Noninvasive electrogram of the bundle of His

The authors present their own experience with noninvasive recording of the bundle of His electrogram using the technique of computer-assisted averaging of the signal coming from the thorax surface. To make the recording, several progressive design features have been employed in an effort to diminish the effect of disturbing electrical activity. A total of 40 patients were examined noninvasively and invasively at an interval of 24 hours at most. The noninvasive technique yielded an assessable bundle of His electrogram in 22 out of the 39 patients in whom the electrogram had been obtained also invasively, ie, in 56%. Comparison of the values of the H-V interval (ie, conduction by the distal His-Purkinje system) in the above 22 subjects revealed a close correlation between both procedures (r = 0.92). The noninvasive His bundle electrogram to be a promising screening tool to improve the accuracy in the diagnosis of atrioventricular conduction disturbance, and to evaluate the effect of antiarrhythmic drugs on the cardiac conduction system.