I had an EKG and was told i had a Left Bundle Bunch Block, which i didn't have 2 years ago. They then did a thalium stress test and they said my left side of my heart has a perfusion of 44% instead of 55%. Now they want to do a heart cath. Will a LBBB cause this to be observed on a stress test. They say they are checking for blockages. I hav no sypmptoms and had the EKG just because i was getting ready for a knee scope cause i hurt my knee. Please help, i'm kinda scared of this cath, the first DR i saw scared the ---- out of me. Thanks