COMPARISON OF SINGLE-COIL AND DUAL-COIL ACTIVE PECTORAL DEFIBRILLATION LEAD SYSTEMS

Objectives. The purpose of this study was to compare defibrillation th resholds with lead systems consisting of an active left pectoral elect rode and either single or dual transvenous coils. Background. Lead sys tems that include an active pectoral pulse generator reduce defibrilla tion thresholds and permit transvenous defibrillation in nearly all pa tients. A further improvement in defibrillation efficacy is desirable to allow for smaller pulse generators with a reduced maximal output. M ethods. This prospective study was performed in 50 consecutive patient s. Each patient was evaluated with two lead configurations with the or der of testing randomized. Shocks were delivered between the right ven tricular coil and either an active can alone (single coil) or an activ e can with the proximal atrial coil (dual coil). The right ventricular coil was the cathode for the first phase of the biphasic defibrillati on waveform. Results. Delivered energy at the defibrillation threshold was 10.1 +/- 5.0 J for the single-coil configuration and 8.7 +/- 4.0 J for the dual-coil configuration (p < 0.02). Moreover, 98% of patient s had low (less than or equal to 15 J) thresholds with the dual-coil l ead system, compared with 88% of patients with the single-coil configu ration (p = 0.05). Leading edge voltage (p < 0.001) and shock impedanc e (p < 0.001) were also decreased with the dual coil configuration, al though peak current was increased (p < 0.001). Conclusions. A dual-coi l, active pectoral lead system reduces defibrillation energy requireme nts compared with a single-coil, unipolar configuration. (C) 1998 by t he American College of Cardiology.