title: Efficacy of beta-blocking agents in reducing the number of shocks in patients implanted with first-generation automatic defibrillators.
abstract: The efficacy of beta-blockers was tested in 11 patients who avoided sudden death as a result of ventricular tachycardia or fibrillation due to coronary artery disease or non-ischaemic underlying heart disease, after implantation of an automatic defibrillator. Ten patients initially tolerated acebutolol despite prior class III or IV heart failure in six cases; nadolol replaced acebutolol in nine cases for long-term therapy. In these 10 patients, periods of treatment with and without beta-blocking agent were available, making possible a crossover comparison, during a follow-up lasting 31.6 +/- 17.8 months. One hundred and ten shocks were delivered: 14 were considered as probably inappropriate and ruled out, leaving the remaining 96 shocks to be analysed. The monthly rate of shocks was lower during beta-blocking treatment: 0.12 +/- 0.24 vs. 1.09 +/- 1.41 (P = 0.03). While taking beta-blockers, only four patients received shocks, compared to 10 (i.e. all cases) not administered beta-blockers (P less than 0.01). Despite the technical limitations of the study, since only a few spontaneous shocks could be documented on ECG recordings, the efficacy of beta-blockers in preventing occurrence of severe ventricular tachyarrhythmias seems likely, and deserves further investigations using new implanted devices with improved memory functions.
authors.affiliation: Department of Cardiology, University Lariboisière Hospital, Paris, France.
authors.forename: J F
authors.initials: JF
authors.lastname: Leclercq
authors.forename: A
authors.initials: A
authors.lastname: Leenhardt
authors.forename: P
authors.initials: P
authors.lastname: Coumel
authors.forename: R
authors.initials: R
authors.lastname: Slama
mesh_terms: D000070:Acebutolol / Q000008:administration & dosage*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000638:Amiodarone / Q000008:administration & dosage; D003131:Combined Modality Therapy; D004305:Dose-Response Relationship, Drug; D004359:Drug Therapy, Combination; D004554:Electric Countershock / Q000295:instrumentation*; D015716:Electrocardiography, Ambulatory / Q000187:drug effects; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019736:Prostheses and Implants; D017180:Tachycardia, Ventricular / Q000503:physiopathology / Q000628:therapy*; D014693:Ventricular Fibrillation / Q000503:physiopathology / Q000628:therapy*
chemical_list: D000070:Acebutolol; D000638:Amiodarone