SIMULTANEOUS 60-ELECTRODE MAPPING OF VENTRICULAR-TACHYCARDIA USING PERCUTANEOUS CATHETERS

Objectives. We developed a new approach for mapping ventricular tachyc ardia at electrophysiologic study using simultaneous recordings from u p to 60 catheter electrodes. Background. Good results for surgical or catheter ablation of ventricular tachycardia are limited by the abilit y to detect and completely map all of the underlying arrhythmogenic ar eas. Currently, catheter mapping of all configurations of ventricular tachycardia is impossible or unsatisfactory in at least 60% of patient s because of poorly tolerated rapid rates, nonsustained ventricular ta chycardia or multiple configurations. Methods. Twenty-four patients wi th recurrent ventricular tachycardia refractory to antiarrhythmic drug s were studied using up to six percutaneous decapolar catheters introd uced into the ventricles. Left ventricular maps of ventricular tachyca rdia were achieved by two to three transseptal catheters, two to three transaortic catheters, a coronary sinus catheter and right ventricula r catheters. Simultaneous endocardial maps of either right or left ven tricles were possible with a resolution of similar to 1 to 2 cm. Up to 60 electrograms were digitized and recorded simultaneously using a cu stom computerized mapping system. Results. Successful maps of 73 ventr icular tachycardia configurations were obtained in 22 patients. The ma pping procedure failed in two patients because of inability to cathete rize the left ventricle in one and inability to induce monomorphic ven tricular tachycardia in the other. The mean (+/-SD) ventricular tachyc ardia cycle length was 285 +/- 53 ms (range 215 to 470). A total of 39 separate arrhythmogenic areas (median 1, interquartile [25% to 75%] r ange 1 to 3/patient) were detected, of which 21 (54%) were in the left ventricular free wall, 17 (44%) were in the ventricular septum, and 1 (2%) was in the right ventricular outflow tract. Ten patients (45%) h ad at least two arrhythmogenic areas. Thirteen patients subsequently u nderwent operation. All but one of the arrhythmogenic areas found at s urgical mapping had been identified at preoperative catheter mapping. Complications of the preoperative mapping procedure occurred in four p atients, with complete resolution in three and minor long term sequela e in the other. Conclusions. This technique permits detailed catheter mapping of all types of monomorphic ventricular tachycardias, includin g those leading to hemodynamic collapse, and should enable better choi ce and direction of surgical or catheter ablation.