The Impact of Cardiovascular Diseases on Cardiovascular Regulation During Exercise in Humans: Studies on Metaboreflex Activation Elicited by the Post-exercise Muscle Ischemia Method

Fig. (1). Normal hemodynamic modulation during metaboreflex activated by the post-exercise muscle ischemia (PEMI) method. In healthiness, during PEMI-elicited metaboreflex the functional reserves of three of the four hemodynamic modulators (inotropism, preload and afterload) are recruited, whereas the reserve in chronotropism cannot be investigated. The target blood pressure level is achieved mainly by inotropism and preload adjustments, while little role is played by the reserve in afterload.

Fig. (2). If cardiac contractility and or preload reserves are exhausted during PEMI, the possibility of having a flow-mediated blood pressure increase is precluded. The hemodynamic consequence is that the target blood pressure is reached by recruiting the reserve in cardiac afterload (i.e. systemic vascular resistance increase). In this case, systemic vascular elevation becomes the main mechanism through which cardiovascular reflexes operate to adjust hemodynamics.