Normal values for left ventricular function tests often refer to LVEF values, i.e., left ventricular ejection fraction, which reflects the left ventricular pumping capacity, i.e., the contractile function of the left heart. When the LV ejection fraction is above 50%, the pumping function of the left heart is considered normal. When the LV ejection fraction is less than 50%, it suggests a decrease in left heart function. Changes in LVEF values allow assessment of heart failure. A normal LVEF value should be ≥50%, and if the LVEF is less than 50% it suggests a reduced ejection fraction and decreased cardiac systolic function. When the LVEF is between 40% and 50%, it is mildly reduced, between 30% and 40%, it is moderately reduced, and <30%, it is severely reduced.The level of LVEF is closely related to the structure and size of the heart, and when the left ventricle undergoes severe deformation, i.e., the left ventricle undergoes obvious enlargement and thinning, the function of the left heart will also be reduced. Cardiac ultrasound can be a good way to check the size and function of the heart, and there is no need to worry too much about a decrease in LVEF, so you should actively seek proper medical care and treat according to the doctor's instructions.