End-diastolic volume

End-diastolic volume (EDV) is a term used in cardiology to describe the volume of blood in the ventricles of the heart at the end of diastolic filling, just before systole (the contraction of the heart muscle). It is a key parameter in assessing the heart's function, particularly in relation to its pumping efficiency and health. EDV, along with end-systolic volume (ESV), is used to calculate the ejection fraction (EF), a critical measure of heart efficiency.

Physiology

During the diastole phase of the cardiac cycle, the heart ventricles relax and fill with blood. This period of relaxation and filling culminates in the end-diastolic volume. The volume of blood in the ventricles at this point is crucial for determining the subsequent stroke volume (SV) — the amount of blood ejected from the heart during systole. According to the Frank-Starling law of the heart, the stroke volume increases in response to an increase in the volume of blood filling the heart (the end-diastolic volume), up to a point. This relationship underscores the importance of EDV in cardiac function.

Measurement

End-diastolic volume can be measured using various imaging techniques, including echocardiography, cardiac MRI (magnetic resonance imaging), and cardiac CT (computed tomography). Echocardiography, a non-invasive and widely available method, uses ultrasound waves to create images of the heart, allowing for the measurement of EDV and other cardiac parameters.

Clinical Significance

Alterations in end-diastolic volume can indicate various cardiac conditions. An increased EDV may suggest heart failure, cardiomyopathy, or valvular heart disease, as these conditions can impair the heart's ability to pump blood efficiently, leading to an accumulation of blood in the ventricles. Conversely, a decreased EDV may be seen in conditions like dehydration or hemorrhage, where there is a reduction in the volume of circulating blood.

Treatment and Management

Management of abnormal end-diastolic volume focuses on treating the underlying cause. For instance, in the case of heart failure, treatment may include medications such as ACE inhibitors, beta blockers, and diuretics to improve heart function and control blood volume. Lifestyle modifications, including diet and exercise, may also be recommended to improve cardiovascular health.

See Also

• Cardiac output
• Heart failure
• Echocardiography
• Cardiac cycle