[Endocavitary electric exploration in the study of auricular dysrhythmias].

His bundle recording combined with atrial pacing permit to evaluate atrio-ventricular conduction and the function of the sinus node by measuring the corrected sinus recovering time (CSRT). Three groups of 10 patients are included in this study: -- Group I is composed of control patients; the CSRT varies between 30 and 450 msec (mean value : 320 msec +/- 123.3). Neither atrio-ventricular nor intraventricular block was observed during His bundle recording combined with atrial pacing. -- Group II, composed of patients with atrial dysrhythmia has a CSRT varying from 720 to 5.900 msec (mean value: 2.750 msec +/- 184.5). Six of these patients have atrio-ventricular conduction disturbances. -- In group III all patients had atrio-ventricular or intraventricular conduction defects without atrial dysrhythmia. CSRT varies between 205 and 510 msec (mean value: 310 +/- 88.6). The authors conclude that atrial dysrhythmia is probably an original degenerative disease which is different from the "Lenègre" disease, by his incidence, the location of the lesions and the clinical issue. This conclusion is made by comparing the results of the authors with the analysis by James of the embryogenesis of the sinus node and of atrial and atrio-ventricular pathways.