[Complex ventricular arrhythmia in apparently healthy young subjects].

The aim of this study of 20 young subjects (28 +/- 10.6 years) with no apparent cardiac disease on clinical examination and chest X-ray was to determine the origin of complex ventricular arrhythmias: monomorphic or polymorphic ventricular extrasystoles, isolated or in valves (average 18 158 +/- 12 388 per 24 hours) and/or ventricular tachycardia (5 cases, sustained in 3). These arrhythmias were aggravated (N = 6), disappeared (N = 8) or remained unchanged (N = 5) during exercise. The inter-critical ECG showed ST changes in 5 cases. The extrasystoles had a left bundle branch block configuration in 14 cases and a right bundle branch block configuration in 9 cases. Nine patients were Grade 2 (45%) and 11 patients Grade 4B of Lown's classification. Complementary investigations (echocardiography), radionuclide investigations, right and left heart catheterisation, selective right and left ventriculography and coronary angiography) showed a high incidence of arrhythmogenic right ventricular dysplasia (N - 14) associated with left ventricular abnormalities in 13 cases: hypofixation of Thallium (N = 14) associated with left ventricular abnormalities in 13 cases: hypofixation of Thallium (N = 11), abnormal global left ventricular function (N = 13) with decreased ejection fractions in half the cases, left ventricular dilatation in a third of cases (average and diastolic volume: 109.8 ml/m2), mean velocity of circumferential fibre shortening decreased in 86% of cases (average 0.88 cir/sec), angiographic abnormalities of segmental left ventricular wall motion in 36% of cases; 2 clinically silent cases of mitral valve prolapse were associated with these left ventricular changes; these cases represent forms of arrhythmogenic cardiac disease localised to the right ventricle or involving both ventricles which should be searched for routinely in young patients with apparently normal hearts but with idiopathic and severe ventricular arrhythmias. The diagnosis can only be established by angiography. In other cases, isolated left ventricular abnormalities are detected: two cases of hypertrophic non obstructive cardiomyopathy including one apical form, a condition which may be suspected from analysis of the surface ECG and careful 2D echocardiographic study; phonomechanography may be normal; one idiopathic left ventricular aneurysm which was only diagnosed at ventriculography; one dilated cardiomyopathy affecting the left ventricle. In our series, none of the patients had coronary artery disease and two patients even had no abnormality of any of these investigations.(ABSTRACT TRUNCATED AT 400 WORDS)