Had cath apr8 said ef down to 45% started 12.5 toprolxl. had cmri may4 and ef up to 55%. can low dose betablocker raise ef 10pts in less than 1 month?

Most likely not : LVEF quantification by LV angiogram less accurate, reproducible, user dependent and quality of cath. CMRI clearly shown to be more accurate in assessment of LV, RV strict ion and function. Further your dose of beta blocker so low that it makes it even less likely that the medicine caused an improvement so fast. My guess is cMRI accurate and glad it's the higher #!