Dynamic Narrowing of the Diaphragmatic Vena Cava in Ovis aries

• DOI: 10.1111/ahe.13114
• Publication Date: 2024-10-15T08:10:57Z
• Authors: William E. Schwar...; Mackenzie E. Turner; J. Logan Spiess; Michael Jimenez; Tatsuya Watanabe; Rikako Hama; Jingru Che; Gracie L. Kelly; Asigul Yimit; Peter B. Baker; Carmen Arsuaga‐Zo...; John Kelly; Christopher K. Br...; Cameron A. Best; James W. Reinhardt
• Keywords: Diaphragm (acoustics); Ovis; Hydrostatic pressure; Venous return curve

ABSTRACT Dorset sheep ( Ovis aries ) are common models in translational cardiovascular research due to physiologic and anatomic similarities humans. While employing ovine subjects study single‐ventricle physiology, we repeatedly observed position‐based changes central venous pressure (CVP) which could not be explained by hydrostatic (gravitational) effects. Inferior vena cava (IVC) narrowing or compression has been demonstrated numerous species, hypothesised that this phenomenon might explain our observations O. . This aimed characterise position‐dependent morphology of the IVC using catheter‐based hemodynamic dimensional measurements, three‐dimensional MRI reconstruction histological analysis. Baseline measurements revealed a significant reduction dimensions at level diaphragm (dVC) compared abdominal (aVC) thoracic (tVC). We also transdiaphragmatic gradient along IVC, with higher pressures aVC tVC. found variation position fluid status altered haemodynamics. Histological data showed variable muscularity length greater smooth muscle content than These findings will improve understanding baseline help refine experimental protocols facilitate translation clinic.