Two-coil versus single-coil transvenous cardioverter defibrillator systems: Comparative data

Two types of new-generation transvenous implantable cardioverter defibrilla tor (ICD) systems, incorporating a two-coil (62 patients, group 1) versus s ingle-coil (32 patients, group 2) lead system were compared among 94 consec utive patients. The two groups were comparable in age (58 +/- 13 vs 59 +/- 14 years), presenting arrhythmia (ventricular tachycardia versus ventricula r fibrillation 77%/21% vs 84%/13%), cycle length of induced VT (294 +/- 4 v s 289 +/- 44 ms), number of unsuccessful antiarrhythmic drugs (1.7 +/- 0.8 vs 1.7 +/- 0.7), and left ventricular ejection fraction (35 +/- 12% vs 34 /- 9%). Both systems were successfully implanted strictly transvenously in all patients. Biphasic shocks were used in all patients. Active shell devic es were used in 79% and 84% patients of groups I and II, respectively (P = NS). Intraoperative testing revealed comparable defibrillation threshold (D FT) values (10.2 +/- 3.7 J in group 1 versus 9.3 +/- 3.6 J in group 2 syste m), and pacing threshold (0.7 +/- 0.3 vs 0.7 +/- 0.3 V), but R wave amplitu de and lead impedance were lower in group 1 (13 +/- 5 vs 16 +/- 5 mV P = 0. 003; and 579 +/- 115 vs 657 +/- 111 ohms, P = 0.002, respectively). Lead in sulation break requiring reoperation occurred in one patient with an Endota k lead, and two patients with Transvene leads had initially high DFT with a single one-lead/active can system, which was converted to a two- or three- endocardial-lead/inactive can configuration. We conclude that both single-c oil and two-coil transvenous ICD systems were associated with high rates of successful strictly transvenous ICD implantation and a low incidence of le ad-related complications. Significant differences were noted in the sensed R wave and lead impedance, probably reflecting the active fixation characte ristics of the Transvene lead. However, in order to obviate the sporadic ne ed for implantation of additional endocardial leads, as was the case in two patients in this series, a double-coil lead may be preferable.