I would be surprised if an MRI would be inaccurate for LVEF. There is also the issue with mild hypokinesis which can work hand in hand with LVEF. It sounds as though you have electrical issues with your heart so perhaps start with an increase in zinc, sodium and potassium. There is no mention of bundle branch blockages (electrical signal blocks) and so I would start with a change in your diet.
One of the readings could have a large error, let's hope it is the low ef.
Follow up in normal. I think you doctor is confident the low ef is not a critical issue, and in fact you ef may be higher.
I had my follow up appointment today to discuss my MRI results and the doctor said he was very surprised by the drop in my ejection fraction as he was not expecting to see that. He wants to do a holter monitor to see how many PVCs I have as they've found some before, and then repeat the MRI in 6 months. Any suggestions on what could be causing, or questions I should be asking? I am a 26 year old male as background
You noticed that your ejection fraction (EJ) is less from last year to this year [59% to 43%], which is low to begin with. Hypokinesis means that there is some hypomotility (things are moving a bit slower than normal).
It is best that you discuss these findings with your doctor since he/she knows your medical history, what medications you are taking, and find out what your plan of care is based on these recent findings.
Keep us informed and we are here to support you. :-)