Comparison of vectorcardiographic and 12-lead electrocardiographic detections of abnormalities in repolarization properties due to preexcitation in patients with Wolff-Parkinson-White syndrome - Proposal of a novel concept of a "remodeling gradient"

Repolarization abnormalities after radiofrequency ablation in patients with manifest Wolff-Parkinson-White syndrome (WPW) have been attributed to card iac memory of preexisting changes in repolarization properties. We compared spatial ventricular gradient (VG) from vectorcardiograms with QRST values of 12-lead ECG in 41 patients with WPW (group A, manifest WPW due to left-s ided accessory pathway (n = 20); group B, manifest WPW due to right-sided a ccessory pathway (n = 12); group C, concealed WPW (n = 9)) before and after ablation. Group N (n = 607) served as control. In groups A and B, the abno rmalities of spatial VG and QRST values of 12-lead ECG that existed before and 1 day after ablation significantly decreased 1 week after ablation. In group C, spatial VG and QRST values of 12-lead ECG showed no significant ch anges. The diagnostic ability of spatial VG is almost equivalent to that of the QRST value of ECG in detecting repolarization abnormalities in patient s with WPW before and after ablation. We propose a new concept of a "remode ling gradient" directing from the preexcited area to the opposite side of t he ventricle as a result of preexcitation-induced electrical remodeling.