title: Clinical predictors of defibrillation energy requirements in patients treated with a nonthoracotomy defibrillator system. The ResQ Investigators.
abstract: Many factors can influence defibrillation energy requirements (DER) in patients with a nonthoracotomy defibrillator. No large studies, however, have correlated clinical characteristics with the DER. In this study, 124 patients underwent the same DER protocol with the identical biphasic waveform, nonthoracotomy lead system, and lead configuration. These patients were 63 +/- 12 years old (mean +/- SD); 99 were men; the ejection fraction was 0.32 +/- 0.13, and 36 were taking an antiarrhythmic medication. New York Heart Association congestive heart failure class I was present in 28, class II in 70, and class III in 26 patients. Male sex (454 +/- 94 V vs 406 +/- 91 V for female sex) was associated with a significantly higher DER (p = 0.02) and an increased risk of a DER > 550 V (p = 0.047). No other clinical variable was associated with the DER or a DER > 550 V. In conclusion, women tend to have lower DERs than men.
authors.affiliation: Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor 48109-0022, USA.
authors.forename: S A
authors.initials: SA
authors.lastname: Strickberger
authors.forename: S L
authors.initials: SL
authors.lastname: Brownstein
authors.forename: B L
authors.initials: BL
authors.lastname: Wilkoff
authors.forename: A J
authors.initials: AJ
authors.lastname: Zinner
mesh_terms: D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use; D017147:Defibrillators, Implantable; D004554:Electric Countershock / Q000379:methods; D004567:Electrodes, Implanted; D004867:Equipment Design; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D012737:Sex Factors; D013318:Stroke Volume; D017180:Tachycardia, Ventricular / Q000453:epidemiology / Q000628:therapy*; D013908:Thoracotomy; D014693:Ventricular Fibrillation / Q000453:epidemiology / Q000628:therapy*
chemical_list: D000889:Anti-Arrhythmia Agents