[Examination of sinoatrial conduction through premature atrial stimuli via the esophagus].

Sinoatrial (SA) conduction can be tested in man by premature atrial stimuli. The difference between the post-extrasystolic pause and the spontaneous sinus cycle is a sign of the sinoatrial delay. Extern atrial stimuli provoked over the esophagus showed analogous results to intracardiac tests. The sinoatrial conduction time estimated by the esophagus method is about 20 ms higher. In 30 normal persons it was 95 +/- 36 ms (x +/- 2 SX). 7 patients with sick sinus syndrome showed aberrations as in the intracardiac test. Different types of sinoatrial block should be distinguished. Type I measured by the esophagus method had a "SAE time" over 130 ms. Type II always had compensating postextrasystolic pauses due to higher SA delay. Type III of other authors could not be observed; there are doubts about the rightness of this type. In 2 patients SA blocks over several sinus cysles could be induced by premature stimuli. This feature osberved for the first time has been declared as type IV. In 28 patients with different diseases of the heart type I could be found 12 times and type II 6 times; SA block was not known previously. The calculation of the SA time by atrial stimuli via the esophagus offers a riskless and simple method for the further differential diagnosis of disturbances of the cardiac rhythm.