Heart Failure Index What Is Normal

The normal range for clinical ejection fraction (EF) is between 55% and 75%. When EF drops below 50%, it may indicate abnormal systolic function. If EF falls below 40%, it can be diagnosed as systolic dysfunction heart failure. Normally, the ventricular volume is around 120ml, and the heart pumps out approximately 60-70ml with each beat. For example, if the ventricle ejects 60ml of blood and the maximum end-diastolic volume is 120ml, the ejection fraction would be calculated as 50%.

Understanding Ejection Fraction

Ejection fraction is a key indicator used by doctors to assess heart function. It measures the percentage of blood that is pumped out of the left ventricle with each heartbeat. A healthy heart efficiently ejects more than half of the blood in the ventricle during contraction. When this number declines, it could signal heart failure or other cardiac conditions.

How Is Ejection Fraction Measured?

Ejection fraction is typically measured using an echocardiogram (heart ultrasound). This non-invasive test provides detailed images of the heart's chambers and valves, allowing doctors to evaluate the heart's pumping capacity. During the cardiac cycle, the heart goes through phases of relaxation and contraction.

In the early phase of ventricular relaxation, known as isovolumetric relaxation, the volume remains constant while pressure inside the ventricle drops significantly. As pressure decreases, the mitral valve opens, allowing blood to rapidly fill the ventricle from the atrium. Eventually, the pressures in the ventricle and atrium equalize, prompting the atria to contract and push additional blood into the ventricles—this is referred to as the end-diastolic phase.

The Cardiac Cycle Explained

At the end of diastole, when the left ventricle is filled to its maximum capacity, the ventricle begins to contract again. This contraction forces blood into the aorta and out to the rest of the body. This cycle repeats with every heartbeat and is essential for maintaining proper circulation and oxygen delivery throughout the body.

Monitoring ejection fraction is crucial for patients with heart conditions, as it helps guide treatment and assess disease progression. Regular check-ups and appropriate medical care can significantly improve outcomes for those with reduced ejection fraction.