title: Effects of long-term amiodarone therapy on the defibrillation threshold and the rate of shocks of the implantable cardioverter-defibrillator.
abstract: The effects of long-term amiodarone therapy on the defibrillation thresholds and the rate of shocks were evaluated in 62 patients who had implantation of an automatic cardioverter-defibrillator (n = 53) or prophylactic implantation of patch electrodes (n = 9) who were survivors of sudden cardiac death (n = 34) or had refractory rapid ventricular tachycardia (n = 28). There were 53 men and 9 women, with ages ranging from 18 to 76 years (mean +/- SD, 60 +/- 12). Coronary artery disease occurred in 50 patients (80.6%), cardiomyopathy occurred in six (9.7%), valvular heart disease developed in two (3.2%), primary electrical disease developed in two (3.2%), hypertensive heart disease materialized in one (1.6%), and Ebstein's anomaly occurred in one (1.6%). The left ventricular ejection fraction varied from 10% to 75% (mean, 37 +/- 17%). All patients had failed a mean of 3.9 +/- 1.6 antiarrhythmic drugs prior to implantation of the device. Twenty-eight patients (45%) were taking amiodarone up to the time of surgery, with a mean daily dose of 406 +/- 147 mg (range 200 to 800) and for a mean duration of 6.0 +/- 6.7 months (range 1 to 36 months). The mean defibrillation threshold (DFT) was 12.0 +/- 4.4 joules (range 5 to 20) in the group taking amiodarone and was not significantly different from that of the group not taking amiodarone (n = 32) (mean DFT 12.3 +/- 5.5 joules, range 5 to 30; p = 0.77).(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Medicine, University of Massachusetts Medical Center, Worcester 01655.
authors.forename: S K
authors.initials: SK
authors.lastname: Huang
authors.forename: W L
authors.initials: WL
authors.lastname: Tan de Guzman
authors.forename: J G
authors.initials: JG
authors.lastname: Chenarides
authors.forename: N O
authors.initials: NO
authors.lastname: Okike
authors.forename: T J
authors.initials: TJ
authors.lastname: Vander Salm
mesh_terms: D000638:Amiodarone / Q000627:therapeutic use*; D003645:Death, Sudden / Q000453:epidemiology; D004554:Electric Countershock / Q000295:instrumentation*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D019736:Prostheses and Implants; D013610:Tachycardia / Q000453:epidemiology / Q000628:therapy*; D013997:Time Factors; D014693:Ventricular Fibrillation / Q000453:epidemiology / Q000628:therapy*
chemical_list: D000638:Amiodarone