My dad has congestive heart failure

My father had myocardial infraction in 2000. Cardiac ECHO in 2010 showed 45% Ejection fraction. Now recent ECHO showed 20% Ejection fraction. The conclusion of Cardiac ECHO report is that Left atrium mildly dilated, Mild basal septal hypertrophy, Severely reduced left ventricular systolic function with severe global hypokinesia, Normal right ventricular systolic function, Grade 1 left ventricular diastolic dysfunction. Last week he has breathing problem, doctor diagnosed congestion in chest and suggest him Lasix ,Digoxin, Aldactona-A. Sir is this a very serious condition??? what should we do??? here is any treatment in medical science to normalize the ejection fraction of heart?? please help me??