RIGHT-VENTRICULAR DYSPLASIA - THE MAYO-CLINIC EXPERIENCE

Objective: To determine the initial clinical manifestations and echocardiographic features of right ventricular dysplasia as encountered in a major cardiovascular referral center in the United States. Design: We conducted a retrospective study of cases of right ventricular dysplasia diagnosed at the Mayo Clinic between January 1978 and January 1993. Material and Methods: In an institutional database search, we identified 20 patients with right ventricular dysplasia. Echocardiographic, electrophysiologic, Holter monitoring, cardiac catheterization, and endomyocardial biopsy results were analyzed. The mean duration of follow-up was 7 years. Results: In the 12 female and 8 male patients (mean age, 30 years; range, 3 to 60), the initial manifestations of right ventricular dysplasia included ventricular arrhythmia (45%), congestive heart failure (25%), heart murmur (10%), asymptomatic (10%), complete heart block (5%), and sudden death (5%). First-order relatives were affected in 30% of the patients. Ventricular tachycardia with morphologic features of left bundle branch block was inducible in seven of nine patients. On Holter monitoring, all but 2 of 15 patients studied had frequent ventricular ectopic activity (Lown grade 2 or more). Characteristic fatty infiltration of the myocardium was present in 7 of 13 right ventricular biopsy specimens. Inordinate right ventricular enlargement was present in 60% of the patients at first echocardiographic assessment and in two other patients on follow-up assessment. Variable left ventricular involvement was noted in 50% of the cases. During the follow-up period, four patients died: two died suddenly, one died of congestive heart failure, and one died of respiratory failure after a coronary artery bypass operation. Of the 16 living patients, 8 are doing well, 3 have an implanted cardiac defibrillator, 3 are receiving antiarrhythmic agents, and 2 have undergone cardiac transplantation because of progressive biventricular failure. Conclusion: Patients with right ventricular dysplasia have varied initial manifestations and a high frequency of serious cardiovascular symptoms and complications.