10-Item USMLE Style MCQ Questionnaire on Stokes-Adams Attacks
Question 1
A 72-year-old man presents with recurrent episodes of sudden loss of consciousness with spontaneous recovery. His wife reports jerking movements during these episodes. ECG monitoring during an episode shows complete atrioventricular block with ventricular asystole lasting 8 seconds. What is the most appropriate definitive management?
A. Oral atropine therapy B. Oral isoproterenol therapy C. Permanent pacemaker implantation D. Implantable cardioverter-defibrillator E. Radiofrequency ablation
Answer: C. Permanent pacemaker implantation Permanent pacemaker implantation is the definitive treatment for Stokes-Adams attacks caused by AV block 1, 2.
Question 2
Which ECG finding is most characteristic of intrinsic disease of the His-Purkinje system as observed in Stokes-Adams attacks?
A. Progressive sinus bradycardia followed by sinus arrest B. Sudden-onset complete AV block with increasing sinus rate during the block C. Sinus tachycardia with ST-segment elevation D. Prolonged QT interval with torsades de pointes E. Atrial fibrillation with rapid ventricular response
Answer: B. Sudden-onset complete AV block with increasing sinus rate during the block This pattern is characteristic of intrinsic disease of the His-Purkinje system as observed in Stokes-Adams attacks 3.
Question 3
A 68-year-old woman with a history of Stokes-Adams attacks due to complete heart block has just received a permanent pacemaker. Which of the following pacing modes is most appropriate for this patient?
A. VVI (ventricular pacing, ventricular sensing, inhibited) B. AAI (atrial pacing, atrial sensing, inhibited) C. DDD (dual-chamber pacing, dual-chamber sensing, dual response) D. VOO (ventricular pacing, no sensing, no response) E. AOO (atrial pacing, no sensing, no response)
Answer: C. DDD (dual-chamber pacing, dual-chamber sensing, dual response) Dual-chamber pacing is preferred over single-chamber ventricular pacing to maintain AV synchrony and reduce risk of pacemaker syndrome 1, 2.
Question 4
During a Stokes-Adams attack with asystole, which pharmacologic agent is most appropriate as a temporary measure while preparing for transcutaneous pacing?
A. Amiodarone B. Atropine C. Digoxin D. Metoprolol E. Verapamil
Answer: B. Atropine For asystole or severe bradycardia, administering atropine 3 mg IV bolus is recommended as a temporary measure while preparing for transcutaneous pacing 1, 4.
Question 5
Which of the following arrhythmias is LEAST commonly associated with Stokes-Adams attacks?
A. Complete atrioventricular block B. Sinoatrial block C. Ventricular fibrillation D. Atrial fibrillation with rapid ventricular response E. Paroxysmal ventricular asystole
Answer: D. Atrial fibrillation with rapid ventricular response Stokes-Adams attacks are most commonly related to AV block (50-60%), SA block (30-40%), and less commonly to ventricular tachyarrhythmias (0-5%). Atrial fibrillation with rapid ventricular response is not typically associated with Stokes-Adams attacks 2.
Question 6
A 65-year-old man with a history of Stokes-Adams attacks has been diagnosed with tachycardia-bradycardia syndrome. In addition to pacemaker implantation, what additional therapy should be considered?
A. Beta-blocker therapy only B. Calcium channel blocker therapy only C. Anti-arrhythmic drug therapy D. Anticoagulation therapy only E. Anti-arrhythmic drug therapy and anticoagulation
Answer: E. Anti-arrhythmic drug therapy and anticoagulation Most patients with tachycardia/bradycardia syndromes require supplementary anti-arrhythmic treatment, and in some patients additional long-term anticoagulation should be considered 2.
Question 7
A 4-year-old child presents with sudden loss of consciousness and seizure-like activity. ECG shows complete heart block with QRS complexes demonstrating right bundle branch block with left posterior hemiblock pattern. What is the most likely diagnosis?
A. Congenital complete heart block B. Acute nonspecific myocarditis C. Long QT syndrome D. Hypertrophic cardiomyopathy E. Tetralogy of Fallot
Answer: B. Acute nonspecific myocarditis In children, acute nonspecific myocarditis can present with Stokes-Adams attacks and complete heart block with QRS complexes showing right bundle branch block with left posterior hemiblock pattern 5.
Question 8
Which diagnostic test is most appropriate when ECG monitoring fails to capture the arrhythmia responsible for suspected Stokes-Adams attacks in a patient with bundle branch block?
A. Exercise stress test B. Echocardiography C. Cardiac MRI D. Electrophysiologic study with His bundle electrography E. Coronary angiography
Answer: D. Electrophysiologic study with His bundle electrography When ECG monitoring leaves doubt, an electrophysiologic study including His bundle electrography may support the diagnosis of Stokes-Adams attacks 1, 2.
Question 9
A 23-month-old child with congenital complete heart block experiences a Stokes-Adams attack. ECG shows an intermittently prolonged QT interval. What additional arrhythmia should be suspected as the cause of the attack?
A. Sinus bradycardia B. Ventricular tachycardia C. Atrial fibrillation D. Junctional escape rhythm E. Second-degree AV block
Answer: B. Ventricular tachycardia The combination of congenital complete heart block and a prolonged QT interval carries a significant risk of ventricular tachycardia, which can precipitate Stokes-Adams attacks 6.
Question 10
During a witnessed Stokes-Adams attack with ventricular fibrillation in a monitored setting, what is the most appropriate immediate intervention?
A. Precordial thump followed by defibrillation B. Immediate defibrillation C. Atropine administration D. Transcutaneous pacing E. Cardiopulmonary resuscitation only
Answer: B. Immediate defibrillation For witnessed monitored arrest with ventricular tachyarrhythmias, defibrillation is the preferred immediate intervention 1.