AF Electrophysiology & ECG Interpretation 2

Question 1

What primary electrophysiological mechanism underlies atrial fibrillation?

Accepted Answer

Multiple reentrant electrical wavelets within the atria

Answer

AF is driven primarily by multiple simultaneous reentrant wavelets circulating chaotically through atrial tissue, preventing coordinated atrial contraction.

Question 2

A patient with Wolff-Parkinson-White (WPW) syndrome who develops atrial fibrillation is at risk for which dangerous ECG pattern?

Accepted Answer

Wide, bizarre QRS complexes due to rapid accessory pathway conduction

Answer

In WPW with AF, rapid conduction through the accessory pathway bypasses the rate-limiting AV node, producing wide bizarre QRS complexes that can degenerate into ventricular fibrillation.

Question 3

Which finding best distinguishes multifocal atrial tachycardia (MAT) from atrial fibrillation on ECG?

Accepted Answer

MAT displays at least 3 distinct P wave morphologies with varying PR intervals

Answer

MAT is identified by three or more distinct P wave morphologies with varying PR intervals and an isoelectric baseline, distinguishing it from AF's absent P waves.

Question 4

How would you describe the f-waves (fibrillatory waves) characteristic of atrial fibrillation?

Accepted Answer

Chaotic, irregular undulations varying in amplitude and morphology

Answer

Fibrillatory waves in AF are chaotic, irregular baseline undulations that vary in amplitude and morphology, reflecting disorganized atrial electrical activity.

Question 5

'Coarse' atrial fibrillation is differentiated from 'fine' atrial fibrillation on ECG by:

Accepted Answer

Coarse AF has f-waves greater than 1mm in amplitude

Answer

Coarse AF has fibrillatory waves greater than 1mm in amplitude, often associated with chronic conditions or metabolic disturbances, while fine AF has barely perceptible baseline undulations.

(AF) Atrial Fibrillation Certification Practice Test

(AF) Atrial Fibrillation Certification Practice Test

AF Electrophysiology & ECG Interpretation 2