[Evaluation of the arrhythmogenic potential of myocardiopathy. Apropos of 113 cases].

The exploration of 113 cases of myocardiopathy (69 cases of dilated myocardiopathy (DMC) and 44 of hypertrophic myocardiopathy (HMC) by a 24-hour Holter recording, exercise tests, recording of surface-delayed ventricular potentials (DVPs) and forced right ventricular stimulation (PVS), revealed an arrhythmogenic potential in both forms of this disorder. In cases of DMC, ventricular arrhythmias were common (81% of cases), frequently recurrent and may constitute one sign of the disease, although they are fairly independent of hemodynamic changes. The presence of DVPs in cases of DMC (25% of cases) was significantly correlated with ventricular extra-systole greater than or equal to grade 3 on the lown scale revealed by the Holter with induction of tachycardia or ventricular fibrillation in response to PVS. Ventricular arrhythmia is less common in HMC (57%). DVPs were rare, and spontaneous or induced ventricular arrhythmia appeared to be more closely correlated with syncope than with any other hemodynamic factor. This study of the arrhythmogenic potential therefore appears to be necessary in myocardiopathy in order to obtain a better definition of the prognostic risk.