In five patients, bundle of His electrograms were recorded during right ventricular pacing at various cycle lengths. In all patients, as the cycle length of stimulation was decreased, the pattern of retrograde conduction proceeded from 1:1 retrograde conduction to retrograde Wenckebach with or without manifest reentry, to retrograde Wenckebach cycles with concealed reentry. The requisite condit...

In five patients, bundle of His electrograms were recorded during right ventricular pacing at various cycle lengths. In all patients, as the cycle length of stimulation was decreased, the pattern of retrograde conduction proceeded from 1:1 retrograde conduction to retrograde Wenckebach with or without manifest reentry, to retrograde Wenckebach cycles with concealed reentry. The requisite condit...

introduction: the aim of the present study was to determine direct effects of no modulation on protective electrophysiological properties of atrioventricular node (av node) in the experimental model of af in rabbit. methods: isolated perfused rabbit av nodal preparations were used in two groups. in the first group (n=7), lname (50μm) was applied. in the second group (n=12), different concentrat...

Two cases of sinus rhythm with ventricular extrasystoles are reported in which extrasystoles arising from the same focus obey the rule of "comcealed bigeminy" and the "rule of bigeminy". In a comparatively rapid sinus rhythm, shortening of the sinus cycle favors the appearance of extrasystoles, and the extrasystoles obey the fule of "concealed bigeminy"; namely, sinus impulses intervene between...

The hand stencils of European Paleolithic art tend to be considered of pre-Magdalenian age and scholars have generally assigned them to the Gravettian period. At El Castillo Cave, application of U-series dating to calcite accretions has established a minimum age of 37,290 years for underlying red hand stencils, implying execution in the earlier part of the Aurignacian if not beforehand. Togethe...