Comparison of endocardial activation times at effective and ineffective ablation sites within the pulmonary veins

Pulmonary Vein Arrhythmias. Introduction: Recent studies demonstrated that atrial arrhythmias may be generated within pulmonary veins, The purpose of this study was to compare the endocardial activation times at effective and ineffective ablation sites during radiofrequency catheter ablation of arrh ythmias initiated or generated within pulmonary veins. Methods and Results: Twenty-one of 28 patients without structural heart dis ease underwent successful ablation of 23 arrhythmogenic foci within a pulmo nary vein. Electrograms were recorded at 75 pulmonary venous sites and cate gorized into three groups: 23 successful ablation sites; 28 unsuccessful ta rget sites within an arrhythmogenic pulmonary vein; and 24 sites within non arrhythmogenic pulmonary veins. The endocardial activation time of prematur e depolarizations arising at successful target sites was significantly earl ier than at other sites. During premature depolarizations, an endocardial a ctivation time of -75 msec or earlier had a sensitivity of 83% and a specif icity of 79% for identification of a successful ablation site. Endocardial activation times earlier than -100 msec were recorded only at successful ab lation sites, and endocardial activation times later than -30 msec were rec orded only at sites within nonarrhythmogenic pulmonary veins. The presence of a split potential during sinus rhythm or premature depolarizations was n ot a specific indicator of a successful ablation site. Conclusion: The endocardial activation times of premature depolarizations t hat arise within pulmonary veins and initiate atrial tachycardia/fibrillati on are useful in identifying successful ablation sites.