You can get a lot of background interference with an ECG and usually need several taken to get a proper diagnosis. Your husband should have had blood samples taken to test for cardiac enzymes as these would be a definiate indicator as to whether or not he had a heart attack
. Also echocardiograms can be used to look at the heart tissue and see if it is normal or has muscle abnormality. The heart rate
varies so the ECG will vary and a more thorough diagnosis should give a clearer picture.