Cardiac Contractility Assignment Example | Topics and Well Written Essays - 250 words

Cardiac Contractility - Assignment Example In a scenario, where there is excessive blood loss to an extent that compensatory mechanism cannot maintain sufficient venous return, a decrease in venous return results in the decreased cardiac output. As heart not able to meet the body requirement, the condition is known as a cardiac failure. Following graph (fig.8) represents the interaction of Frank-Starling and venous return curves. Â  While plotting variables on this Model graph it is assumed that factors affecting another curve such as arteriolar or venous constriction are eliminated. It will affect the predicted values by shifting or alternating the curves above or below normal. For example, while discussing the scenario of blood loss it was highlighted that compensatory mechanisms have failed to restore normal cardiac output. It is important because, during initial blood loss, compensatory mechanisms such as sympathetic vasoconstriction can decrease venous compliance and restore adequate venous return. The factors causing an increase in contractility work by causing an increase in intracellular calcium ions (Ca++) during contraction.