[Effect of etmozin and ethacizin (diethylamino analog of etmozin) on local microcardiac blood flow and the fibrillation threshold of the heart].

Using the thermoclearance method, the antiarrhythmic drugs ethmozine and ethacizine (a diethylamine analogue of ethmozine) were shown to improve the blood supply of the ischemic zone which developed acute occlusion of the canine coronary following artery. The effects of the drugs were most prominent in the subepicardial area. The occlusion of the coronary artery resulted in a reduction of the local blood flow in the subepicardial are by 75.6 +/- 4.6% in the control group, by 54.2 +/- 9.7% (p less than 0.05) in the ethmozine group (3 mg/kg) and by 34.2 +/- 8.2% (p less than 0.05) in the group receiving ethacizine (1 mg/kg). In acute experiments on cats both drugs increased the threshold of cardiac fibrillation induced by high frequency electric stimulation. Following the administration of ethmozine (3 mg/kg), the threshold of right atrial fibrillation enhanced by 187 +/- 70% (p less than 0.05) while with ethacizine (1 mg/kg) it rose by 181 +/- 66% (p less than 0.05). The increase in the threshold of right ventricle fibrillation for ethmozine constituted 82 +/- 41% (p less than 0.05) and for ethacizine 77 +/- 38% (p less than 0.05).