title: A long thin electrode is equivalent to a short thick electrode for defibrillation in the right ventricle.
abstract: We hypothesized that a long thin right ventricular (RV) electrode would have equivalent defibrillation threshold (DFT) performance to a short thick electrode with approximately the same surface area. This could lead to thinner transvenous lead systems, which would be easier to implant. A thin (5.1 French) lead was compared to a standard control (10.7 French). The thin lead had an 8-cm RV electrode length with a surface area of 4.26 cm2. The standard lead had a RV electrode length of 3.7 cm and a surface area of 4.12 cm2. A 140-mu French capacitor 65%/65% tilt biphasic defibrillation shock was delivered between the RV electrode and a 14-cm2 subcutaneous patch. DFTs were determined following 10 seconds of fibrillation in 11 dogs by a triple determination averaging technique. The thin lead had a lower resistance (77.1 +/- 27.4 omega vs 88.9 +/- 30.3 omega, P < 0.001) than did the thick lead. There was no significant difference in stored energy DFTs (9.9 +/- 2.5 vs 10.3 +/- 2.7, P = 0.098 2-sided, P = 0.049 1- sided). This was in spite of the fact that the long thin lead had a portion of its RV coil extending above the tricuspid valve and, thus, not contributing efficiently to the ventricular gradients in the small dog heart. We conclude that a long thin right ventricular electrode and a standard short thick electrode had equivalent defibrillation performance. This preliminary result should be confirmed in clinical studies as it could lead to significantly thinner transvenous lead systems.
authors.affiliation: University of Kentucky, Lexington.
authors.forename: F M
authors.initials: FM
authors.lastname: Leonelli
authors.forename: H
authors.initials: H
authors.lastname: Wright
authors.forename: S T
authors.initials: ST
authors.lastname: Latterell
authors.forename: R S
authors.initials: RS
authors.lastname: Nelson
authors.forename: T P
authors.initials: TP
authors.lastname: Adams
authors.forename: M W
authors.initials: MW
authors.lastname: Kroll
mesh_terms: D000818:Animals; D017147:Defibrillators, Implantable; D004285:Dogs; D004554:Electric Countershock / Q000295:instrumentation* / Q000379:methods; D004567:Electrodes, Implanted; D004867:Equipment Design; D006352:Heart Ventricles; D014693:Ventricular Fibrillation / Q000628:therapy