Amiodarone in the treatment of life-threatening ventricular tachycardia: role of Holter monitoring in predicting long-term clinical efficacy.

Forty-two patients with refractory, recurrent life-threatening ventricular tachycardia and spontaneous ventricular tachycardia (greater than or equal to 3 beats, heart rate greater than 100 beats/min) on baseline 24 hour Holter recording were treated with amiodarone. After 1 week of amiodarone therapy and during the follow-up period (22 +/- 11 months, mean +/- SD), patients had serial 24 hour Holter recordings (10.6 +/- 3.8 per patient). Twenty-four hour, 48 hour or 72 hour Holter monitoring was performed during the second week of therapy. Ventricular tachycardia was suppressed on all follow-up serial Holter recordings in 17 patients (40%). Ventricular tachycardia was suppressed in 34 (81%) of 42 patients with 24 hour Holter recordings, 21 (72%) of 29 patients with 48 hour recordings and 20 (69%) of 29 patients with 72 hour recordings during the second week of therapy. At follow-up 24 patients (57%) were free of clinical arrhythmic events (Sustained ventricular tachycardia or sudden death). The sensitivity, specificity, positive and negative predictive values and predictive accuracy of ventricular tachycardia on 24, 48 and 72 hour Holter recordings during the second week of therapy for predicting subsequent events were analyzed. The positive and negative predictive values were 100 and 71% for 24 hour Holter recordings, 88 and 71% for 48 hour recordings and 89 and 75% for 72 hour recordings. Overall predictive accuracy was 76, 76 and 79%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)