Medication Summary
Drugs with some effect in atrial ectopic tachycardia (AET) include digoxin (used predominantly for rate control), amiodarone, propafenone, flecainide, sotalol, procainamide, and esmolol. [15] Only digoxin and oral amiodarone are devoid of negative inotropic effect. Adequate control may not require the complete abolition of all atrial ectopic beats or runs.
Ivabradine is a novel antiarrhythmic with relatively hemodynamically neutral profile that shows promise as an effective treatment for automatic tachyarrhythmias in pediatric patients. Several case reports describe positive outcomes with no adverse events or side effects. [16, 17, 18]
Antiarrhythmic Agents
Class Summary
These agents alter the electrophysiologic mechanisms responsible for arrhythmia.
Digoxin (Lanoxin, Lanoxicaps)
Digoxin is a cardiac glycoside with direct inotropic effects in addition to indirect effects on the cardiovascular system. This agent acts directly on cardiac muscle, increasing myocardial systolic contractions, and its indirect actions result in increased carotid sinus nerve activity and enhanced sympathetic withdrawal for any given increase in mean arterial pressure. Digoxin is used to control ventricular rate when administering propafenone, flecainide, or procainamide.
Amiodarone (Cordarone)
Amiodarone is a class III antiarrhythmic that may inhibit atrioventricular (AV) conduction and sinus node function. This agent prolongs action potential and refractory period in the myocardium and inhibits adrenergic stimulation. Before administrating amiodarone, control the ventricular rate and congestive heart failure (CHF), if present, with digoxin.
Esmolol (Brevibloc)
Esmolol is a class II antiarrhythmic that is an excellent drug for use in patients at risk of complications from beta blockade, particularly for those with reactive airway disease, mild-to-moderate left ventricular (LV) dysfunction, and/or peripheral vascular disease. This drug has a short half-life of 8 min, which allows for titration to the desired effect and quick discontinuation if needed.
Sotalol (Betapace, Betapace AF, Sorine)
Sotalol is a class III antiarrhythmic agent that blocks potassium channels, prolongs action potential duration, and and lengthens the QT interval. It is a noncardiac selective beta-adrenergic blocker.
Propafenone (Rythmol)
Propafenone is a class IC antiarrhythmic that has local anesthetic properties; it inhibits the fast sodium channels of the myocardial cell membrane and slows the rate of increase of the action potential. This drug treats life-threatening arrhythmias and possibly works by reducing spontaneous automaticity and prolonging the refractory period.
Flecainide (Tambocor)
Flecainide is a class IC antiarrhythmic agent that is used to treat life-threatening ventricular arrhythmias by causing a prolongation of refractory periods and decreasing action potential without affecting duration. This agent blocks sodium channels, producing a dose-related decrease in intracardiac conduction in all parts of the heart, with greatest effect on the His-Purkinje system (H-V conduction). However, its effects on AV nodal conduction time and intra-atrial conduction times, although present, are less pronounced than on ventricular conduction velocity.
Procainamide (Procan, Pronestyl)
Procainamide is a class IA antiarrhythmic used for premature ventricular contractions (PVCs), ventricular tachycardias (VTs), and supraventricular tachycardias (SVTs). This drug increases the refractory period of the atria and ventricles. Myocardiac excitability is reduced by an increase in the threshold for excitation and inhibition of ectopic pacemaker activity.
