Utilizing standard microelectrode stimulation and recording techniques, the electrophysiologic effects of the new antiarrhythmic agent sotalol were studied in Purkinje′s fibers obtained from six nascent mongrel canin...Utilizing standard microelectrode stimulation and recording techniques, the electrophysiologic effects of the new antiarrhythmic agent sotalol were studied in Purkinje′s fibers obtained from six nascent mongrel canines (ages 5～15 days) and were compared to changes observed in the adult canine Purkinje′s fibers (n=6). A dose dependent lengthening of the faction potential duration (APD) was observed in the nascent group and the overall increase in APD was significantly greater than that observed in the adult group. Sotalol also produced dose dependent changes in the effective refractory. period (ERP) in both groups though the overall increase in ERP in the nascent group was again greater. We conclude that the immature canine heart appears to be quite sensitive to the class Ⅲactions of sotalol, with changes in APD and ERP being comparable if not greater in magnitude than that observed in the adult.展开更多
The electrophysiological effects of 5.8×10<sup>-6</sup> mol/L propafenonewere studied in neonatal canine Purkinje fiber compared with changes in theadult canine. The method used was microelectrode tec...The electrophysiological effects of 5.8×10<sup>-6</sup> mol/L propafenonewere studied in neonatal canine Purkinje fiber compared with changes in theadult canine. The method used was microelectrode technique. This study sug-gests that Purkinje fibers are less sensitive to propafenone in the neonate than inthe adult, but at shorter ample lengths, the difference between them is not sig-nificant.展开更多
文摘Utilizing standard microelectrode stimulation and recording techniques, the electrophysiologic effects of the new antiarrhythmic agent sotalol were studied in Purkinje′s fibers obtained from six nascent mongrel canines (ages 5～15 days) and were compared to changes observed in the adult canine Purkinje′s fibers (n=6). A dose dependent lengthening of the faction potential duration (APD) was observed in the nascent group and the overall increase in APD was significantly greater than that observed in the adult group. Sotalol also produced dose dependent changes in the effective refractory. period (ERP) in both groups though the overall increase in ERP in the nascent group was again greater. We conclude that the immature canine heart appears to be quite sensitive to the class Ⅲactions of sotalol, with changes in APD and ERP being comparable if not greater in magnitude than that observed in the adult.
文摘The electrophysiological effects of 5.8×10<sup>-6</sup> mol/L propafenonewere studied in neonatal canine Purkinje fiber compared with changes in theadult canine. The method used was microelectrode technique. This study sug-gests that Purkinje fibers are less sensitive to propafenone in the neonate than inthe adult, but at shorter ample lengths, the difference between them is not sig-nificant.
