AMBULATORY MONITORING OF THE SUDDEN-DEATH OF AN ADOLESCENT WITH HYPERTROPHIC CARDIOMYOPATHY

Sudden death is an important cause of mortality in hypertrophic cardio myopathy. Several mechanisms have been proposed, but ambulatory monito ring of the event has rarely occurred. The case of an adolescent girl with congenital hypertrophic cardiomyopathy and arthrogryposis mutiple x congenita is presented. Despite appropriate therapy and severe activ ity limitation, the patient's condition progressively worsened. The pa tient died suddenly in her sleep, one month after a myocardial myomect omy for subaortic stenosis. The fortuitous ambulatory electrocardiogra phic (ECG) monitoring of the event recorded polymorphic ventricular ta chycardia degrading into ventricular fibrillation. Retrospective revie w of previous ambulatory ECG revealed the presence of nonsustained ven tricular tachycardia, a predictive determinant for sudden death, and a trioventricular node dysfunction. However, the patient had never repor ted symptoms during the dysrhythmias. The pathological specimen showed an unexpected old apical infarction scar, suggesting that her preoper ative cardiac status was worse than suspected. In summary, the mechani sm of sudden death in this patient was revealed by ambulatory ECG moni toring, and the involvement of neural and myocardial factors are propo sed.