- End-diastolic volume
In
cardiovascular physiology , end-diastolic volume (EDV) is the volume ofblood in a ventricle at the end of filling (diastole ). Because greater EDVs cause greater distention of the ventricle, "EDV" is often used synonymously with "preload", which refers to the length of thesarcomere s incardiac muscle prior to contraction (systole ). An increase in EDV increases the preload on the heart and, through the Frank-Starling mechanism of the heart, increases the amount of blood ejected from the ventricle during systole (stroke volume ).Because nearly two-thirds of the blood in the
systemic circulation is stored in the venous system, end-diastolic volume is closely related to venous compliance. Increasing venous compliance elevates thecapacitance of the veins, reducing venous return and therefore end-diastolic volume. Decreasing venous compliance has the opposite effect. For example, activation of thebaroreceptor reflex (occurring, for instance, in acutehemorrhage ) causesvenoconstriction , which decreases venous compliance, improves venous return, and therefore increases end-diastolic volume.ee also
*
End-systolic volume
*Stroke volume
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