Your doctor increased the ACE inhibitor dose because of the low ejection fraction. The increased does will hopefully help strenghten your heart muscle and improve the ejection fraction. The diastolic dysfunction was probably there previously, but not commented upon.
James
They are proven effective against cardiomyopathy, may be easier to tolerate, and may be effective in lower doses.
I am personally a believer in ALTACE after taking it for three months.