[Electric stimulation as a means for the diagnosis of atrioventricular conduction disorders]

A patient with 2 : 1-block and right-bundle-branch block is described, who developed a high-degree-AV block distal to the bundle of His during electrophysiological investigations. Rapid atrial pacing caused total AV block distal to the His bundle. Rapid pacing from the right ventricle also caused total AV block after sudden discontinuation of pacing. The duration of total AV block was 25 to 60 seconds and the preautomatic time 2300-4750 msec according to rate and duration of stimulation. These methods are considered as good tools to evaluate patients with severely diseased conduction system, who might develop total AV block or Adams-Stokes seizures.