CMC Cardiac Arrhythmia Management 3

Question 1

A patient develops sudden onset palpitations and an ECG shows a regular wide-complex tachycardia at 220 bpm with a delta wave. WPW syndrome is suspected. Which drug is contraindicated in this setting?

Accepted Answer

IV adenosine

Answer

IV procainamide

Answer

IV amiodarone

Answer

Electrical cardioversion

Question 2

Which finding confirms a successful catheter ablation of an accessory pathway in a patient with WPW syndrome?

Accepted Answer

Disappearance of the delta wave and normalization of the PR interval

Answer

Prolongation of the PR interval beyond 200 ms

Answer

Development of left bundle branch block morphology

Answer

Increase in QRS duration to greater than 160 ms

Question 3

A patient in the cardiac ICU develops ventricular fibrillation. After defibrillation and ROSC, which medication should be initiated to reduce recurrent VF?

Accepted Answer

IV amiodarone infusion

Answer

Oral flecainide 100 mg twice daily

Answer

IV digoxin 0.25 mg bolus

Answer

Sublingual nitroglycerin

Question 4

What is the significance of a prolonged QTc interval greater than 500 ms in a cardiac patient?

Accepted Answer

It markedly increases the risk of torsades de pointes

Answer

It indicates left ventricular hypertrophy

Answer

It confirms the diagnosis of Brugada syndrome

Answer

It is diagnostic of hyperkalemia

Question 5

A patient with sick sinus syndrome presents with symptomatic bradycardia alternating with episodes of supraventricular tachycardia. Which management approach best addresses both components of this condition?

Accepted Answer

Permanent pacemaker implantation with rate-controlling medications for tachyarrhythmia

Answer

Beta-blocker therapy alone to control tachyarrhythmias

Answer

IV atropine for long-term rate support

Answer

Catheter ablation of the AV node alone

Question 6

Which ECG feature differentiates Mobitz type II second-degree AV block from Mobitz type I?

Accepted Answer

Constant PR interval before a sudden dropped QRS in Mobitz II

Answer

Progressive PR shortening before a dropped beat in Mobitz II

Answer

Narrow QRS complexes exclusively in Mobitz II

Answer

Irregular PP intervals in Mobitz II

Question 7

Which class of antiarrhythmic drugs is most appropriate for long-term rate control in a patient with persistent atrial fibrillation and reduced left ventricular ejection fraction (EF 35%)?

Accepted Answer

Beta-blockers (carvedilol or metoprolol succinate)

Answer

Non-dihydropyridine calcium channel blockers (diltiazem)

Answer

Class IC agents (flecainide)

Answer

Class IA agents (quinidine)