The main goal of this study was to assess antiarrhythmic activity of novel aminoalkyl derivatives of imidazo[2,1-f]purine-2,4-dione and imidazolidine-2,4-dione exerting α1 and 5-HT1A receptors affinity. Tested compounds produced prophylactic and therapeutic antiarrhythmic activity in an adrenaline-induced model of arrhythmia. The strongest antiarrhythmic activity as well as the highest α1-adrenoreceptor affinity (Ki = 13.9 nM) was found for 5-methyl-5-phenyl-3-[3-(4-(2-methoxyphenyl)piperazin-1-yl)propyl]-imidazolidine-2,4- dione (12). The results indicated a correlation between α1-adrenoreceptor affinities and antiarrhythmic activity
