My dad's heart is only working at 20 percent what does this mean

Cardiomyopathy: If he was told his left ventricular ejection fraction is 20%, it means his heart's function is severely diminished. A normal ejection fraction is 50% or greater. However, modern medications can help improve ones ejection fraction and, even in cases wherein the ejection fraction does not improve, one's symptoms can be improved dramatically with medical therapy. A cardiologist can often solve thi