title: Optimal electrode configuration for pectoral transvenous implantable defibrillator without an active can.
abstract: A new 83 cm3 implantable cardioverter-defibrillator (ICD) designed for pectoral implantation has been implanted most frequently using right ventricular and superior vena cava (RV-->SVC) electrodes; a patch electrode (RV-->patch + SVC) has been added when necessary to decrease the defibrillation threshold (DFT). The goal of this prospective study was to compare biphasic waveform DFTs for 3 electrode configurations: RV-->patch, RV-->SVC, and RV-->patch + SVC in 25 consecutive patients. The patch was positioned in a left retro-pectoral pocket, and the SVC electrode was positioned with the tip at the junction of the SVC and innominate vein. In the first 15 patients, all 3 electrode configurations were tested in random order; in the last 10 patients, only the RV-->patch and RV-->patch + SVC configurations were tested. In the first 15 patients, the stored-energy DFT for the RV-->SVC configuration (15.2 +/- 7.7 J) was higher (p < 0.001) than the DFT for the RV-->patch configuration (11.3 +/- 6.2 J) and the RV-->patch + SVC configuration (10.0 +/- 5.8 J). For all 25 patients, the DFT was lower for the RV-->patch + SVC configuration (9.7 +/- 5.1 J) than for the RV-->patch configuration (12.4 +/- 6.6 J, p = 0.005). The pathway resistance was highest for the RV-->patch configuration (72 +/- 9 omega), lower for the RV-->SVC configuration (63 +/- 6 omega, p < 0.01), and lowest for the RV-->patch + SVC configuration (46 +/- 3 omega, p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Division of Cardiology, Cedars-Sinai Medical Center, Los Angeles, California, USA.
authors.forename: C D
authors.initials: CD
authors.lastname: Swerdlow
authors.forename: S
authors.initials: S
authors.lastname: Davie
authors.forename: R M
authors.initials: RM
authors.lastname: Kass
authors.forename: P S
authors.initials: PS
authors.lastname: Chen
authors.forename: C
authors.initials: C
authors.lastname: Hwang
authors.forename: W J
authors.initials: WJ
authors.lastname: Mandel
authors.forename: E S
authors.initials: ES
authors.lastname: Gang
authors.forename: S
authors.initials: S
authors.lastname: Raissi
authors.forename: C T
authors.initials: CT
authors.lastname: Peter
mesh_terms: D000368:Aged; D003627:Data Interpretation, Statistical; D017147:Defibrillators, Implantable; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010369:Pectoralis Muscles; D013318:Stroke Volume; D017180:Tachycardia, Ventricular / Q000628:therapy; D014693:Ventricular Fibrillation / Q000628:therapy