Hemodynamic Function of the Right Ventricular-Pulmonary Vascular-Left Atrial Unit: Normal Responses to Exercise in Healthy Adults.

Hemodynamic Function of the Right Ventricular-Pulmonary Vascular-Left Atrial Unit: Normal Responses to Exercise in Healthy Adults. Am J Physiol Heart Circ Physiol. 2020 Dec 24;: Authors: Wright SP, Dawkins TG, Eves ND, Shave RE, Tedford R, Mak S Abstract With each heartbeat, the right ventricle (RV) inputs blood into the pulmonary vascular (PV) compartment which conducts blood through the lungs at low pressure and concurrently fills the left atrium (LA) for output to the systemic circulation. This overall hemodynamic function of the integrated RV-PV-LA unit is determined by complex interactions between the components that vary over the cardiac cycle but are often assessed in terms of mean pressure and flow. Exercise challenges these hemodynamic interactions as cardiac filling increases, stroke volume augments, and cycle length decreases, with PV pressures ultimately increasing in association with cardiac output. Recent cardio-pulmonary exercise hemodynamic studies have enriched the available data from healthy adults, yielded insight into the underlying mechanisms which modify the PV pressure-flow relationship, and better delineated the normal limits of healthy responses to exercise. This review will examine hemodynamic function of the RV-PV-LA unit using the 2-element Windkessel model for the pulmonary circulation. It will focus on acute PV and LA responses that accommodate increased RV output during exercise, including PV recruitmen...
Source: American Journal of Physiology. Heart and Circulatory Physiology - Category: Physiology Authors: Tags: Am J Physiol Heart Circ Physiol Source Type: research