Why would an lvef of 46% cause a "borderline" ekg (treadmill) reading? bp 110/70, hr 44, no dilation or thickening (mri), calcium score negative, hear

Detailed history: It sounds like you have already had extensive testing. These little text boxes are not big enough to go through all the details, which is what a doctor would need to be able to help. You might consider a second opinion inbox consult here on HealthTap where you can share the records of your tests and have them reviewed. Each heart test adds a different part of the puzzle.