Muscle Metaboreflex-Induced Increases in Effective Arterial Elastance: Effect of Heart Failure.

Muscle Metaboreflex-Induced Increases in Effective Arterial Elastance: Effect of Heart Failure. Am J Physiol Regul Integr Comp Physiol. 2020 Apr 29;: Authors: Mannozzi J, Kaur J, Spranger MD, Al-Hassan MH, Lessanework B, Alvarez A, Chung CS, O'Leary DS Abstract Dynamic exercise elicits robust increases in sympathetic activity in part due to muscle metaboreflex activation (MMA) - a pressor response triggered by activation of skeletal muscle afferents. MMA during dynamic exercise increases arterial pressure by increasing cardiac output via increases in heart rate, ventricular contractility, and central blood volume mobilization. In heart failure ventricular function is compromised and MMA elicits peripheral vasoconstriction. Ventricular-vascular coupling reflects the efficiency of energy transfer from the left ventricle to the systemic circulation and is calculated as the ratio of effective arterial elastance (Ea) to left ventricular maximal elastance (Emax). The effect of MMA on Ea in normal subjects is unknown. Furthermore, whether muscle metaboreflex control of Ea is altered in heart failure has not been investigated. We utilized two previously published methods of evaluating Ea: (end systolic pressure รท stroke volume (EaPV)) and (heart rate x vascular resistance (EaZ)) during rest, mild treadmill exercise and MMA (induced via partial reductions in hindlimb blood flow imposed during exercise) in chronically instrumented conscious c...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - Category: Physiology Authors: Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research