Reduction of QRS duration after pulmonary valve replacement in adult Fallot patients is related to reduction of right ventricular volume

Aims Late after total correction, Fallot patients with a tong QRS duration are prone to serious arrhythmias and sudden cardiac death. Pulmonary regurgitation is a common cause of right ventricular (RV) failure and QRS lengthening. We studied the effects of pulmonary valve replacement (PVR) on QRS duration and RV volume. Methods and results Twenty-six consecutive Fallot patients were evaluated both pre-operativety and 6-12 months post-operatively by cardiac magnetic resonance (CMR). In this study, we present the computer-assisted analysis of the standard 12-lead electrocardiograms closest in time to the CMR studies. For the whole group, QRS duration shortened by 6 +/- 8 ms, from 151 +/- 30 to 144 +/- 29 ms (P = 0.002). QRS duration decreased in 18 of 26 patients by 10 +/- 6 ms, from 152 +/- 32 to 142 +/- 31 ms. QRS duration remained constant or increased slightly in eight of 26 patients by 3 +/- 3 ms, from 148 +/- 27 to 151 +/- 25 ms. CMR showed a decrease in RV end-diastolic volume from 305 +/- 87 to 210 +/- 62 mL (P = 0.000004). QRS duration changes correlated with RV end-diastolic volume changes (r = 0.54, P = 0.01). Conclusion Our study shows that PVR reduces QRS duration. The amount of QRS reduction is related to the success of the operation, as expressed by the reduction in RV end-diastolic volume.