I have reduced heart function following an mi. Most things seem easy to do and I forget and become very tired after exercise or activity. The most puzzling of affects involves a side to side arm motion, this gives me slight chest pain that doesn't make rational sense. Such activity as pulling a weed, working a saw and especially running the vacuum will tire me for hours. I never took naps but the end result of these tasks is often a long nap. The lower part of the heart is damaged, the functional flow rate is about 45 percent. Is there something else I need to have looked at? Age 54 5'8". 180 I walk two miles per day most days. I was walking two hours daily but the doctor said to stop due to fatigue.