A 36-year-old man comes to the emergency department due to loss of consciousness. He was standing in a crowded subway station when he felt lightheaded, had a pounding sensation in his chest, and passed out. On awakening, he felt short of breath for a little while and then was "completely fine." He has had no similar episodes, nor chest pain, confusion, tongue biting, or urinary incontinence. The night before, he was at a party with friends and consumed alcohol. Later he was nauseated and had 3 episodes of vomiting and one episode of diarrhea. In the emergency department, blood pressure is 124/68 mm Hg and pulse is 80/min. There is a small laceration above his right eyebrow. Cardiac examination shows normal heart sounds with regular rhythm. The lungs are clear to auscultation. Neurologic examination shows no abnormalities. ECG is shown in the exhibit. The patient is hospitalized for observation. His serum electrolytes are within normal limits. Echocardiogram shows normal left ventricular size and function and no significant valvular abnormalities. During the hospital stay, he has another episode of lightheadedness when the telemetry revealed brief supraventricular tachycardia that resolved spontaneously. Which of the following is the most appropriate next step in management?

Question

A 36-year-old man comes to the emergency department due to loss of consciousness.  He was standing in a crowded subway station when he felt lightheaded, had a pounding sensation in his chest, and passed out.  On awakening, he felt short of breath for a little while and then was "completely fine."  He has had no similar episodes, nor chest pain, confusion, tongue biting, or urinary incontinence.  The night before, he was at a party with friends and consumed alcohol.  Later he was nauseated and had 3 episodes of vomiting and one episode of diarrhea.  In the emergency department, blood pressure is 124/68 mm Hg and pulse is 80/min.  There is a small laceration above his right eyebrow.  Cardiac examination shows normal heart sounds with regular rhythm.  The lungs are clear to auscultation.  Neurologic examination shows no abnormalities.  ECG is shown in the exhibit. The patient is hospitalized for observation.  His serum electrolytes are within normal limits.  Echocardiogram shows normal left ventricular size and function and no significant valvular abnormalities.  During the hospital stay, he has another episode of lightheadedness when the telemetry revealed brief supraventricular tachycardia that resolved spontaneously.  Which of the following is the most appropriate next step in management?

Quizplus · Accepted Answer

Explanation: The overall incidence of sudden cardiac death in patients with Wolff-Parkinson-White (WPW) pattern on ECG is low (<1%), but the risk is significantly increased in patients with episodes of tachyarrhythmia. Tachyarrhythmia due to atrial fibrillation is especially dangerous because impulses can conduct from the atria to the ventricles at a very fast rate, potentially causing rhythmic degeneration to ventricular fibrillation. This patient with WPW pattern on ECG, recent syncope event, and documented supraventricular tachycardia with associated symptoms meets criteria for WPW syndrome, and definitive therapy is indicated. Catheter ablation is the recommended therapy in patients with WPW syndrome. It has a nearly 90% efficacy rate and <5% risk of complications, replacing surgical ablation as the preferred treatment for accessory pathways. The need for catheter ablation in asymptomatic patients with WPW pattern on ECG is controversial; ablation is sometimes favored in young patients, but observation is often favored in older patients who have demonstrated a relatively longer symptom-free period. (Choice B) Coronary angiography is an invasive procedure indicated for management of acute coronary syndrome. This patient does not have findings to suggest acute coronary syndrome and would be better managed with catheter ablation therapy. (Choice C) A loop event recorder allows ambulatory ECG monitoring when patients have symptoms (eg, palpitations, lightheadedness) that are suspected to be the result of paroxysmal arrhythmia. However, additional diagnostic cardiac monitoring is not needed in this patient as the resting ECG findings combined with documentation of symptomatic supraventricular tachycardia on telemetry are diagnostic of WPW syndrome. (Choice D) Nuclear stress testing can be used for diagnosis of coronary artery disease but has no role in managing patients with WPW syndrome. (Choice E) Tilt-table testing can be used in the evaluation of recurrent syncope (particularly vasovagal syncope) and is reserved for patients who have been ruled out for heart disease (structural or conductive). This patient has conductive evidence of WPW and would not benefit from a tilt-table test. Educational objective: Patients with Wolff-Parkinson-White syndrome are at risk of sudden cardiac death because the accessory pathway can lead to atrial fibrillation that can degenerate into ventricular fibrillation. Catheter ablation to obliterate the accessory pathway is the preferred treatment. References: ACC/AHA/ESC guidelines for the management of patients with supraventricular arrhythmias--executive summary: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and the European Society of Cardiology Committee for Practice Guidelines (Writing Committee to Develop Guidelines for the Management of Patients With Supraventricular Arrhythmias). (http://www.ncbi.nlm.nih.gov/pubmed/14557344)

A 36-Year-Old Man Comes to the Emergency Department Due to Loss