Aims: Late after total correction, Fallot patients with a long 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-operatively 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.

Electrocardiography, Magnetic resonance imaging, Pulmonary valve replacement, Tetralogy of Fallot,
European Heart Journal
Department of Medical Informatics

Hooft Van Huysduynen, B, van Straten, A, Swenne, C.A, Maan, A.C, Ritsema van Eck, H.J, Schalij, M.J, … Vliegen, H.W. (2005). Reduction of QRS duration after pulmonary valve replacement in adult Fallot patients is related to reduction of right ventricular volume. European Heart Journal, 26(9), 928–932. doi:10.1093/eurheartj/ehi140