Effects of pulmonary valve replacement on QRS duration and right ventricular cavity size late after repair of right ventricular outflow tract obstruction.

This study evaluated the effects of pulmonary valve replacement (PVR) on QRS duration and right ventricular (RV) cavity size in patients who had severe pulmonary regurgitation late after previous repair of RV outflow tract obstruction. A significant decrease in maximal QRS duration and RV end-diastolic volume was found after PVR. The change in QRS duration was most significant in patients with a baseline QRS > or =155 ms (176 +/- 15 to 160 +/- 18 ms, p <0.001). RV end-diastolic volume was significantly correlated with maximal QRS duration before (r = 0.93, p <0.0001) as well as after (r = 0.82, p <0.001) PVR. In patients with pulmonary regurgitation late after repair of RV outflow tract obstruction, PVR reduces maximal QRS duration with a concomitant decrease in RV volumes.