Endocardial Activation Mapping of Ventricular Tachycardia in Patients

Abstract

Background —Localization of early activated endocardial areas during ventricular tachycardia (VT) is mandatory for performance of surgical or radiofrequency catheter interventions. The use of a multielectrode catheter may shorten the procedure time and increase the accuracy of the procedure compared with single-electrode mapping techniques. This study was performed to evaluate the safety and efficacy of a 32-bipolar-electrode mapping catheter in patients. Methods and Results —The basket-shaped mapping catheter (BMC), integrated with a computerized mapping system, allowed on-line reconstruction of endocardial activation maps. Twenty patients with VT were studied before surgery (n=4) or radiofrequency catheter ablation (n=16). End-diastolic left ventricular (LV) volume was 280±120 mL, with an LV ejection fraction of 33±14%. The volume encompassed by the BMC was 164±27 mL (130 to 200 mL); the deployment time was 46±11 minutes. Endocardial activation time during sinus rhythm was 105±34 ms; 14±5 electrodes could be used to stimulate the heart. Cycle length of VT was 325±83 ms. Earliest endocardial activation was recorded 58±42 ms before the onset of the surface ECG. Complications were pericardial effusion (n=2) and transient cerebral disorientation (n=1). Conclusions —Percutaneous multielectrode endocardial mapping in patients with VT is feasible and relatively safe. The use of this technique shortens the time patients have to endure VT.