Normal Left Ventricular Ejection Fraction
May 27, 2022
Source: Cainiu Health
Dr. Li Man
Introduction
The normal left ventricular ejection fraction (LVEF) ranges from 50% to 70%. Left ventricular ejection fraction refers to the ratio of cardiac output to left ventricular end-diastolic volume. An LVEF below 50% suggests heart failure, which can be classified into four functional classes according to the New York Heart Association (NYHA) classification system. Class I heart failure indicates the presence of cardiac disease without any limitation on physical activity.
Left Ventricular Ejection Fraction (LVEF): In clinical practice, patients often encounter a value referred to as the “EF value,” which is a key indicator of cardiac function. What, then, constitutes a normal LVEF?
Normal Left Ventricular Ejection Fraction
The normal LVEF range is 50%–70%. LVEF represents the ratio of stroke volume (the amount of blood pumped by the left ventricle in one contraction) to the left ventricular end-diastolic volume (LVEDV). An LVEF below 50% suggests impaired cardiac function—i.e., heart failure. Heart failure severity is commonly classified into four functional classes according to the New York Heart Association (NYHA) classification system. Class I heart failure indicates the presence of structural heart disease but no limitation of physical activity; ordinary physical activity does not cause symptoms such as fatigue, palpitations, dyspnea, or angina.
Class II denotes slight limitation of physical activity: patients are asymptomatic at rest, but ordinary physical activity results in symptoms such as fatigue and palpitations. Class III indicates marked limitation of physical activity: patients are asymptomatic at rest, but less-than-ordinary activity provokes symptoms including fatigue, palpitations, chest tightness, or anxiety. Class IV signifies severe heart failure: patients experience symptoms even at rest and are unable to carry out any physical activity without discomfort.
LVEF is defined as the ratio of stroke volume to left ventricular end-diastolic volume. An LVEF below 50% raises suspicion of cardiac dysfunction. Clinically, the severity of heart failure is assessed using multiple parameters—including the patient’s LVEF, clinical symptoms, vital signs, and findings from ancillary diagnostic tests. We hope this explanation has been helpful!
