I Have An Icd..several Heart Attacks That Were Discovered During

I have an icd..several heart attacks that were discovered during heart cath..this was 4yrs. ago..my ejection fraction was 33..then 2yrs. later it was35..another was 41..now they are saying it's 61..but dr. wants to see me because of some abnormalities..I also had heart failure 4yrs ago..I want to know if the ejection fraction at 61 could be wrong& who determines this they told me the tech did,which I believe is wrong.