Objective: To review the experience of the Arrhythmology Department in evaluating antiarrhythmic therapy for ventricular arrhythmias with serial Holter electrocardiographic recordings (ECG-H). To compare the results obtained with the most used drugs in this Department: amiodarone and propafenone (groups AMIO and PROP).
Design: Retrospective study. No statistically significant differences between the two groups were found in respect to age, sex, underlying disease, functional class, left ventricular function and associated therapy.
Setting: Arrythmology Department at a Cardiology Service.
Patients: 105 sequential patients with ventricular arrhythmias in a basal ECG-H recording, that were evaluated within 1 year with a new recording on amiodarone or propafenone, without major clinical events or therapeutic changes between the two recordings. INTERVENTIONS (daily oral doses): Amiodarone 200-600 (mean 270) mg or propafenone 300-900 (mean 602) mg.
Results: No statistically significant differences were found between the two groups, in either the basal ECG-H or that recorded on therapy. The two drugs were similar in the degree of suppression of ventricular premature complexes per hour (VPCH): equal or superior to 75% in 64.3% of the patients on amiodarone and in 63.9% of those on propafenone. The following reductions on therapy were statistically significant (p less than 0.001 if not specified): VPCH, from 346 +/- 480 to 86 +/- 158 on amiodarone and from 418 +/- 524 to 110 +/- 215 on propafenone; most complex arrhythmia recorded, on both drugs; number of patients with pairs, from 72.1 to 34.9% on amiodarone and from 69.4 to 33.9% on propafenone; number of patients with runs of nonsustained ventricular tachycardia (VT), from 27.9 to 2.3% on amiodarone (p less than 0.01); number of runs of VT per recording, from 3 +/- 5 to 1 on amiodarone (p less than 0.06); and maximum number of complexes per run of VT, from 8 +/- 8 to 4 on amiodarone and from 7 +/- 4 to 5 +/- 1 on propafenone (both with p less than 0.06).
Conclusions: Holter recordings were useful in evaluating antiarrhythmic therapy. The effectiveness of amiodarone and propafenone in treating ventricular arrhythmias was not significantly different. The choice between one of these drugs must rely on their collateral effects profile.