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Biomedical subjects

C A Bonnet

Publications and source records attributed to C A Bonnet.

5 recordsLinked to original sources

Long-term outcome of survivors of cardiac arrest whose therapy is guided by electrophysiologic testing.

The long-term outcome of 217 consecutive survivors of cardiac arrest whose therapy was guided by electrophysiologic testing was analyzed. After electrophysiologic testing, 81 patients (37%) were classified as having no inducible arrhythmia and were treated without antiarrhythmic drugs; 23 received an implantable defibrillator. Of the 136 patients with inducible arrhythmia, the 51 (38%) who responded to serial drug testing were treated with the successful drug and the 85 (62%) with unsuccessful drug testing were treated with an implantable defibrillator (47 patients), amiodarone (36 patients) or drugs that were unsuccessful during testing (2 patients). The mean follow-up interval for all patients was 35 +/- 23 months. The actuarial incidence of sudden death and overall death was similar for patients whose arrhythmias were not inducible, drug responders and nonresponders. The actuarial incidence rate of recurrent arrhythmic events in nonresponders was 35 +/- 5% and 53 +/- 7% at 2 and 5 years, respectively. These values were significantly lower (and statistically similar to each other) in the other two patient groups: patients with noninducible arrhythmia (19 +/- 5% and 31 +/- 7%, respectively, p less than 0.05) and drug responders (13 +/- 5% and 23 +/- 8%, respectively, p less than 0.01). Patients with an implantable defibrillator who had recurrent arrhythmic events were significantly less likely to die suddenly than were patients without a defibrillator who had recurrent events (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Actuarial Analysis

Reproducibility of successful drug trials in patients with inducible sustained ventricular tachycardia.

Patients whose inducible sustained ventricular tachycardia is suppressed during serial electrophysiological testing have a small but gradually increasing actuarial incidence of recurrent arrhythmias despite therapy with the "successful" drug. In an effort to improve the predictive value of a drug response, in 1990 we began to require that our full stimulation protocol be repeated successfully several times before considering a drug to be effective. In 23 consecutive patients who had inducible sustained ventricular tachycardia which was suppressed by at least one drug during invasive serial drug testing using a standard stimulation protocol, the identical stimulation protocol was performed six times during therapy with the initially successful drug (three trials on Day 1 and three trials on Day 2). Repeat trials were completed (i.e., either all six trials were successfully finished or sustained tachycardia was induced) for 29 initially successful drugs in these 23 patients. With 18 of these 29 initially successful drugs (62%), sustained ventricular tachycardia was eventually induced during repeat trials. The eventual drug failures could not be correlated with specific drugs tested, subtherapeutic or falling serum drug levels, marked fluctuations in autonomic tone, or changes in anatomic substrate. The proportion of patients failing each repeat trial was relatively constant: 4/29 (14%) failed Trial 2, 2/25 (8%) failed Trial 3, 7/23 (30%) failed Trial 4, 2/16 (13%) failed Trial 5, and 3/14 (21%) failed Trial 6. The increase in the cumulative incidence of drug failure during repeat trials was nearly linear. Inducibility of ventricular tachycardia appears to be a probability function; a successful drug study should not be regarded as an absolute phenomenon.

Adolescent

Long-term efficacy of an antitachycardia pacemaker and implantable defibrillator combination.

Antitachycardia pacemakers and implantable cardioverter defibrillators (ICD) were implanted in 14 patients to control recurrent hemodynamically stable ventricular tachycardia (VT). All patients underwent extensive preimplant testing in the electrophysiology laboratory documenting that in each patient at least 50 episodes of VT could be reliably terminated by an external model of the antitachycardia pacemaker. The burst scanning mode of antitachycardia pacing was used in all patients. ICDs were implanted solely as a back up should acceleration of VT occur, and all had high nonprogrammable rate cutoffs (mean 191 +/- 12 beats/min). During a mean follow-up of 25 +/- 6 months, 6,029 episodes of VT were treated in the 14 patients. Only 103 ICD discharges were required (approximately one discharge per 60 episodes of VT). Ten of the 14 patients received discharges from their ICDs. No deaths have occurred. All devices remain active and in the automatic mode. Thus, an antitachycardia pacemaker and ICD combination can safely and effectively terminate VT in highly selected patients who are subjected to extensive preimplant testing. In such patients, the vast majority of episodes of VT can be terminated with antitachycardia pacing, and only rarely is a discharge required from the ICD.

Aged