There may be a heart disorder issue as 40 to 45% EF (amount of blood pumped with each heartbeat) and normal is 50 to 70%. Left ventricular hyperkinesis is an impairment of the heart wall movement (weaker contrations) and would explain the lowerer than normal EF. Your EF doesn't indicate any serious damage to your heart muscle, and many people get along very well with a low EF...if and when the EF gets below 30%, there can be a failure of the heart to pump effectively and blood will back up into the lungs causing congested heart failure...that happened to me about 7 years ago, currently my heart is the proper size and an EF of 59% with medication.
You may be asked to have a stress test. The test will observe blood perfusion with a dye injection during an exercise routine, and then observe the resting period in regard to how fast is the recovery period and return to normal as it appears you may have some occluded vessels that are causing chest pain, etc.
Or the doctor may have enough information and know there are occlusions and wlll want to do an angioplasty. The procedure is to run a cath through a vessel into the heart area and if necessary do a stent implant. I have had that procedure and there is no pain or anxiety with the medication provided.
I have occluded vessels and take medication for any chest pain...I take a nitrate pill prior to going to the gym for a workout for the past 7 years. I have a completely blocked LAD and 70% blocked circumflex, and many doctors in the medical community do not do any interventional therapy if medication is effective.
Hope this helps! Thanks for sharing your experience, and if you have any further questions or comments you are welcome to respond. Take care.