Intravenous amiodarone for the rapid treatment of life-threatening ventricular arrhythmias in critically ill patients with coronary artery disease (original) (raw)

Management of ventricular arrhythmias

Journal of the American College of Cardiology, 1999

Sudden cardiac death accounts for approximately 300,000 deaths annually in the U.S., and most of these are secondary to ventricular tachycardia (VT) and fibrillation in patients with coronary artery disease. Most patients with cardiac death die before reaching the hospital, which brought about a tremendous amount of research focused at identifying patients at high risk. Several trials were initiated to test the effectiveness of various therapeutic measures in these high-risk patients. A history of myocardial infarction, depressed left ventricular function and nonsustained VT have all been identified as independent risk factors for future arrhythmic death. Similarly, patients with a history of sustained VT or a history of sudden cardiac death are a high-risk group and should be aggressively evaluated and treated. The purpose of this article is to discuss risk stratification and primary prevention of sustained ventricular arrhythmias. We also review the recent secondary prevention trials and discuss the options available in the management of patients with sustained ventricular arrhythmias. (J Am Coll Cardiol 1999;34:621-30)

Efficacy and safety of intravenous amiodarone in acute refractory arrhythmias

Clinical Cardiology, 1988

Few data are available on intravenous amiodarone therapy in refractory arrhythmias. This retrospective study in 50 patients (14 with supraventricular and 36 with ventricular tachyarrhythmias) revealed a favorable effect of intravenous amiodarone in the treatment of life-threatening arrhythmias with an overall success rate of 76%. In the subgroup of patients with ventricular fibdlation and concomitant severe congestive heart failure success rate was low (25%, 2/8), whereas effectiveness in patients with ventricular tachycardias was high (> 90%) and proved to be independent of left ventricular function. If patients with recurrent ventricular fibrillation were excluded from the analysis, successful treatment with intravenous amiodarone was achieved in 90%, even in those patients with severely compromised myocardium.

Amiodarone for Resuscitation After Out-ofHospital Cardiac Arrest Due to Ventricular Fibrillation

Annals of Emergency Medicine, 2000

Background Whether antiarrhythmic drugs improve the rate of successful resuscitation after outof-hospital cardiac arrest has not been determined in randomized clinical trials. Methods We conducted a randomized, doubleblind, placebo-controlled study of intravenous amiodarone in patients with out-of-hospital cardiac arrest. Patients who had cardiac arrest with ventricular fibrillation (or pulseless ventricular tachycardia) and who had not been resuscitated after receiving three or more precordial shocks were randomly assigned to receive 300 mg of intravenous amiodarone (246 patients) or placebo (258 patients). Results The treatment groups had similar clinical profiles. There was no significant difference between the amiodarone and placebo groups in the mean (±SD) duration of the resuscitation attempt (42±16 and 43±16 minutes, respectively), the number of shocks delivered (4±3 and 6±5), or the proportion of patients who required additional antiarrhythmic drugs after the administration of the study drug (66 percent and 73 percent). More patients in the amiodarone group than in the placebo group had hypotension (59 percent vs. 48 percent, P=0.04) or bradycardia (41 percent vs. 25 percent, P=0.004) after receiving the study drug. Recipients of amiodarone were more likely to survive to be admitted to the hospital (44 percent, vs. 34 percent of the placebo group; P=0.03). The benefit of amiodarone was consistent among all subgroups and at all times of drug administration. The adjusted odds ratio for survival to admission to the hospital in the amiodarone group as compared with the placebo group was 1.6 (95 percent confidence interval, 1.1 to 2.4; P=0.02). The trial did not have sufficient statistical power to detect differences in survival to hospital discharge, which differed only slightly between the two groups. Conclusions In patients with out-of-hospital cardiac arrest due to refractory ventricular arrhythmias, treatment with amiodarone resulted in a higher rate of survival to hospital admission. Whether this benefit extends to survival to discharge from the hospital merits further investigation.

Control of sudden recurrent arrhythmic deaths: Role of amiodarone

American Heart Journal, 1983

Patients resuscitated after out-of-hospital cardiac arrest have electrical instability of the myocardium, with 30% to 40% propensity for recurrent arrest in the first year. About 85% to 90% of such patients have complex ventricular ectopy and runs of ventricular tachycardia; in 70% to 80%, ventricular tachycardia or fibrillation are inducible by programmed electrical stimulation. The attempt to control recurrent cardiac arrest using these parameters and conventional antiarrhythmic drugs has yielded conflicting or variable results. Amiodarone was therefore studied in 40 consecutive patients (with previous cardiac arrests) in whom conventional antiarrhythmic therapy had proved ineffective or was not tolerated. The mean ejection fraction of the group was 0.29 +/- 0.12. At a mean follow-up of 16 months (range 5 to 40 months) six patients had died, three from heart failure, one from liver failure (not drug induced), and two from sudden (presumably arrhythmic) death. Late occurrences of arrhythmia were found in two patients (complicated by digitalis intoxication in one). Ambulatory ECG recordings showed that amiodarone had a potent suppressant effect on ventricular ectopy and runs of VT, but electrophysiologic studies demonstrated that it did not inhibit inducible VT/VF in greater than 65% despite an excellent clinical outcome. Limiting adverse reaction was seen in only one patient; other relatively minor side effects occurred in 10% to 15% of patients receiving maintenance therapy. Our data provide further evidence for the effectiveness of amiodarone in life-threatening ventricular arrhythmias, with a potential for the prolongation of survival in patients resuscitated after out-of-hospital cardiac arrests.

Ventricular arrhythmias: Use of electrophysiologic studies

American Heart Journal, 1983

The clinical utility of electrophysiologic testing in assessing the long-term efficacy of amiodarone for treatment of life-threatening ventricular arrhythmias is controversial, most investigators reporting little or no correlation between the early effects of the drug on arrhythmia inducibility and subsequent prognosis. We have evaluated 69 consecutive patients given amiodarone for ventricular tachycardia (VT) or fibrillation (VF). All patients underwent provocative electrophysiologic testing with programmed electrical stimulation before and after amiodarone loading. After a standardized amiodarone loading regimen, the patients' arrhythmias were not inducible in 22 patients (group 1) and remained inducible in 47 patients (group 2). No patient in group 1 has had a recurrence of VT/VF, whereas 15 (32%) of 47 patients in group 2 have had recurrences. The characteristics of the arrhythmia induced by programmed stimulation in group 2 accurately predicted the severity of the recurrence. We conclude that electrophysiologic testing may be useful in evaluating the efficacy of amiodarone for the long-term treatment of VT/VF and that its precise role in this context should be further investigated by stringently controlled studies. (AM HEART J 106:881, 1983.