ACLS ACLS Cardiac Rhythms & ECG Interpretation 3

Question 1

Which of the following rhythms is SHOCKABLE in the ACLS pulseless arrest algorithm?

Accepted Answer

Ventricular fibrillation (VF)

Answer

Ventricular fibrillation and pulseless ventricular tachycardia are the only two shockable rhythms in the ACLS cardiac arrest algorithm.

Question 2

What QTc duration is generally considered prolonged and at risk for torsades de pointes?

Accepted Answer

>500 ms

Answer

A QTc >500 ms significantly increases the risk for torsades de pointes (TdP) and sudden cardiac death.

Question 3

Accelerated idioventricular rhythm (AIVR) following myocardial infarction typically has what rate?

Accepted Answer

40–100 bpm

Answer

AIVR has a rate of 40–100 bpm and is often a benign reperfusion arrhythmia requiring no treatment.

Question 4

Which lead is most useful for identifying P waves and distinguishing atrial arrhythmias in ACLS monitoring?

Accepted Answer

Lead II or V1

Answer

Lead II provides the best visualization of P waves due to its alignment with the atrial vector, while V1 clearly shows flutter waves and retrograde P waves.

Question 5

A patient presents with a regular wide-complex tachycardia at 200 bpm. Which ECG finding would MOST support a diagnosis of ventricular tachycardia over SVT with aberrancy?

Accepted Answer

AV dissociation (P waves marching through independently)

Answer

AV dissociation — independent P waves unrelated to QRS complexes — is the most reliable ECG criterion distinguishing VT from SVT with aberrancy.

ACLS Practice Test

ACLS Practice Test

ACLS ACLS Cardiac Rhythms & ECG Interpretation 3