CARDIAC SYNCOPE - BASKETBALL 1554

HISTORY - A 17 year-old varsity basketball player presented initially with an episode of severe weakness while playing basketball, lasting several minutes. The episode required him to stop playing. His pulse was found to be 50 bpm. He was subsequently examined by a physician but was asymptomatic at that time. One week later, he became weak, dizzy and flushed in the classroom. He was assisted to the health room where he experienced a true syncopal episode lasting about 60 seconds. He woke up diaphoretic and remained extremely fatigued for another 20 minutes. An EMT on the scene examined the player and described a “low” blood pressure and pulse of 52. He noted that he had been experiencing weak episodes especially immediately post exercise a with similar prodrome and post episode fatigue. The episodes were recurrent over the past several months and he could identify experiencing these episodes as early as 5 years old, usually associated with exercise. PHYSICAL EXAMINATION - Original examination demonstrated a well nourished adolescent. Wt. 147 BP 112/74 P 72 Ht. 70″ Arm span 72.5″ PERLA with lens intact. No carotid sinus sensitivity. Cardiac exam demonstrated a grade 1 murmur, possible mid-systolic click but without gallops. The murmur increased in intensity with upright posture. Lungs were clear. Thumb cross palmar sign was negative. Neurologic exam was normal. DIFFERENTIAL DIAGNOSIS: Hypertrophic Obstructive Cardiomopathy Vasovagal episode Anomolous Coronary Artery Marfans Syndrome Valvular Lesions - Aortic stenosis, Mitral valve prolapse, etc. Tachyarrhythmias - esp. Ventricular tachycardia, WPW, SVT Bradyarrhythmias - AV blocks, Sick sinus, etc. Congenital Long QT syndrome Non-cardiac causes - seizures, drugs, electrolytes, etc. TEST AND RESULTS: Routine chemistries and CBC: normal, Urine drug screen: negative, EKG: sinus rhythm, rate 61, QTc 459 ms., minimal ST depression. Stress test: normal but QTc 450 ms,2-D Echocardiogram: no definite mitral prolapse, mild mitral regurgitation, Holter Monitor: no dysrrhymias, Tilt table test: normal but upon adrenaline infusion QTc prolonged form 470 ms. pre-infusion to 600 ms. Post-infusion. FINAL/WORKING DIAGNOSIS: Congenital Long QT syndrome TREATMENT: Abstain from competitive sports Metoprolol 50 mg Bid