Aborted Sudden Cardiac Death During Sport Participation Resulting From Non-obstructive Hypertrophic Cardiomyopathy

Abstract

HISTORY: A 16 year-old male student collapsed during a recreational basketball game at his high school. There was no evidence of trauma. This was a witnessed arrest and he immediately received bystander CPR; a school-based automatic external defibrillator (AED) was applied and employed within 2 minutes. The AED advised shock for ventricular fibrillation, and appropriate therapy was delivered. Following intubation, the student remained hypotensive and was transferred to a medical facility for intensive cardiac care monitoring and management. PHYSICAL EXAMINATION: Examination in the hospital demonstrated a tall, skinny youth with long arms and legs; arm span was less than leg span. Neither arachnodactyly nor pectus excavatum were present. Cardiac exam demonstrated a regular rhythm without murmurs. Pulses were equal and strong throughout all extremities. DIFFERENTIAL DIAGNOSIS: Hypertrophic Obstructive Cardiomyopathy (HOCM) Anomalous Coronary Artery Arrhythmogenic right ventricular cardiomyopathy Marfan syndrome with aortic rupture Brugada syndrome Long QT Syndrome Catecholaminergic polymorphic ventricular tachycardia Wolff-Parkinson-White syndrome TEST AND RESULTS: ECG: Sinus rhythm with left atrial enlargement. There was profound QRS voltage (R wave in V4 70 mm/7mV) suggestive of hypertrophy and marked precordial ST-T wave changes. Normal QT interval. No delta or epsilon wave. Echocardiogram: Asymmetric septal hypertrophy: interventricular septum (18 mm), posterior septum (10 mm); no systolic anterior motion of the mitral valve; no resting or inducible left ventricular outflow tract obstruction. Normal right ventricle, normal aortic root. FINAL WORKING DIAGNOSIS: Ventricular Fibrillation incited by Hypertrophic Non-obstructive Cardiomyopathy TREATMENT AND OUTCOMES: 1. Hemodynamic and respiratory stabilization 2. Beta-blocker therapy 3. Secondary Prevention: Implanted Cardiac Defibrillator 4. Screening of potentially effected family members (given propensity for autosomal dominant inheritance) 5. Sports proscription