title: Does the right muscular atrioventricular valve in the avian heart perform two functions?
abstract: The right atrioventricular valve of adult birds is a muscular unicuspid structure and unlike the right atrioventricular valve in the adult mammalian heart. The aim of this study is to test the hypothesis that the avian muscular valve (MV) is a part of the cardiac wall during systole and contributes to the right ventricle pump function. Six adult hens Gallus gallus domesticus were examined with a focus on MV structure and function. The thickness of the right ventricle (RV) wall and MV were examined post-mortem. RV wall and MV end-systolic thickness were estimated echocardiographically. The frame-by-frame processing of RV images was applied for the analysis of MV and RV free wall motion. According to the post-mortem measurements, no significant difference in the thickness between RV free wall and MV (1.8±0.3 and 1.6±0.4 mm, respectively) was found. In the course of the entire cardiac cycle, MV demonstrated the excursion of 10.3±0.9 mm. To the end of RV systole, MV thickness was increased roughly by a factor of two (2.9±0.57 mm), and reached almost the same value (3.0±0.25 mm) in RV free wall. Based on the findings obtained, we concluded that the MV may play specific and non-specific roles in the avian heart. First, MV determines the blood flow separation between the right heart chambers. Second, MV performs contractility to support for RV pump function.
authors: Institute of Physiology, Komi Science Centre, the Russian Academy of Sciences, 50 Pervomayskaya Street, Syktyvkar 167982, Russia. Electronic address: V.Prosheva@physiol.komisc.ru.
authors: Valentina
authors: V
authors: Prosheva
authors: Institute of Physiology, Komi Science Centre, the Russian Academy of Sciences, 50 Pervomayskaya Street, Syktyvkar 167982, Russia.
authors: Bronislav
authors: B
authors: Dernovoj
authors: Institute of Physiology, Komi Science Centre, the Russian Academy of Sciences, 50 Pervomayskaya Street, Syktyvkar 167982, Russia.
authors: Sergey
authors: S
authors: Kharin
authors: Institute of Physiology, Komi Science Centre, the Russian Academy of Sciences, 50 Pervomayskaya Street, Syktyvkar 167982, Russia.
authors: Natalya
authors: N
authors: Kaseva
authors: Ural State Medical University, 3 Repin Street, Yekaterinburg 620028, Russia; Ural Federal University, 51 Lenin Avenue, Yekaterinburg 620083, Russia.
authors: Tatyana
authors: T
authors: Shklyar
authors: Ural State Medical University, 3 Repin Street, Yekaterinburg 620028, Russia; Ural Federal University, 51 Lenin Avenue, Yekaterinburg 620083, Russia.
authors: Felix
authors: F
authors: Blyakhman
mesh_terms: D000818:Animals; D001717:Birds / Q000502:physiology*; D006325:Heart Atria; D006351:Heart Valves / Q000502:physiology*; D006352:Heart Ventricles
keywords: Avian heart; Echocardiography; Muscular atrioventricular valve mechanics; Post-mortem examinations; Right ventricle structure and function