Ninety-six patients with recurrent, drug-refractory tachyarrhythmias were treated with amiodarone for 8.0 + 7.5 months (range 1 day to 27 months): 77 for recurrent ventricular tachycardia or ventricular fibrillation (VT/VF), two for complex ventricular ectopy, and 17 for supraventricular tachyarrhythmias. The actuarial incidence of successful amiodarone therapy was 52 + 7% at 12 months and 28 + 9% at 24 months for patients with VT/VF. Neither patient with complex ventricular ectopy was successfully treated. Among the patients with supraventricular tachyarrhythmias, 64.7% were successfully treated for 7.7 + 7.6 months (range 1 to 22 months). Amiodarone toxicity occurred in 66 of 91 patients (72.5%) treated for more than 1 week. Fourteen patients had therapy-limiting toxicity. Of these 14, six had pulmonary toxicity, four had arrhythmia exacerbation, one had hepatitis, one had renal toxicity, one had rash, and one had erythema nodosum. The actuarial incidence of therapy-limiting side effects was 27 + 7% at 15 months. We conclude that amiodarone is useful in the treatment of refractory tachyarrhythmias but that the rate of efficacy in VT/VF is lower and the incidence of significant toxicity is higher than has Circulation 68, No. 1, 88-94, 1983.

We propose a descriptive classification scheme that 1) fully describes and tabulates all significant aspects of terminal events; 2) incorporates previously used categorizations of death and new categorizations that address unique aspects of arrhythmia investigations; and 3) tabulates sufficient data to allow comparison with other studies. Events in a clinical trial of implantable defibrillator therapy were classified using the new classification scheme.

The actuarial incidence and pattern of occurrence of shocks were analyzed in 65 patients after implantation of the automatic implantable cardioverter defibrillator. During a mean follow-up of 25 +/- 21 months only one patient died suddenly, and this patient had a nonfunctioning device at the time of death. The long-term actuarial risk of death from any cause in the patients who received appropriate shocks was not significantly different than for the entire group. The 1- and 4-year cumulative risk of receiving any shock was 51 +/- 7% and 81 +/- 11%; of receiving an appropriate shock was 33 +/- 7% and 64 +/- 10%; of receiving a spurious shock was 17 +/- 5% and 21 +/- 6%; and of receiving an "indeterminate" shock was 19 +/- 6% and 52 +/- 10%. In 14 patients who were followed for 24 months without receiving an appropriate shock, the actuarial risk of receiving an appropriate shock was 29 +/- 14% during the next 24 months. The mean number of shocks delivered during appropriate episodes was 1.6 +/- 0.9, which was significantly lower than the mean of 4.0 +/- 2.0 shocks during spurious episodes (P less than 0.02). The mean number of shocks during indeterminate episodes was 1.7 +/- 1.5. Our data confirms the efficacy of the implantable defibrillator in preventing sudden death. The majority of patients with this device receive appropriate shocks during long-term follow-up, and the cumulative incidence of appropriate shocks increases steadily for at least 4 years. In contrast, the cumulative incidence of spurious shocks plateaus at about 12 months. Our data suggests that many "indeterminate" shocks actually appear to be appropriate.

The Corventis NUVANT™ Mobile Cardiac Telemetry system is an innovative solution in the field of continuous monitoring of symptomatic and asymptomatic cardiac abnormalities to help physicians diagnose and treat non-lethal cardiac arrhythmias. As an FDA cleared product on the market for more than 2 years, the collected body of patient data represents a unique and powerful source of clinical information. Analysis of a sample of 951 NUVANT patients has revealed interesting statistics on the prevalence of various cardiac arrhythmias in the patient population. The population is non-randomized and largely consists of US patients where a traditional Holter Monitor study was negative. The analysis here is focused on classifying the detected arrhythmias using potential therapy solutions as a classifier. Across the total population, 2.2% of patients presented arrhythmias indicating assessment for clinically significant tachycardia, 19% indications of potential bradycardia, 20% had indications of atrial fibrillation, 1% indicating arrhythmias requiring other conditional treatment, and 58% presenting arrhythmias likely not requiring treatment.

No abstract