[Electrophysiologic and histopathologic investigations in children with idiopathic ventricular arrhythmias]

Between April 1984 and December 1987, electrophysiological studies and endomyocardial biopsy were performed in 14 pediatric patients, aged from 7 to 15 years, with idiopathic ventricular arrhythmias in whom diagnostic evaluation had revealed no structural heart disease. They were 8 boys and 6 girls. Cardiac catheterization revealed regional wall motion abnormalities of the left ventricle in 3 patients, one of whom showed decreased ejection fraction (EF). Electrophysiologic examination showed sinus node dysfunction in 21%. AV nodal dysfunction in 14% and dual AV nodal pathway in 21%. Histopathologic examination by endomyocardial biopsy showed myocellular hypertrophy, degeneration of myocytes, interstitial fibrosis and endomyocardial thickness in 86%, 36%, 35% and 14%, respectively. Since idiopathic ventricular arrhythmias in pediatric age group included relatively high electrophysiologic and histopathologic abnormalities, which were suggestive of occult myocardial disease and might be the early stage of cardiomyopathy, careful follow-up should be required.