[Morphofunctional characteristics of pacemaker formations situated in the atrioventricular valves of the heart].

By the microelectrode technique and the method of electron microscopy multicellular formations responsible for generation of the automatic pacemaker activity were found in the cusps of the atrioventricular valves in the rabbit heart. Cells of different morphological structure were revealed: P-cells, cells of the Purkinje type and transitional cells. These formations have rich innervation, mainly of cholinergic nature. A certain correlation was established between the morphological and electrophysiological characteristics of these cells.