If your EF is below normal (55-75%), it is an indiction your heart is not receiving a normal cardiac output. When there is angina (chest pain from ischemia) the heart cells are not receiving enough blood oxygen and can be damaged. When the EF (amount of blood pumped with each heartbeat) is low, the demand must be low for blood oxygen to help protect the heart cells. Exercising will increase the demand for oxygenated blood, and the weak heart is not able to meet the demand so there can be further cell damage.
The appropriate treatment would be to lower the heart's afterload with medication by dilating the vessels, med to increase the heart's contraction, etc. You should see your doctor to rule out any damage to heart cells with the events you relate, and to further exercise would be a risk to avoid. Thanks for sharing and take care.
Hi
Welcome to the MedHelp forum!
If your EF has dropped from 48 to 36, then it is not improving. Before exercising further you must talk to your cardiologist. Maybe you need stenting or bypass surgery to overcome the ischemia to the heart muscles. It is difficult to comment beyond this at this stage. Do consult your cardiologist without delay.
Hope this helps. Please let me know if there is any thing else and do keep me posted. Take care!