13th International Congress
THE "NEW FRONTIERS"
OF ARRHYTHMIAS 1998

January 24-31, 1998
Marilleva, Trento, Italy

RT-56

Repeated IV boluses of class 1C drugs for acute atrial fibrillation termination: a study about 135 patients

Saverio Lavanga, Alessandro Colombo*, Riccardo Bana, Roberto Fornerone, Franco Ferrari, Gianni Rovelli.
*Cardiology Department of Luigi Sacco Hospital, Milan, Cardiology Department of Rho Hospital, Rho, Italy

Background

Class 1C antiarrhythmic agents, intravenously, propafenone and flecainide, have been reported to be effective in converting acute (< 72 hour duration) atrial fibrillation (AF) to sinus rhythm (SR)^1-7. Propafenone has been administered in dosage of 2 mg/kg in 3 minutes¹, in 6 and half minutes², in 10 minutes³ and in 14 minutes⁴. Flecainide has been administered in dosage of 2 mg/kg with a maximum dose of 150 mg in 10 minutes⁵ and in 30 minutes^6,7. AF is the most commonly occurring cardiac arrhythmia, however management strategies for its control are far from satisfactory. Patients with a high ventricular response to AF may develop angina, heart failure, ventricular tachycardia triggered by AF, syncope and occasionally a tachycardia-induced cardiomyopathy. Furthermore, AF has been demonstrated to be associated with a decreased survival regardless of the underlying heart disease⁸. Last, but not least, clinical experience and more recent experimental evidence^9,10 have shown that AF per se may cause electrical changes by changing stretching, refractoriness and many other properties that could favor the progression of acute AF to chronic AF ("atrial fibrillation begets atrial fibrillation"). Therefore we decided to assess the efficacy of repeated IV boluses of either propafenone or flecainide in terminating acute AF in 140 episodes of acute AF among 135 pts, who walked into the cardiology emergency room having an acute AF.