AF Electrophysiology & ECG Interpretation 3

Question 1

What is the standard method for estimating ventricular rate in atrial fibrillation on a rhythm strip?

Accepted Answer

Counting QRS complexes in a 6-second strip and multiplying by 10

Answer

Because RR intervals are irregular in AF, ventricular rate is estimated by counting QRS complexes over a 6-second strip and multiplying by 10 to extrapolate beats per minute.

Question 2

Which ECG monitoring modality is most appropriate for detecting intermittent paroxysmal AF in an outpatient setting?

Accepted Answer

24-hour Holter monitor

Answer

A 24-hour Holter monitor continuously records cardiac rhythm and significantly improves detection rates for paroxysmal AF compared to spot ECGs.

Question 3

An implantable loop recorder (ILR) is MOST indicated in a patient with:

Accepted Answer

Unexplained stroke (cryptogenic) suspected to be AF-related

Answer

ILRs provide continuous long-term ECG monitoring up to 3 years and are most valuable for detecting paroxysmal AF as the cause of cryptogenic stroke.

Question 4

After successful electrical cardioversion of atrial fibrillation, which ECG finding confirms restoration of sinus rhythm?

Accepted Answer

Return of distinct P waves preceding each QRS complex

Answer

Restoration of sinus rhythm after cardioversion is confirmed by the reappearance of organized P waves before each QRS, indicating the SA node has resumed as the primary pacemaker.

Question 5

In atrial fibrillation, which ECG lead is the standard choice for performing a rhythm strip assessment?

Accepted Answer

Lead II

Answer

Lead II runs parallel to the inferior axis and produces the most upright, clear P waves and QRS complexes, making it the standard lead for rhythm strip analysis.

(AF) Atrial Fibrillation Certification Practice Test

(AF) Atrial Fibrillation Certification Practice Test

AF Electrophysiology & ECG Interpretation 3