Hello, Not always. It depends upon whether the part of the heart for which we are opening the blood vessels by bypass is living or dead. If that part of heart is living then the chance is there, that heart function will improve to certain extent otherwise not. The test will tell us this information is either pet scan or thallium scan. You discuss these issues with your doctor. Also the ICD or CRT device will be lifesaving here, so also discuss this also with your local doctor. You should have a healthy lifestyle like avoiding fatty, oily and high calorie diet. Have low salt diet and monitor blood pressure regularly. Regular exercises like brisk walking, jogging according your capacity at least 30 min a day and 5 days a week. Eat lots of green leafy vegetables, fruits, fish once or twice a week, avoid meat. Avoid smoking and alcohol if any. There shouldn t abdominal fat deposition or obesity. Get your lipid profile and sugars tested once. Hope I have answered your query. Let me know if I can assist you further. Regards, Dr. Sagar Makode