I too have suffered a heart attack in October2007 and my EF dropped to 28%.I am on medications and do regular mild level exercises since then as per the advice of my cardiologist.Though there is little improvement in EF over the past year, I have bettered my condition as confidence to lead a near normal life is built by me.
It is very important that your brother feels that he can lead a reasonably good life. Medications, short walks, diet, yoga (correct one) gradually help recover. Please also the get the dose of medications checked by some other doctor.
This forum has many people who have recovered from less than 22% EF. Give details of your brother's medical history. You will get suggestions which will help.