CMC Cardiac Arrhythmia Management

Question 1

A patient presents with a narrow-complex tachycardia at 160 bpm with regular rhythm and retrograde P waves. Which arrhythmia is most likely?

Accepted Answer

Atrioventricular nodal reentrant tachycardia (AVNRT)

Answer

Atrial fibrillation

Answer

Ventricular tachycardia

Answer

Atrial flutter with 2:1 block

Question 2

Which finding on a 12-lead ECG is most characteristic of Wolff-Parkinson-White (WPW) syndrome during sinus rhythm?

Accepted Answer

Short PR interval with a delta wave

Answer

Prolonged PR interval greater than 200 ms

Answer

Widened QRS with left bundle branch block morphology

Answer

ST-segment elevation in leads V1-V4

Question 3

A patient with symptomatic bradycardia due to complete heart block is hemodynamically unstable. What is the immediate treatment of choice?

Accepted Answer

Transcutaneous pacing

Answer

Oral metoprolol 25 mg

Answer

IV adenosine 6 mg bolus

Answer

Synchronized cardioversion

Question 4

On telemetry, you observe a regular rhythm at 75 bpm with no visible P waves and narrow QRS complexes. Which rhythm is most consistent with this pattern?

Accepted Answer

Accelerated junctional rhythm

Answer

Atrial fibrillation

Answer

Sinus arrest with junctional escape

Answer

First-degree AV block

Question 5

Which medication is the first-line pharmacologic treatment for stable monomorphic ventricular tachycardia in a patient with preserved ejection fraction?

Accepted Answer

Amiodarone IV

Answer

Adenosine IV

Answer

Digoxin IV

Answer

Diltiazem IV

Question 6

A patient develops torsades de pointes during ECG monitoring. Which electrolyte abnormality is most commonly associated with this arrhythmia?

Accepted Answer

Hypomagnesemia

Answer

Hypernatremia

Answer

Hyperkalemia

Answer

Hypercalcemia

Question 7

Which feature best distinguishes atrial flutter from atrial fibrillation on an ECG?

Accepted Answer

Sawtooth flutter waves at ~300 bpm in atrial flutter

Answer

Irregular ventricular response in atrial flutter

Answer

Narrow QRS complexes in atrial fibrillation only

Answer

Absence of P waves in atrial flutter