ORAL AMIODARONE LOADING FOR THE RAPID TREATMENT OF FREQUENT, REFRACTORY, SUSTAINED VENTRICULAR ARRHYTHMIAS ASSOCIATED WITH CORONARY-ARTERY DISEASE

To evaluate the efficacy and safety of oral amiodarone in the treatmen t of recurrent, sustained, refractory ventricular arrhythmias, rapid h igh-dose oral loading was used to treat 12 critically ill patients wit h frequent, sometimes incessant, sustained ventricular arrhythmias ref ractory to 2 to 6 antiarrhythmic agents. Presenting arrhythmias includ ed sustained monomorphic ventricular tachycardia and ventricular fibri llation associated with cardiac arrests in 6 patients. Patients experi enced 2 to 10 episodes (mean 5 +/- 2) of sustained ventricular arrhyth mias over a mean period of 6.2 +/- 5.0 days (range 1 to 14) before ora l amiodarone was initiated at 1,200 to 1,400 mg/day. This included at least 1 to 4 episodes (mean 2.2 +/- 1.1) within 24 hours before amioda rone. One to 4 antiarrhythmic drugs were administered concurrently dur ing amiodarone loading. Sustained ventricular arrhythmias no longer oc curred after a mean of 5.2 days (range 1 to 22) with amiodarone. Arrhy thmias were controlled in 4 patients within 24 hours, 5 patients withi n 48 hours, 7 patients within 4 days and 10 patients within 6 days. Pa tients experienced a mean of 0.6 +/- 0.8 episodes within 24 hours afte r amiodarone. Nine patients survived to hospital discharge. No patient had significant adverse effects during high-dose loading. In conclusi on, high-dose oral amiodarone loading, when added to previously unsucc essful conventional antiarrhythmic therapy, is safe and often rapidly effective for at least short-term control of frequent, refractory, sus tained ventricular arrhythmias.