Arrhythmogenic right ventricular dysplasia as a cause of "sudden cardiac death" with survival

History: A 42 year old woman was resuscitated from ventricular fibrillation. 5 months previously she had a syncope. Her nephew had died of sudden cardiac death at the age of 25 years. Investigations: There was no evidence for ST segment elevation, myocardial infarction or pulmonary embolism. The ECG showed right precordial T wave inversion. Coronary artery disease was excluded angiographically. Echocardiography and angiography revealed inferior wall akinesia of the right ventricle with normal left ventricular function and chamber size. Ventricular fibrillation could not be reproduced by programmed stimulation of the right ventricle during an electrophysiologic study. Results of endomyocardial biopsy of the right ventricle showed a focal fibrous infiltration of the myocardium. Magnetic resonance imaging confirmed inferior wall abnormalities of the right ventricle without typical fatty infiltration in the right ventricular myocardium. Clinical course: The patient recovered rapidly without neurologic deficits. Arrhythmogenic right ventricular dysplasia was suspected, and a cardioverter defibrillator (ICD) was implanted. Within 6 months after implantation the ICD memory showed no evidence of ventricular fibrillation. Conclusion: Arrhythmogenic right ventricular dysplasia is an important cause of ventricular fibrillation with a potential risk of sudden cardiac death in young persons. Concealed arrhythmogenesis as an early manifestation of right ventricular dysplasia is difficult to detect.