The effects of the new antiarrhythmic E 047/1 on postoperative ischemia-induced arrhythmias in dogs

Perioperative malignant ventricular tachyarrhythmias pose an imminent clini cal danger by potentially precipitating myocardial ischemia and severely co mpromising hemodynamics. Thus, immediate and effective therapy is required, which is not always provided by currently recommended IV drug regimens, in dicating a need for more effective drugs. We examined antiar-rhythmic effec ts of the new benzofurane compound E 047/1 on spontaneous ventricular tachy arrhythmia in a conscious dog model. One day after experimental myocardial infarction, 40 dogs exhibiting tachyarrhythmia randomly received (bolus plu s l-h infusion) E 047/1 6 mg/kg plus 6 mg.kg(-1).h(-1), lidocaine 1 mg/kg p lus 4.8 mg.kg(-1).h(-1), flecainide 1 mg/kg plus 0.05 mg kg amiodarone 10 m g/kg plus 1.8 mg.kg(-1).h(-1), or bretylium 10 mg/kg plus 20 mg.kg(-1).h(-1 ). Electrocardiogram was evaluated for number of premature ventricular cont ractions (PVC), normally conducted beats originating from the sinoatrial no de, and episodes of ventricular tachycardia. Immediately after the bolus, E 047/1 reduced PVCs by 46% and increased sinoatrial beats from 4 to 61 bpm. The ratio of PVCs to total beats decreased from 98% to 58%. Amiodarone and flecainide exhibited antiarrhythmic effects with delayed onset. Lidocaine did not suppress PVCs significantly, and bretylium was proarrhythmic. The a ntiarrhythmic E 047/1 has desirable features, suppressing ischemia-induced ventricular tachyarrhythmia quickly and efficiently, and may be a useful ad dition to current therapeutic regimens. Implications: Life-threatening arrh ythmias of the heart after myocardial infarction or ischemia may be treated quickly and efficiently by the new drug E 047/1.