ECG ECG Rhythm Interpretation

Question 1

What are the hallmark ECG findings of atrial fibrillation?

Accepted Answer

Irregularly irregular rhythm with absent P waves and fibrillatory baseline

Answer

Atrial fibrillation shows an irregularly irregular ventricular rhythm (varying R-R intervals), absence of organized P waves replaced by fibrillatory baseline activity, and usually narrow QRS complexes.

Question 2

How do you differentiate between ventricular tachycardia and supraventricular tachycardia with aberrancy?

Accepted Answer

VT shows AV dissociation, fusion/capture beats, and concordance; SVT with aberrancy usually has preceding P waves

Answer

Key VT indicators include AV dissociation, fusion/capture beats, extreme axis deviation, and QRS concordance. SVT with aberrancy typically shows preceding atrial activity and a bundle branch block pattern.

Question 3

What does ST elevation on an ECG indicate?

Accepted Answer

Acute myocardial injury, most commonly from coronary artery occlusion causing a STEMI

Answer

ST elevation typically indicates acute myocardial injury from coronary artery occlusion (STEMI), though it can also occur in pericarditis, early repolarization, left ventricular aneurysm, and other conditions.

Question 4

What are the three degrees of AV heart block?

Accepted Answer

First degree (prolonged PR), second degree (dropped beats), and third degree (complete dissociation between P waves and QRS)

Answer

First degree shows prolonged PR interval (>0.20s), second degree has intermittently dropped QRS complexes (Mobitz I with progressive PR prolongation, Mobitz II with sudden drops), and third degree shows complete AV dissociation.

Question 5

What ECG findings suggest hyperkalemia?

Accepted Answer

Tall peaked T waves, widened QRS, flattened P waves, and potentially sine wave pattern

Answer

Hyperkalemia produces progressive ECG changes: peaked T waves, PR prolongation, P wave flattening, QRS widening, and eventually a sine wave pattern that can degenerate into ventricular fibrillation.

ECG (Electrocardiogram) Practice Test

ECG (Electrocardiogram) Practice Test

ECG ECG Rhythm Interpretation