Arterial Baroreflex Inhibits Muscle Metaboreflex Induced Increases in Effective Arterial Elastance: Implications for Ventricular-Vascular Coupling

FIGURE 1. Average 1-min steady state hemodynamics from the Controlgroup at rest, exercise (EX), and exercise with muscle metaboreflex activation (MMA) before (white) and after induction of heart failure (gray). Data are reported as means with standard error. Observed data points are overlain on corresponding bar graphs. Statistical significance vs. previous workload is depicted as * and vs. previous condition as † where P < 0.05. (N = 5).

FIGURE 2. Average 1-min steady state hemodynamics from the SADgroup at rest, exercise (EX), and exercise with muscle metaboreflex activation (MMA) before (white) an after SAD (orange) and after induction of heart failure post SAD (red). Data are reported as means with standard error. Observed data points are overlain on corresponding bar graphs. Statistical significance vs. previous workload depicted as * where P < 0.05. Comparisons of the condition of SAD vs. control depicted as † where P < 0.05. Comparisons of the condition of heart failure vs. SAD depicted as ‡ where P < 0.05. (N = 5).

FIGURE 3. (A) Average 1-min steady state values of Effective Arterial Elastance and Stroke Work in the Controlgroup at rest, exercise (EX), and exercise with muscle metaboreflex activation (MMA) before (white) and after induction of heart failure (gray). Statistical significance vs. previous workload depicted * and vs. previous condition as † where P < 0.05. (N = 5). (B) Average 1-min steady state values of Effective Arterial Elastance and Stroke Work in the SADgroup at res, exercise (EX), and exercise with muscle metaboreflex activation (MMA) before (white) and after SAD (orange), and after heart failure induction post SAD (red). Statistical significance vs. previous workload depicted as * where P < 0.05. Comparisons of the condition of SAD vs. control depicted as † where P < 0.05. Comparisons of the condition of heart failure vs. SAD depicted as ‡ where P < 0.05. (N = 5) Data for (A,B) are reported as means with standard error. Observed data points are overlain on corresponding bar graphs.

FIGURE 4. (A) The relative change in Effective Arterial Elastance and Stroke Work in the transition from exercise to exercise with muscle metaboreflex activation before (white) and after induction of heart failure (gray) in the Controlgroup. (B) The relative change in Effective Arterial Elastance and Stroke Work in the transition from exercise to exercise with muscle metaboreflex activation before (white) and after SAD (gray) in the SADgroup. (C) The relative change in Effective Arterial Elastance and Stroke Work in the transition from exercise to exercise with muscle metaboreflex activation in normal animals with SAD (white) and after induction of heart failure post SAD (gray) in the SADgroup. (D) The relative change in Effective Arterial Elastance and Stroke Work in the transition from exercise to exercise with muscle metaboreflex activation in heart failure animals from the Controlgroup (white) and heart failure animals post SAD from the SADgroup (gray). For all panels data are reported as means with standard error where data points are overlain on corresponding bar graphs. Statistical significance vs. the previous state as †where P < 0.05. An N = 5 was used for each bar graph in every…

FIGURE 5. (A) Average 1-min steady state values of central venous pressure from the Controlgroup at rest, exercise (EX), and exercise with muscle metaboreflex activation (MMA) before (white) and after induction of heart failure (gray). Data are reported as means with standard error. Observed data points are overlain on corresponding bar graphs. Statistical significance vs. previous workload is depicted as * and vs. previous condition as † where P < 0.05. (N = 5). (B) Average 1-min steady state values of central venous pressure from the SADgroup at rest, exercise (EX), and exercise with muscle metaboreflex activation (MMA) after SAD (orange) and after induction of heart failure post SAD (red). Data are reported as means with standard error. Observed data points are overlain on corresponding bar graphs. Statistical significance vs. previous workload depicted as * where P < 0.05. Comparisons of the condition of SAD vs. Heart failure SAD depicted as ‡ where P < 0.05. (N = 5).

FIGURE 6. Relationship between ventricular maximal elastance (Emax) and stroke work before (black circles) and after induction of heart failure (white circles) at rest, mild exercise, and muscle metaboreflex activation. A linear regression (dotted line) was performed on these points. and the R2 value are shown on the plot. Error bars depict standard error of the mean in both directions (Data points were calculated from primary data collected in experiments which were reported in Coutsos et al. (2010, 2013) (N = 6).