to study the effects of an atrial premature beat on atrial refractory periods , we investigated 11 patients ( group a ) who were the control group , 12 patients suffering from paroxysmal atrial fibrillation ( group b ) , and 10 patients ( group c ) without arrhythmias but with cardiopathy or cardiomyopathy .
C0018799
cardiopathy
C0878544
cardiomyopathy