Toda H, Watanabe Y
J Electrocardiol. 1979 Jul;12(3):283-93. doi: 10.1016/s0022-0736(79)80062-x.
The electrophysiologic effects of etafenone hydrochloride (Dialicor) were studied in isolated rabbit hearts and canine or rabbit cardiac tissues with intracellular microelectrode techniques. The concentration range used was 0.25-10 mg/L, except in experiments with direct addition of etafenone into the tissue bath. Etafenone depressed automaticity in the sinus node, atrioventricular junction and Purkinje fibers at concentrations not affecting the action potential contour. In both atrial and ventricular fibers, etafenone prolonged the action potential duration and total refractory period. The action potential upstroke was slowed and conduction time increased. Higher concentrations reduced the resting potential, causing incomplete depolarization. Atrial action potentials were affected at lower concentrations than ventricular and Purkinje action potentials. Occasi-nally, etafenone produced localized conduction block within the atria, usually sparing internodal conduction. In electrically driven hearts, direct recording of His bundle potential as well as surface electrograms revealed marked prolongation of intraatrial and intranodal conduction times, with some increase in His-Purkinje and ventricular conduction times. Depression of atrioventricular conduction was insignificant under sinus rhythm. Possible therapeutic implications of these electrophysiologic effects are discussed.
采用细胞内微电极技术，在离体兔心以及犬或兔的心脏组织中研究了盐酸乙胺碘呋酮（双律定）的电生理效应。除了将乙胺碘呋酮直接加入组织浴的实验外，所用浓度范围为0.25 - 10 mg/L。乙胺碘呋酮在不影响动作电位外形的浓度下，可降低窦房结、房室交界区和浦肯野纤维的自律性。在心房和心室纤维中，乙胺碘呋酮可延长动作电位时程和总不应期。动作电位的上升速率减慢，传导时间延长。较高浓度可降低静息电位，导致不完全去极化。心房动作电位比心室和浦肯野动作电位在更低浓度时就受到影响。偶尔，乙胺碘呋酮可在心房内产生局部传导阻滞，通常不累及结间传导。在电驱动的心脏中，直接记录希氏束电位以及体表心电图显示，心房内和结内传导时间显著延长，希氏 - 浦肯野纤维和心室传导时间也有所增加。在窦性心律下，房室传导的抑制作用不明显。文中讨论了这些电生理效应可能的治疗意义。
