RIGHT-VENTRICULAR DYSPLASIA - THE MAYO-CLINIC EXPERIENCE

Objective: To determine the initial clinical manifestations and echoca rdiographic features of right ventricular dysplasia as encountered in a major cardiovascular referral center in the United States. Design: W e conducted a retrospective study of cases of right ventricular dyspla sia diagnosed at the Mayo Clinic between January 1978 and January 1993 . Material and Methods: In an institutional database search, we identi fied 20 patients with right ventricular dysplasia. Echocardiographic, electrophysiologic, Holter monitoring, cardiac catheterization, and en domyocardial biopsy results were analyzed. The mean duration of follow -up was 7 years. Results: In the 12 female and 8 male patients (mean a ge, 30 years; range, 3 to 60), the initial manifestations of right ven tricular dysplasia included ventricular arrhythmia (45%), congestive h eart failure (25%), heart murmur (10%), asymptomatic (10%), complete h eart block (5%), and sudden death (5%). First-order relatives were aff ected in 30% of the patients. Ventricular tachycardia with morphologic features of left bundle branch block was inducible in seven of nine p atients. On Holter monitoring, all but 2 of 15 patients studied had fr equent ventricular ectopic activity (Lown grade 2 or more). Characteri stic fatty infiltration of the myocardium was present in 7 of 13 right ventricular biopsy specimens. Inordinate right ventricular enlargemen t was present in 60% of the patients at first echocardiographic assess ment and in two other patients on follow-up assessment. Variable left ventricular involvement was noted in 50% of the cases. During the foll ow-up period, four patients died: two died suddenly, one died of conge stive heart failure, and one died of respiratory failure after a coron ary artery bypass operation. Of the 16 living patients, 8 are doing we ll, 3 have an implanted cardiac defibrillator, 3 are receiving antiarr hythmic agents, and 2 have undergone cardiac transplantation because o f progressive biventricular failure. Conclusion: Patients with right v entricular dysplasia have varied initial manifestations and a high fre quency of serious cardiovascular symptoms and complications.