[Echocardiographic study of the early repolarization syndrome. Demonstration of dynamic obstruction with isoprenaline. Apropos of 16 cases].

This study provides detailed information on the echocardiographic data obtained before and during an intravenous infusion of isoprenaline in a group of 16 patients under 50 years of age presenting with early repolarization syndrome and in a control group of 16 patients of the same age-group. The stereotyped echocardiographic features of early repolarization syndrome are described. They include: in the basal state, ventricular hyperkinesia, anterior motion of the mitral valve and reduction of the left ventricular outflow tract; these data were significant when compared with the control group; under isoprenaline, dynamic obstruction of the left ventricle. The authors discuss the electrical significance of the early repolarization syndrome, the relationship between that syndrome and the borderline forms of obstructive hypertrophic cardiomyopathy and the role of catecholamines in the pathogenesis of obstructive hypertrophic cardiomyopathy.