COMPARISON OF EFFECTIVE AND INEFFECTIVE TARGET SITES THAT DEMONSTRATECONCEALED ENTRAINMENT IN PATIENTS WITH CORONARY-ARTERY DISEASE UNDERGOING RADIOFREQUENCY ABLATION OF VENTRICULAR-TACHYCARDIA

Background Concealed entrainment has been useful in guiding catheter a blation of monomorphic ventricular tachycardia in patients with corona ry artery disease. However, not all sites with concealed entrainment r esult in successful ablation of the targeted ventricular tachycardia. The purpose of this prospective study was to identify factors at sites that demonstrate concealed entrainment that differentiate effective f rom ineffective target sites. Methods and Results In 14 consecutive pa tients with hemodynamically stable monomorphic ventricular tachycardia and coronary artery disease, radiofrequency ablation of 26 ventricula r tachycardias was performed. Ablation was attempted at 46 sites that demonstrated concealed entrainment. Twenty-five of the targeted ventri cular tachycardias (96%) were successfully ablated. The positive predi ctive value of concealed entrainment for successful ablation was 54%; it increased to 72% in the presence of a stimulus-QRS interval/ventric ular tachycardia cycle length ratio of less than or equal to 70%, to 8 2% in the presence of a match of the stimulus-QRS and electrogram-QRS interval, and to 89% in the presence of isolated middiastolic potentia ls that could not be dissociated from ventricular tachycardia during e ntrainment. Conclusions The positive predictive value of concealed ent rainment for identification of successful ablation sites in patients w ith sustained ventricular tachycardia and coronary artery disease can be significantly enhanced by the presence of associated mapping criter ia, particularly an isolated mid diastolic potential that cannot be di ssociated from the tachycardia.