Initial and long-term outpatient experience with lorcainide for suppression of malignant and potentially malignant ventricular arrhythmias

Antiarrhythmic drug therapy for suppression of ventricular arrhythmia: experience with 122 patients treated for two years

Although there are many reports of the short-term effectiveness of antiarrhythmic drugs for suppression of ventricular ectopic depolarizations, there are less data available on the long-term use of these drugs. We treated 122 patients for up to 2 years with antiarrhythmic drugs for suppression of frequent ventricular ectopic depolarizations. The percent suppression of ventricular ectopic depolarizations and nonsustained ventricular tachycardia for each drug was determined at 1, 3, 6, 12, 18, and 24 months of therapy. Among 33 patients treated with flecainide, the mean suppression of ventricular ectopic depolarizations (average of all data during 24 months) was 93 +/- 17% and of nonsustained ventricular tachycardia was 97 +/- 7%. In 27 patients treated with encainide, the mean suppression of ventricular ectopic depolarizations was 88 +/- 18% and of ventricular tachycardia was 95 +/- 16%. Among 26 patients treated with propafenone, the mean suppression of ventricular ectopic depolarizations was 77 +/- 32% and of ventricular tachycardia was 93 +/- 15%. For the 20 patients treated with moricizine, the mean suppression of ventricular ectopic depolarizations was 62 +/- 35% and of ventricular tachycardia was 90 +/- 14%. Among 16 patients treated with amiodarone, the mean suppression of ventricular ectopic depolarizations was 92 +/- 14% and of nonsustained ventricular tachycardia was 99 +/- 3%. In 54 of the 122 patients (44%), the study drug was stopped during 2 years of therapy because of death (2 sudden, 2 unwitnessed and 6 noncardiac), side effects (21 patients), lack or of loss of efficacy (13 patients), and noncompliance (10 patients).(ABSTRACT TRUNCATED AT 250 WORDS)

Newer antiarrhythmic drugs

The effective management of cardiac arrhythmias remains a major challenge in cardiovascular therapeutics. The management of arrhythmias encompasses a wide spectrum of supraventricular and ventricular tachyarrhythmias occurring in patients with various cardiac diagnoses and different degrees of myocardial dysfunction. A number of the newer antiarrhythmic drugs that have either recently been released or appear promising are reviewed in this article. Drugs are described with respect to their basic pharmacology, electrophysiologic actions, pharmacokinetics and metabolism, hemodynamics, antiarrhythmic effects, side effects, interactions, indications, and dosage.

Long-term experience with sotalol in the treatment of complex ventricular arrhythmias

Sotalol was given for extended therapy to 22 of 29 patients with frequent (greater than or equal to 30/hour) complex premature ventricular complexes (PVCs) who had participated in a short-term study of sotalol vs placebo. Open-label sotalol was given in individually titrated divided doses of 160 to 800 mg/day (median 323, mean 386 mg/day). Response was assessed at approximately 1, 6, and 12 months or until patient discontinuation. The period of sotalol therapy averaged 9 months (range, 0.2 to 22.7). At about 1 month, 13 (59%) of 22 patients showed effective control of arrhythmia. The median percentage change in total PVCs for individual patients at 1 month was -70% and for repetitive PVCs it was -95%. At about 6 months, 10 (45%) of the 22 patients continued to be successfully treated; at about 12 months, seven patients continued on sotalol, six (27%) successfully treated according to Holter criteria. Reasons for discontinuation included lack of efficacy in nine, adverse effects in four (fatigue in three, bradycardia with sinus pauses in one), and miscellaneous reasons in two. ECG PR and especially QTc intervals increased significantly during therapy (p less than 0.02, p less than 0.01, respectively). In summary, sotalol is a moderately effective antiarrhythmic agent in patients with complex PVCs, but during long-term therapy a rather high dropout rate was observed because of arrhythmia recurrence or adverse effects.

Occurrence of exercise-induced and spontaneous wide complex tachycardia during therapy with flecainide for complex ventricular arrhythmias: a probable proarrhythmic effect

Flecainide acetate, a new antiarrhythmic agent, possesses favorable pharmacokinetic and hemodynamic properties and demonstrates highly favorable antiarrhythmic activity in patients with ventricular arrhythmias. However, the proarrhythmic potential of flecainide deserves further evaluation. In 7 (13%) of 55 consecutive patients treated with oral flecainide, 200 to 600 mg/day, for complex ventricular arrhythmias (including sustained ventricular tachycardia in 14), we observed the appearance of new or more sustained exercise-induced (five patients) or spontaneous (two patients) wide complex tachycardia. The mechanism of wide complex tachycardia appeared to be ventricular tachycardia in all seven. In our series, episodes were self-remitting or successfully treated. In four patients, wide complex tachycardia did not recur during exercise testing during alternative antiarrhythmic therapy (three patients) or no antiarrhythmic therapy (one patient). These observations raise the possibility of flecainide-related proarrhythmia, manifested as an increased propensity to exercise (activity)-induced wide complex tachycardia, which was not reliably predicted by results of Holter recordings or programmed electrical stimulation. Patients with complex ventricular arrhythmias beginning long-term treatment with oral flecainide should be considered for treadmill exercise testing together with ambulatory monitoring as part of the initial assessment of drug efficacy.

Recainam, a potent new antiarrhythmic agent: effects on complex ventricular arrhythmias

The antiarrhythmic efficacy and safety of intravenous recainam, a newly synthesized compound displaying potent class I antiarrhythmic activity, were tested in 10 hospitalized patients with frequent (greater than 30/h) complex ventricular ectopic beats. There were seven men and three women of average age 57 years (range 21 to 74); five had ischemic heart disease, three had cardiomyopathy and two had valvular heart disease. Recainam was given as a 3.0 mg/kg per 40 min loading infusion followed by a 0.9 mg/kg per h maintenance infusion over a 24 hour observation period. Arrhythmia response was assessed both in the short term (comparing 2 hours before and 1 hour after drug loading) and in the long term (comparing 48 hours before drug loading and 23 hours of maintenance infusion). The median frequency of total premature ventricular complexes decreased in the short term by 99.6% (from 392.5 to 1.5/h, p less than 0.005) and in the long term by 99.7% (from 435 to 1.3/h, p less than 0.01). Repetitive beats were suppressed by a median of 100% both in the short term (p less than 0.006) and during 24 hour infusion (from 80.9 to 0/h, p less than 0.003). More than 90% suppression of repetitive beats occurred in all 10 patients (100%) and more than 90% suppression of total arrhythmias occurred in 9 patients (90%) during the maintenance period. Electrocardiographic PR and QRS intervals increased by 19% (p less than 0.001) and 24% (p less than 0.003), respectively, during therapy, but the JTc interval decreased (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)