Value of holter monitoring in predicting long-term efficacy and inefficacy of amiodarone used alone and in combination with class 1A antiarrhythmic agents in patients with ventricular tachycardia

The value of two reported and two new ambulatory electrocardiographic (Holter) criteria was studied in 80 patients taking amiodarone for refractory recurrent sustained ventricular tachycardia. In the 80 patients, the four Holter criteria were as follows: I—85% or greater reduction of ventricular premature complexes and abolition of couplets and nonsustained ventricular tachycardia in 74 patients who had 10 or more ventricular premature complexes/h, or any couplets or nonsustained ventricular tachycardia/24 hours at baseline; II—abolition of nonsustained ventricular tachycardia in 51 patients who had nonsustained ventricular tachycardia at baseline; III—85% or greater reduction of ventricular premature complexes and abolition of nonsustained ventricular tachycardia in 64 patients who had 30 or more ventricular premature complexes/h at baseline; and IV—85% or greater reduction of ventricular premature complexes and abolition of nonsustained ventricular tachycardia in 73 patients who had 10 or more ventricular premature complexes/h at baseline. Amiodarone was judged effective in, respectively, 51 of 74, 44 of 51, 51 of 64 and 61 of 73 patients by criterion I, II, III or IV. During the follow-up period (19 ± 20 months), there were 19 instances of recurrence of ventricular arrhythmia or sudden death. Actuarial arrhythmia-free survival rate at 24 months was 84, 74, 86 and 85%, respectively, in patients with efficacy by criterion I, II, III or IV and 61, 43, 48 and 39%, respectively, in patients with inef-ficacy (p < 0.015 for all). Many patients with efficacy by Holter criteria, however, had a recurrence of arrhythmia, suggesting insensitivity of these Holter criteria. At 24 months, the respective sensitivity of criteria I, II, III and IV was 53, 29, 50 and 47%, the specificity was 86, 94, 90 and 95% and the predictive accuracy was 73,63, 75 and 76%. Conclusions: 1) Inefficacy of amiodarone therapy by Holter criteria predicts a poor outcome but efficacy does not preclude a poor outcome (insensitivity). 2) Criterion I is the most sensitive but the least specific. 3) Criterion II could be used in only 51 of 80 patients and is the least sensitive. 4) Criterion III (with a stricter entry criterion) could be used in fewer patients than criterion I or IV and accuracy is not better. 5) Criterion IV is the most specific and has the best predictive accuracy. 6) Further studies should be done to identify the predictor of arrhythmia recurrence in patients with Holter criteria of efficacy.