Endomyocardial biopsy approach in cases with ventricular arrhythmias.

Right ventricular endomyocardial biopsies were performed in patients with ventricular tachycardia (VT: n = 20) and idiopathic premature ventricular contraction (PVC: n = 23). Active myocarditis was found in one case and postmyocarditic change in 9 cases. Significant pathology according to our definition was found in 9 out of the total of 43 cases (20.5%). The pathological features of the 9 cases were interstitial fibrosis in 5, disarrangement of muscle bundles in 6, degeneration of myocytes in one and increase in fatty tissue in 7. Increase in fatty tissue was characteristically observed in 6 out of the 20 cases with VT and it was noteworthy that the VT cases with left bundle branch block configuration showed high incidence of the fatty tissue (5/12 cases, 42%).