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A Prospective Randomized Comparison in Humans of 90‐μF and 120‐μF Biphasic Pulse Defibrillation Using a Unipolar Defibrillation System
Author(s) -
POOLE JEANNE E.,
KUDENCHUK PETER J.,
DOLACK G.,
JONES GREGORY K.,
DEGROOT PAUL,
JOHNSON GEORGE,
BARDY GUST H.
Publication year - 1995
Publication title -
journal of cardiovascular electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.193
H-Index - 138
eISSN - 1540-8167
pISSN - 1045-3873
DOI - 10.1111/j.1540-8167.1995.tb00387.x
Subject(s) - medicine , defibrillation , cardiology , pulse (music) , defibrillation threshold , voltage , physics , quantum mechanics
90‐μF and 120‐μF Biphasic Pulse Transvenous Defibrillation. Introduction: Capacitance is known to influence defibrillation. Optimal biphasic waveform capacitance for transvenous unipolar defibrillation systems in man is currently being defined. In an effort to improve defibrillation efficacy, we examined the relative defibrillation efficacy of a 65% tilt biphasic pulse from a 90‐μF capacitor compared to a 65% tilt biphasic pulse from a 120‐μF capacitor in a prospective, randomized fashion in 16 consecutive cardiac arrest survivors undergoing defibrillator surgery. Methods and Results: The transvenous unipolar pectoral defibrillation system uses a single endocardial RV anodal defibrillation coil and the shell of an 80‐cc volume (88 cm 2 surface area) pulse generator (Medtronic Model 7219C PCD “active CAN”) as the cathode for the first phase of the biphasic shock: RV + → CAN − . Defibrillation thresholds for each capacitance were determined prospectively in a randomized fashion. The defibrillation threshold results for the 90‐μF capacitance were: leading edge voltage 383 ± 132 V; stored energy 7.4 ± 5.0 J; and resistance 57 ± 10 ω. The results for the 120‐μF capacitance were: leading edge voltage 315 ± 93 V (P = 0.002); stored energy 6.5 ± 3.7 J (P = 0.21); and resistance 57.0 ± 11 ω (P = 0.87). Conclusions: We conclude that 90‐μF, 65% tilt biphasic pulses used with unipolar pectoral defibrillation systems have equivalent stored energy defibrillation efficacy compared to 120‐μF, 65% tilt pulses. Use of lower capacitance is possible in present implantable defibrillators without compromising defibrillation.