OUTCOME OF ARRHYTHMOGENIC RIGHT-VENTRICUL AR DYSPLASIA

The authors propose a classification of the outcome of arrhythmogenic right ventricular dysplasia with reference to 4 selected cases with a follow-up period of over 9 years. In type I, the left ventricular ejec tion fraction is normal (EF > 50 %) and the risk, exclusively arrhythm ic, can be controlled by appropriate antiarrhythmic therapy. This is t he commonest form of arrhythmogenic right ventricular dysplasia with d ifferent varieties according to the degree of dilatation of the right ventricle. In type II, there is a variable degree of left ventricular involvement (30 < EF < 50 %) either by extension of a comparable disea se process as observed in the right ventricle or by an isolated or sup erimposed phenomenon of myocarditis. This form is stable and may remai n stable for many years providing the arrhythmias are correctly treate d. In type III, progressive degradation of the myocardium is observed over a period of about 10 years with a clinical presentation comparabl e to that of certain arrhythmogenic dilated cardiomyopathies which are often hereditary. In this case, the patients have an arrhythmic risk associated with that of cardiac failure which becomes progressively ir reversible. The histology shows interstitial fibrosis with biventricul ar lymphocytic infiltration suggesting an autoimmune phenomenon. There fore, the classification of cases of arrhythmogenic right ventricular dysplasia depends on the potential evolutivity of the lesions. When th e patient is seen in the early stages of the disease, the prognosis sh ould be garded, especially in a hereditary form.