As has been suggested it will depend on the cause, many times unknown, and on the people. Realistically, I would not expect any mayor change in her EF before 6 months. And keep in mind that for some people they may not improve.
However she may or may not be alleviated of her symptoms earlier. In some cases, where there are little symptoms, medication can, initially, aggravate those.
Jesus
In the duration of one month, I came to know that my sister is suffering from ,DCM , with EF-20%, . It has been 2 weeks that she started to have medication, So how much time does it takes to improve her condition, plz suggest,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Dilated cardiomyopathy is an enlarged left ventricle and that condition will reduce the EF. Usually that condition develops from an overworked heart and the underlying cause is often high blood pressure from constricted vessels. The higher resistence the heart pumps against causes dcm.
Several years ago, I had dcm and other heart issues...medication that dilate the vessels reduces the resistance, and medication to reduce heartrate has returned the size to normal. EF went from 29% (echo) (cath report stated EF13%) to currently 59%.
To answer whether or not your dcm can be successfully treated depends on the underlying cause.