I had an echocardiogram and a stress echocardiogram a month and a half ago which showed my LV ejection fraction being about 65-70 % at rest. I had an mri 3 weeks after that and my LV ejection fraction was 50%. Any thoughts why? I was given xanax before the MrI, as well as flecainide and metropolol. I dont know if the xanax would affect it that much.