Arterial-ventricular coupling: mechanistic insights into cardiovascular performance at rest and during exercise.

Chantler PD, Lakatta EG, Najjar SS. Arterial-ventricular coupling: mech- anistic insights into cardiovascular performance at rest and during exer- cise. J Appi Physiol 105: 1342-1351, 2008. First published July 10, 2008; doi: 10.1 152/japplphysiol.90600.2008.-Understanding the performance of the left ventricle (LV) requires not only examining the properties of the LV itself, but also investigating the modulating effects of the arterial system on left ventricular perfor- mance. The interaction of the LV with the arterial system, termed arterial-ventricular coupling (E_AE_LV), is a central determinant of cardiovascular performance and cardiac energetics. E_AE_LV can be indexed by the ratio of effective arterial elastance (E_A; a mE_Asure of the net arterial load exerted on the left ventricle) to left ventricular end-systolic elastance (E_LV; a load-independent mE_Asure of left ventricular chamber performance). At rest, in hE_Althy individuals, E_AE_LV is maintained within a narrow range, which allows the cardiovascular system to optimize energetic efficiency at the expense of mechanical efficacy. During exercise, an acute mismatch between the arterial and ventricular systems occurs, due to a disproportionate incrE_Ase in ELy (from an average of 4.3 to 13.2, and 4.7 to 15.5 mmHgn ~m2 in men and women, respectively) vs. E_A (from an average of 2.3 to 3.2, and 2.3 to 2.9 mmHg mI~ m2 in men and women, respectively), to ensure that sufficient cardiac performance is achieved to meet the incrE_Ased energetic requirements of the body. As a result E_AE_LV decrE_Ases from an average of 0.58 to 0.34, and 0.52 to 0.27 in men and women, respectively. In this review, we provide an overview of the concept of E_AE_LV, and examine the effects of age, hypertension, and hE_Art failure on E_AE_LV and its components (E_A and ELy) in men and women. We discuss these effects both at rest and during exercise and highlight the mechanistic insights that can be derived from studying E_AE_LV. [ABSTRACT FROM AUTHOR]