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Location and functional characterization of the right atrioventricular pacemaker ring in the adult avian heart
Author(s) -
Prosheva Valentina I.,
Kaseva Natalya N.
Publication year - 2016
Publication title -
journal of morphology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.652
H-Index - 74
eISSN - 1097-4687
pISSN - 0362-2525
DOI - 10.1002/jmor.20502
Subject(s) - diastolic depolarization , purkinje fibers , depolarization , anatomy , medicine , atrioventricular node , cardiology , sinoatrial node , interventricular septum , bundle branches , bundle of his , biology , electrical conduction system of the heart , interatrial septum , electrophysiology , atrial fibrillation , electrocardiography , left atrium , heart rate , tachycardia , ventricle , blood pressure
Previous histological studies showed that in addition to a sinus node, an atrioventricular (AV) node, an AV bundle, left and right bundle branches, birds also possess a right AV‐Purkinje ring that is located in the atrial sheet of the right muscular AV‐valve along all its base length. The functionality of the AV‐Purkinje ring is unknown. In this work, we studied the topology of pacemaker myocytes in the atrial side of the isolated chicken spontaneously contracting right muscular AV‐valve using the method of microelectrode mapping of action potentials. We show that AV‐cells having the ability to show pacemaking reside in the right muscular AV‐valve. Pacemaker action potentials were exclusively recorded close to the base of the valve along its whole length from dorsal to the ventral attachment to the interventricular septum. These action potentials have much slower rate of depolarization, lower amplitude, and higher diastolic depolarization than action potentials of Purkinje (conducting) cells. We conclude the right AV‐valve has a ring bundle of pacemaker cells (but not Purkinje cells) in the adult chicken heart. J. Morphol. 277:363–369, 2016. © 2015 Wiley Periodicals, Inc.