体外ヒス束心電図の臨床応用 房室伝導障害例ならびに心房細動例についての検討

抄録

Noninvasive recording of His bundle activity from the body surface by using the signal averaging was attempted in 20 cases of atrioventricular block and 6 cases of atrial fibrillation. As described in the previous report, the R wave in the standard electrocardiogram was used for triggering the signal averaging.
An obvious His bundle activity (G potential) could be recored by noninvasive method in 17 cases of AV block and 3 cases of atrial fibrillation. The G pottential was clearly seen by signal averaging 50, 300 and 400 cardiac cycles in first and third degree AV block and atrial fibrillation respectively. The simultaneous appearance of the G potential with the H deflection in routine His bundle electrogram was confirmed in 6 cases. Three cases of third degree AV block, in which the noninvasive recording of the His bundle activity was not successful, were confirmed to be H-V block by routine invasive examination. The reproducibility of the G potential was excellent in 2 cases, in which the reexamination was performed.
The G potential was obvious in only one or some of the precordial leads in several cases. Therefore, multiple leads across the chest should be performed in order to record the potential. Multiple leads were also necessary for precise determination of the onset of the ventricular activation, although the anteroposterior lead usually yielded the earliest QRS complex.
The noninvasive recording of His bundle electrogram is safe and useful diagnostic method for determination of the site of block in atrioventricular conduction disturbance, although our present recording method is of limited value, because the recording of the G potential is theoretically impossible in second or third degree H-V block.