What does 25 % of heart working mean

What does

Your doctor should have explained this to you. You have heart failure, or on the verge of it, which is a serious condition. You can get winded VERY easily, are subject to angina, edema (pulmonary and peripheral), and a host of other problems. This needs to be treated very seriously. What other health problems do you have that lead up to this? Diabetes, high blood pressure?