Unfortunately heart attacks occur in the most fit of individuals. We are now learning that heart attacks like yours don't necessarily take place in areas of biggest blockages in the arteries around the heart, instead they hapen in areas with mild amount of blockage. We now know that inflammation plays a large role in developing the type of heart attack that you had, and cholesterol is very tightly linked to that. A cholesterol level of 240 is significantly elevated. More importantly, however, the LDL cholesterol and sometimes HDL cholesterol is what we are more interested in now. It is very important that now, after your heart attack, your LDL be close to 70 and your HDL as high as possible. You must be on medications called statins (LIpitor, Zocor, Crestor) regardless of your cholesterol level because they have been shown to also work on inflammation. The fact that you are breathless when you exercise may mean many things. The most likely explanation after a heart attack like your is such that your left ventricle suffered some losses and is not as strong as it used to be. Some of the cells in that part of the heart died, and since heart muscle can't regrow after such injury, that whole area of the heart is now replaced by scar. The scar, unfortunately, does not pump blood well, leading to poorer performance of your heart and as a consequence development of the symptoms that you have described. Taking the altace and the lopressor will help your heart get better, however, your symptoms of exertional dyspnea or breathlessness are unlikely to resolve. As far as your exercise is concerned, I would definitely slow down to a point where you are more comfortable during your exercise. It sound like the elliptical machine does not cause you any significant symptoms and you should continue with that at a low pace. Climbing up two flights of stairs is quite a workout and in your case it means that it is probably too intense. If you slow down a little you might be able to tolerate the stairs better. You may want to participate in a cardiac rehabilitiation program. The specialist there take you through a workout routine and educate you what is right or wrong. Discuss this with your cardiologist. He may do an echocardiogram to evaluate your heart function and maybe adjust your medications. Sometimes cardiologist elect to do a stress test to get an objective assessment of your overall functional status. Also, you must be on a statin as I mentioned before.