End-Systolic Volume
Overview
End-systolic volume (ESV) is a term used in cardiology to refer to the volume of blood in the left ventricle of the heart at the end of systole, the contraction phase of the cardiac cycle. It is a key parameter in the assessment of cardiac function, particularly in the evaluation of left ventricular systolic function.
Physiology
The normal range for ESV in a healthy adult is between 50 and 100 milliliters. This volume represents the amount of blood that remains in the left ventricle after the heart has contracted to pump blood out into the body. The ESV is inversely related to the strength of the heart's contraction - a lower ESV indicates a stronger contraction and more efficient pumping of blood.
Measurement
ESV can be measured using various imaging techniques, including echocardiography, cardiac MRI, and computed tomography (CT). These techniques provide a visual representation of the heart's structure and function, allowing for the accurate measurement of ventricular volumes.
Clinical Significance
Alterations in ESV can be indicative of various cardiac conditions. An increased ESV may be seen in conditions such as heart failure, where the heart's ability to pump blood is compromised. Conversely, a decreased ESV may be seen in conditions such as hypertrophic cardiomyopathy, where the heart muscle is abnormally thickened.
Factors Influencing ESV
Several factors can influence the ESV, including heart rate, blood pressure, and the contractility of the heart muscle. Medications such as beta blockers and calcium channel blockers can also affect the ESV by altering the heart's contractility.