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The results of surgical therapy performed in 51 consecutive patients with ventricular tachycardia were reviewed to determine short- and long-term predictors of success of such therapy in preventing recurrences of life-threatening ventricular arrhythmias. Of 41 patients (80%) who survived surgery, 40 had postoperative programmed stimulation and, of these patients, 78% ( n = 31) had no inducible ventricular tachycardia on no antiarrhythmic therapy. This group had a very low incidence of arrhythmia recurrence, with only one nonfatal episode of ventricular tachycardia after a mean follow-up of 41 ± 30 months. In contrast, two of the nine patients (22%) who had inducible arrhythmias postoperatively had cardiac arrest ( p = 0.12). Multivariate analysis identified two significant predictors of perioperative mortality in our patients: increased duration of cardiopulmonary bypass time and increased baseline pulmonary capillary wedge pressure. It is concluded that (1) patients who do not have inducible ventricular tachycardia after arrhythmia surgery have a very low incidence of recurrent arrhythmia and (2) prolonged time of cardiopulmonary bypass and increased pulmonary capillary wedge pressure are predictive of perioperative mortality.

The effects of long-term amiodarone therapy on the defibrillation thresholds and the rate of shocks were evaluated in 62 patients who had implantation of an automatic cardioverter-defibrillator ( n = 53) or prophylactic implantation of patch electrodes ( n = 9) who were survivors of sudden cardiac death ( n = 34) or had refractory rapid ventricular tachycardia ( n = 28). There were 53 men and 9 women, with ages ranging from 18 to 76 years (mean ± SD, 60 ± 12). Coronary artery disease occurred in 50 patients (80.6%), cardiomyopathy occurred in six (9.7%), valvular heart disease developed in two (3.2%), primary electrical disease developed in two (3.2%), hypertensive heart disease materialized in one (1.6%), and Ebstein's anomaly occurred in one (1.6%). The left ventricular ejection fraction varied from 10% to 75% (mean, 37 ± 17%). All patients had falled a mean of 3.9 ± 1.6 antiarrhythmic drugs prior to implantation of the device. Twenty-eight patients (45%) were taking amiodarone up to the time of surgery, with a mean daily dose of 406 ± 147 mg (range 200 to 800) and for a mean duration of 6.0 ± 6.7 months (range 1 to 36 months). The mean defibrillation threshold (DFT) was 12.0 ± 4.4 joules (range 5 to 20) in the group taking amiodarone and was not significantly different from that of the group not taking amiodarone ( n = 32) (mean DFT 12.3 ± 5.5 joules, range 5 to 30; p = 0.77). After discharge from the hospital, 53 patients were followed for a mean of 17.8 ± 14.4 months (range 1 to 63), and 25 (47%) of them were continued on a regimen of amiodrone with a mean daily dose of 344 ± 122 mg (range 100 to 600). A total of 179 presumably appropriate shocks were registered in 8 of 25 patients (32%) taking amiodarone and 126 appropriate shocks were given in 8 of 28 patients (29%) who were not taking amiodarone. This study suggests that (1) long-term amiodarone therapy does not increase the defibrillation thresholds in patients undergoing implantation of an automatic cardioverter-defibrillator and (2) a significant number of patients receiving long-term amiodarone therapy continue to suffer from ventricular tachyarrhythmias and require repeated shocks from the device.