The physiology of left ventricular pressure fall.

Left ventricular pressure (LVP) fall is the hemodynamic manifestation of myocardial relaxation. This paper reviews the most important aspects of LVP fall and its regulation by load, inactivation and nonuniformity. This regulation is explained in terms of calcium transients and cross-bridge mechanics. Specific effects of systolic pressure on LVP fall and their relation to systolic cardiac function are emphasized. These data constitute a conceptual framework for the analysis of myocardial relaxation in cardiovascular research and in the cardiac patient. Comparison of clinical and experimental data during manipulation of afterload should lead to an improved understanding of relaxation disturbances and to a therapeutic approach which is relevant from the pathophysiological point of view. LVP fall may provide useful and quantitative information on systolic LV function if measurements are performed under different conditions of systolic load.