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

Adenosine is contraindicated in pre-excited atrial fibrillation with WPW because blocking the AV node can preferentially route conduction through the accessory pathway, potentially accelerating ventricular rate and precipitating ventricular fibrillation.

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

Successful ablation of the accessory pathway eliminates pre-excitation, resulting in disappearance of the delta wave and normalization of the PR interval as conduction now occurs exclusively through the AV node.

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

IV amiodarone is the standard pharmacologic agent used post-resuscitation to suppress recurrent ventricular fibrillation and maintain electrical stability while underlying causes are addressed.

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

A QTc greater than 500 ms represents significant prolongation of ventricular repolarization, substantially increasing the risk of torsades de pointes, a potentially fatal polymorphic ventricular tachycardia.

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

Tachy-brady syndrome (sick sinus syndrome) requires a permanent pacemaker to protect against symptomatic bradycardia while allowing safe use of rate-controlling or antiarrhythmic drugs to manage the tachyarrhythmic component.

CMC - Cardiac Medicine Certification Practice Test

CMC - Cardiac Medicine Certification Practice Test

CMC Cardiac Arrhythmia Management 3