrhythmia
Sinus arrhythmia is a normal variation where R-R intervals cyclically lengthen with inspiration and shorten with expiration due to changes in vagal tone.
Question 6: Which precordial lead transition zone finding suggests right axis shift or right ventricular dominance?
- R/S ratio >1 occurring at V3 or V4
- R/S ratio >1 occurring as early as V1 or V2 (Correct answer)
- Absent R waves across all precordial leads
- R/S ratio >1 first appearing at V5 or V6
Correct answer: R/S ratio >1 occurring as early as V1 or V2
Dominant R waves in V1–V2 (early transition or reversed R-wave progression) suggests right ventricular hypertrophy or posterior MI rather than normal left-to-right R-wave growth.
Question 7: An exercise physiologist notes that a client's heart rate fails to increase appropriately during a progressive exercise test. This phenomenon is called:
- Chronotropic incompetence (Correct answer)
- Negative chronotropy
- Rate-pressure product failure
- Autonomic dysregulation
Correct answer: Chronotropic incompetence
Chronotropic incompetence is defined as the inability to achieve ≥80% of age-predicted maximum heart rate without beta-blocker use and is associated with increased cardiovascular risk.
ACSM-EP Electrocardiography 5
Which ECG finding during exercise testing is considered a reason for immediate test termination?