Histopathologic aspects of endomyocardial biopsy in pediatric patients with idiopathic ventricular tachycardia

Purpose: The present study aimed to investigate the clinicopathologic findi ngs and histopathologic characteristics of endomyocardial biopsy in pediatr ic patients with idiopathic ventricular tachycardia. Methods: Histopathological findings of endomyocardial biopsy from 17 patien ts aged 7-15 years with idiopathic ventricular tachycardia (VT) but no orga nic heart disease were examined. Patients considered to have cardiomyopathy of the dilated, hypertrophic or specific form or arrhythmogenic right vent ricular cardiomyopathy were excluded from this study. Results: Advanced histopathologic findings, including myocyte hypertrophy, degeneration, interstitial fibrosis and disarrangement of muscle bundles, w ere disclosed in three cases (17.6%). One of these cases exhibited sustaine d VT with left bundle branch block configuration and showed increased frequ ency of VT during exercise testing. The remaining two cases had non-sustain ed VT with multifocal origin and had syncope episodes. Another 14 cases sho wed mild or no significant findings in the biopsy. Conclusions: These results indicate that advanced histopathology in endomyo cardial biopsy is occasionally disclosed in cases of idiopathic VT, especia lly those of exercise-related VT or multifocal VT, and that these patients may be considered as having heart muscle disease.