Yamada S, Watanabe Y
J Electrocardiol. 1985 Oct;18(4):331-9. doi: 10.1016/s0022-0736(85)80015-7.
In order to determine whether the A-H interval of the His bundle electrogram accurately represents the AV nodal conduction time under various conditions, His bundle and coronary sinus electrograms were recorded in isolated perfused rabbit hearts, with atrial stimulation from eight different sites. The S-A (stimulus to the A wave) interval was significantly longer, whereas the A-H interval was shorter on stimulations from the coronary sinus and the left atrium than on sinus nodal stimulation. Stimulations from the fossa ovalis and right atrial appendage did not significantly alter the A-H interval. The effective and functional refractory periods of the AV node were almost identical with stimulations from the sinus node, low right atrial appendage, low left atrial appendage or the ostium of coronary sinus. Mapping of the excitation process with microelectrodes revealed that the activation times in low interatrial septal fibers bordering the His bundle [abbreviated as AP(III)] was closest to the A wave as compared with the activation in the ostium of the coronary sinus [AP(I)] or near the AN region [AP(II)] on stimulation from both sinus nodal and coronary sinus regions. On sinus nodal stimulation, AP(III) preceded AP(I) and AP(II) but lagged behind the A wave by 6 msec, whereas AP(III) preceded the A wave by 5 msec on coronary sinus stimulation. Thus, the A-H interval may not always accurately represent the intranodal conduction time, as relative timing of atrial activation responsible for the A wave and that of invasion of the AV node by the atrial wavefront can be grossly altered by different atrial excitation patterns.
为了确定希氏束电图的A-H间期在各种情况下是否准确代表房室结传导时间，在离体灌注兔心脏中记录希氏束和冠状窦电图，心房刺激来自八个不同部位。与窦房结刺激相比，来自冠状窦和左心房的刺激时，S-A（刺激至A波）间期显著延长，而A-H间期较短。来自卵圆窝和右心耳的刺激未显著改变A-H间期。房室结的有效不应期和功能不应期在窦房结、右心耳下部、左心耳下部或冠状窦口刺激时几乎相同。用微电极绘制兴奋过程表明，与来自窦房结和冠状窦区域的刺激时冠状窦口[AP(I)]或房室结区附近[AP(II)]的激活相比，靠近希氏束的房间隔下部纤维[简称为AP(III)]的激活时间最接近A波。在窦房结刺激时，AP(III)先于AP(I)和AP(II)，但比A波滞后6毫秒，而在冠状窦刺激时，AP(III)比A波先出现5毫秒。因此，A-H间期可能并不总是准确代表结内传导时间，因为引起A波的心房激活的相对时间以及心房波前对房室结的侵入时间可能会因不同的心房兴奋模式而发生显著改变。
