Electrocardiographic Abnormalities Occurring After Radiofrequency Catheter Ablation of Manifest Accessory Pathways in the Wolff-Parkinson-White Syndrome

Electrical abnormalities such as negative and abnormally tall-peaked T waves are seen in ECGS after radiofrequency (RF) catheter ablation of manifest accessory pathways in the WolffParkinson- White syndrome. The aim of the study was to evaluate the ECG changes which occurred after manifest and concealed accessory pathway ablation in patients with WPW syndrome and ablation of slow pathway in atrioventricular (AV) nodal reentrant tachycardia. Twenty-five patients with manifest accessory pathway were included in group 1, and 12 patients with concealed accessory AV connection plus 15 patients having AV nodal modification were included in group 2. Successful RF ablation was achieved in all patients ECG samples were recorded before ablation, after 2 hours and after 5 weeks T wave changes, T wave axes, QRS-T angle, numbers of ablation lesions and peak creatin kinase (CK-MB) values were compared between the two groups. Repolarisation abnormalities were seen in 24 of 25 patients (%96) with manifest accessory pathways. There were no repolarisation abnormalities in group 2 (p<0.001). Abnomal T wave axis, QRS-T angle and repolarisation abnormalities returned to normal in group 1. These parameters did not change in group 2. The pre-excited QRS duration was significantly longer in patients having repolarisation abnormalities after RF ablation. Because of the numbers of ablation lesions and peak CK-MB values were not significantly different between the two groups, we considered that repolarisation abnormalities were not a result of myocardial injury. According to the "T wave memory" which had been conupt was proposed to describe the mechanism of repolarisation abnormalities, the, myocardium can remember its normal repolarisation pattern after establishing. Normal depolarisation cascade in patients with WPW. We conclude that this phenomenon may also be the cause of repolarisation abnormalities that occurred in our patients with WPN syndisul.