Arrhythmogenic right ventricular dysplasia: a generalized cardiomyopathy?

Arrhythmogenic right ventricular dysplasia (ARVD) is a recently described entity characterized by right ventricular myopathic changes and right ventricular tachycardia. The presence or extent of left ventricular dysfunction in ARVD is not known. We assessed right ventricular and left ventricular function and size in six patients with ARVD by echocardiography and radionuclide angiocardiography done in patients at rest and during exercise. All patients had recurrent ventricular tachycardia of left bundle branch block morphology, and right ventricular origin of the ventricular tachycardia was confirmed by endocardial mapping in four patients. The results were compared with those of 10 normal subjects and five patients with Wolff-Parkinson-White syndrome taking amiodarone. The latter group was a control group, since we did not withhold amiodarone therapy in four patients with ARVD. Mean ( + SD) right ventricular ejection fraction (EF) in patients with ARVD was 25 + 11% at rest and 26 12% during exercise. In normal subjects right ventricular EF was 51 + 4% at rest and 59 6% during exercise (p < .001). The right ventricular/left ventricular end-diastolic diameter ratio was 0.60 ± 0.24 in patients with ARVD and 0.37 ± 0.10 in normal subjects (p < .05). Right ventricular/left ventricular end-diastolic volume ratio was 2.41 + 1.05 in patients with ARVD and 1.16 ± 0.21 in normal subjects (p < .001). Measured in patients at rest, a subnormal left ventricular EF was present in two patients with ARVD but an abnormal left ventricular EF was present in all six patients during exercise. Mean left ventricular EF in patients with ARVD was 57 8% at rest and 55 10% during exercise (p > .05). In normal subjects, left ventricular EF was 61 + 4% at rest and 72 5% during exercise (p < .001). New left ventricular wall motion abnormalities were seen during exercise in all but one patient with ARVD. At rest and exercise, left ventricular and right ventricular EF in patients with Wolff-Parkinson-White syndrome were similar (p > .05) to those of normal subjects. We conclude that right ventricular dysfunction predominates in patients with ARVD but latent left ventricular dysfunction is present more often than is commonly recognized. These findings may have important diagnostic and therapeutic implications. Circulation 68, No. 2, 251-257, 1983. RIGHT VENTRICULAR DYSPLASIA is a pathologic condition in which the right ventricular myocardium is totally or partially replaced by fatty and fibrous tissue.' I The clinical expression of this condition may From the Cardiac Investigation Unit, University Hospital, Departments of Medicine and Surgery, University of Western Ontario, London, and the Cardiology Division, Department of Medicine, Foothills Hospital, and The University of Calgary, Calgary, Alberta. Supported in part by grants from the Ontario Heart Foundation, Toronto, and the Alberta Heart Foundation. Edmonton. Address for correspondence: Dante E. Manyari, M.D., Cardiology Division, The University of Calgary and Foothills Hospital, 1403 29th St., N.W., Calgary, Alberta, Canada T2N 2T9. Received Feb. 8, 1983; revision accepted April 14, 1983. Presented in part at the 55th Scientific Sessions of the American Heart Association, November 1982, Dallas. Vol. 68, No. 2, August 1983 depend on the extent of the pathologic changes. If involvement of the right ventricle is extensive, cardiomegaly and congestive cardiac failure may be present.'', ", 12 When dysplasia is limited to portions of the right ventricle, depression of cardiac function may be minimal or absent and clinically nonsignificant.3' '0 Patients may present with premature ventricular complexes or ventricular tachycardia of right ventricular origin independent of the extent of pathologic change and of the degree of diminished ventricular function." 2, 4, 8, 10, 13-21 When ventricular tachycardia is the principal manifestation, this condition is known as arrhythmogenic right ventricular dysplasia (ARVD). ARVD is recognized clinically by recurrent ventricular 251 by gest on N ovem er 6, 2017 http://ciajournals.org/ D ow nladed from