Treatment of recent onset atrial fibrillation with intravenous sotalol and/or flecainide

The Use of Intravenous Sotalol in Cardiac Arrhythmias

Sotalol is a non-selective beta-adrenergic blocking agent without intrinsic sympathomimetic activity. It has the additional unique property of producing pronounced prolongation of the cardiac action potential duration. Sotalol therapy has been indicated for the management of supraventricular arrhythmias, refractory life threatening ventricular arrhythmias and atrial fibrillation/flutter. Until recently, sotalol was only available in the oral form, however, it was approved for intravenous administration by the US Food & Drug Administration (FDA). The current recommendations are for sotalol 75-150mg to be administered intravenously over 5hours. This rate of administration does not reflect the majority of the research that has been performed with regards to intravenous sotalol. Also, the safety of intravenous bolus dosing of 100mg over 1 and 5minutes has previously been demonstrated. The antiarrhythmic action of sotalol depends on its ability to prolong refractoriness in the nodal and extra nodal tissue. Hence, by giving a lower dose over a long duration, patients may not necessarily benefit from its anti-arrhythmic potential. The purpose of this article is to review the research that has been conducted with regards to dosage and safety of intravenous sotalol, its electrophysiological effects and finally the spectrum of arrhythmias in which it has been used to date.

Efficacy of Intravenous Sotalol for Treatment of Incessant Tachyarrhythmias in Children

Our objective was to evaluate the efficacy and safety of intravenous (IV) sotalol in the treatment of incessant tachyarrhythmias in children with normal cardiac function. Eighty-three children admitted to hospital from October 2011 to December 2014 were treated with IV sotalol or IV sotalol plus IV propafenone. The time to conversion to sinus rhythm and maintaining sinus rhythm were evaluated. Blood pressure, heart rate, QTc, PR intervals, and rhythm were monitored; 50 patients (60%) were converted to sinus rhythm with IV sotalol; time to conversion was 12.0 ± 18.0 hours; 12 additional patients (15%) were converted with IV sotalol combined with IV propafenone; time to conversion was 13.1 ± 17.6 hours. A total of 62 patients (75%) were converted. Success rates of IV sotalol for different tachycardias were similar, whereas the time to conversion differed. The time to conversion for atrioventricular reentrant tachycardia was shorter than atrial tachycardia or atrial flutter (p <0.05). QTc prolongation (from 253 to 486 ms and from 398 ms to 500 ms) was seen in 2 patients (2%) within 48 hours after conversion. The QTc reverted to normal range at 48 and 144 hours, respectively, after withdrawal of IV sotalol. A 1 month old with atrial flutter developed bradycardia (7:1 atrioventricular conduction) 5 minutes after IV sotalol, and heart rate increased gradually after drug withdrawal. No other adverse effects were observed. In conclusion, IV sotalol can be safely and effectively used to terminate pediatric tachycardias in patients with normal cardiac function. No proarrhythmic or significant toxicities were detected. Close monitoring of QTc and heart rate is required after IV sotalol. Adding IV propafenone to IV sotalol in resistant cases enhance conversion.

Oral loading single dose flecainide for pharmacological cardioversion of recent-onset atrial fibrillation

The efficacy and safety of the single oral loading dose of flecainide for cardioversion of recent-onset atrial fibrillation was examined by reviewing the trials on the subject identified through a comprehensive literature search. Most of the trials used a single dose of 300 mg for oral loading. The success rate ranged from 57 to 68% at 2-4 h and 75 to 91% at 8 h after drug administration. The conversion time ranged from 110+/-82 to 190+/-147 min, depending on the duration of observation after drug administration, which in most trials was of 8 h. Single oral loading regimen of flecainide was significantly more efficacious than placebo, and was as efficacious as the single oral loading regimen of propafenone. Both the single oral loading and the intravenous loading regimens of flecainide were equally efficacious but the intravenous regimen resulted in an earlier conversion. Adverse effects reported were mild non-cardiac side effects, reversible QRS complex widening, transient arrhythmias and left ventricular decompensation. The transient arrhythmias were chiefly at the time of conversion and included appearance of atrial flutter and sinus pauses. No life-threatening ventricular arrhythmia or death was reported. The single dose oral loading regimen of flecainide appears to be effective for cardioversion of recent-onset atrial fibrillation with a relatively rapid effect within 2-4 h, and is free of serious complications in patients without structural heart disease. Patients with substantial structural heart disease were excluded from most of the trials.