Endocardial Activation Mapping of Ventricular Tachycardia in Patients

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.