Low (45) Ejection Fraction in PKD

My daughter (30) has PKD-multiple cysts on Kidney with normal kidney function, cysts on liver.  On Tolvaptan trial for past three months.  Had chest pain with  hospitalization and workup and negative gastroscopy.  Echo neg, EKG within normal limits, Stress test normal but Docs are concerned with low (45) EF. She is functional but tired a lot.
What causes could be assumed for lower EF?

[Michael J. McWilliams, M.D.]

If she does not have blockages, this is categorized as a non ischemic cardiomyopathy (non blockage related cardiomyopathy).  If there are no other apparent causes -- like signficant high blood pressure -- the exact cause is often impossible to know.  Heart function like that often requires treatment with beta blockers and ACE inhibitors.

I am unaware of any cardiomyopathy caused by PKD.

I hope this helps.