ACSM-EP Electrocardiography

Question 1

A resting 12-lead ECG shows a regular rhythm with a PR interval of 0.26 seconds and every P wave followed by a QRS. What is the interpretation?

Accepted Answer

First-degree AV block

Answer

A consistently prolonged PR interval above 0.20 s with every P conducted is first-degree AV block.

Question 2

During an exercise test, which ST segment change is the standard ECG criterion for a positive (ischemic) response?

Accepted Answer

Horizontal or downsloping ST depression of 1 mm or more, 60-80 ms after the J point

Answer

Horizontal or downsloping ST depression of at least 1 mm (0.1 mV) measured 60-80 ms after the J point indicates ischemia.

Question 3

On a 6-second rhythm strip with a regular rhythm, the R-R interval spans 4 large boxes. What is the heart rate?

Accepted Answer

75 bpm

Answer

Heart rate = 300 divided by the number of large boxes between R waves = 300/4 = 75 bpm.

Question 4

During an exercise test, which rhythm finding requires immediate termination of the test?

Accepted Answer

Sustained ventricular tachycardia

Answer

Sustained ventricular tachycardia is an absolute indication to stop exercise because it can degenerate to ventricular fibrillation.

Question 5

A client has ST elevation in leads II, III, and aVF on a resting ECG. Which myocardial wall is affected?

Accepted Answer

Inferior wall

Answer

Leads II, III, and aVF view the inferior wall of the left ventricle, usually supplied by the right coronary artery.

ACSM Practice Test