Ventricular premature contraction after repair of tetralogy of Fallot--the influence of postoperative factors, particularly the right ventricular regional wall motion.

The presence and severity of ventricular premature contraction (VPC) in 35 patients with tetralogy of Fallot (TF) were studied, 5 to 10 years after intracardiac repair (ICR), using treadmill exercise testing and 24-hour ambulatory monitoring. VPCs were observed in 24 patients (68.6%). The patients were classified into two groups according to the types of VPCs: group A (23 patients) without VPCs or with VPCs of Lown's grade 1 and group B (12 patients) with VPCs of Lown's grade 2, 3 or 4. Group B patients were found to have significantly higher right to left ventricular peak-systolic pressure ratios and higher right ventricular peak systolic pressures than those of group A. But there were no significant differences between the two groups in operative age, the time lapse between ICR and evaluation, the duration of exercise and so on. Group B patients also showed significantly decreased right ventricular regional wall motions in the right ventricular outflow tracts (ROTs), indicating akinetic or paradoxical movements than group A patients. It is thought that postoperative right ventricular hypertension and the akinetic or paradoxical wall movement of the ROT may have some effect on the genesis of postoperative VPCs after repair of TF.