Take a breath! It will be okay. If they find a blockage, they can do angioplasty, and insert a stent. I stent will keep the blocked area open. You should feel lucky that they are finding a possible blockage BEFORE he had a heart attack. My 52 year old husband has had 2 heart attacks, and he has 6 stents. He works, and is just like he was before the heart attacks (he had no lasting heart damage). The stent will actually make him feel better. He will probably be on a statin (for cholesterol, aspirin, a blood thinner - probably Plavix, and a beta blocker). If he smokes, he will have to quit (well at least that is what the cardio's will want). He should have a low fat diet, and exercise according to his doctors recommendations). He will be fine. You may want to do some research on medicated and non-medicated stents - there has been a great deal of controversary about medicated stents recently. Good luck - and try not to worry about him.