Ventricular fibrillation in six adults without overt heart disease

Findings are described in six patients with no clinical evidence of heart disease who had documented ventricular fibrillation (five patients) or ventricular flutter (one patient). The mean age of the six patients, all men, was 34 years (range 26 to 43). Cardiovascular collapse occurred in all and was followed by successful cardioversion. No patient had electrolyte or QT abnormalities. One patient had slight right ventricular enlargement on M-mode echocardiography, and another had a left ventricular pressure gradient at rest of 30 mm Hg with a normal two-dimensional echocardiogram. Holter electrocardiographic monitoring revealed incessant ventricular tachycardia in one patient and nonsustained ventricular tachycardia in three others. Exercise testing revealed nonsustained ventricular tachycardia in one patient. Ventricular fibrillation was induced at the time of programmed electrical stimulation in four of the six patients. Documented recurrence of ventricular fibrillation or ventricular flutter occurred in three patients, but in only one patient receiving antiarrhythmic drugs. Four patients were treated with amiodarone and one received an automatic implantable cardioverter-defibrillator. All patients are alive after a mean follow-up period of 78 months after the first documentation of their arrhythmia and 37 months after programmed electrical stimulation. Ventricular fibrillation can occur in the apparently structurally normal human heart. Antiarrhythmic treatment can provide effective control of this malignant arrhythmia.