Abstract
This paper describes a technique for recording the His bundle activity from the body surface in man. Standard electrocardiogram and highly amplified bipolar or unipolar lead across the chest filterd between 80 and 300 Hz were recorded simultaneously in 16 cases. In 9 of these, the His bundle electrogram was simultaneously recorded by routine technique using catheter electrodes. In order to extract the small electrical activity of His-Purkinje system from random electrical noise, the signal averaging was applied. The R wave in the standard electrocardiogram was used for triggering the signal averaging.
There were obvious deflections (G complex) between the atrial and ventricular deflections in the surface lead. This G complex appeared simultaneously with the His bundle activity recorded by routine invasive technique. The G complex was clearly seen in the presence of atrial fibrillation. The G-V interval was exactly identical to the H-V interval in 5 cases, while the G-V was 1-2 msec shorter than H-V in 4 cases. There was a intimate correration between the G-V and H-V intervals (r=+0.995).
From the above results, it was concluded that the recording of the His bundle activity in man from the body surface was possible by using the signal averaging technique.
