Billette J
Am J Cardiol. 1976 Dec;38(7):889-96. doi: 10.1016/0002-9149(76)90802-x.
This investigation shows that atrioventricular (A-V) nodal conduction time (A-H interval), both in the human and in the isolated rabbit heart, is determined mainly by the length of the preceding His-atrial (H-A) interval. The A-H intervals obtained during atrial extrasystolic stimulation at different basic rates, during Wenckebach cycles and during both transient and steady state responses to stepwise increases in stimulation frequency were plotted against the corresponding H-A intervals. The A-H intervals were found to have nearly the same duration provided they were preceded by the same H-A interval. The only important difference appeared in the short H-A interval range as a shortening of the A-H interval at faster basic rates. This facilitating effect of frequency, which was found in the majority of cases, is compatible with the similarly frequency-dependent shortening of the functional refractory period of the A-V node.
本研究表明，在人体和离体兔心脏中，房室（A-V）结传导时间（A-H间期）主要由前一个希氏束-心房（H-A）间期的长度决定。将在不同基础心率下进行心房期外刺激时、文氏周期期间以及对刺激频率逐步增加的瞬态和稳态反应期间获得的A-H间期与相应的H-A间期进行绘图。发现只要A-H间期之前的H-A间期相同，其持续时间就几乎相同。唯一重要的差异出现在短H-A间期范围内，即基础心率较快时A-H间期缩短。在大多数情况下发现的这种频率促进作用，与房室结功能性不应期类似的频率依赖性缩短是一致的。
