Stage B
Stage B or class 2 heart failure is also considered pre-heart failure. At this stage, doctors have found signs of left ventricular dysfunction, but you may feel physically healthy and you may have no symptoms.
People at this stage often have an ejection fraction of 40 percent or less [3]. Ejection fraction (EF) is a measure of the amount of blood your heart pumps with each beat. Your EF is considered normal if it is between 55 percent and 70 percent. It is often measured during an echocardiogram (echo).
Doctors often recommend treatments similar to stage A. In addition, doctors may prescribe an aldosterone antagonist if you have an EF of less than 35 percent to prevent your heart muscle from enlarging. You may require a surgical procedure if you have coronary artery blockage or valve disease.