[The relation between the electrophysiological parameters of the right atrium and the AV-node conduction (author's...

40 patients were examined with the extrastimulus method at 3 different driving rates (80, 100 and 120/min). It was found that the atrial conduction velocity during the relative refractory period sometimes explains a paradoxical conduction of a premature atrial beat. The AV-node conduction is mainly determined by the correlation between the functional refractory period of the right atrium (FRPRA) and the effective retractory period of the AV-node (ERPAVN). With increasing driving rate the FRPRA shortened while ERPAVN lengthened. This explains why in this study the number of patients in which the ERPAVN could be reached progressively increased from 23 at a driving rate of 80/min to 31 and 33, respectively, at the driving rates of 100 and 120/min.