Dear patient , your mother has got long standing
Diabetes mellitus and left ventricular failure due to poor left ventricular function as her EF is only 28% in echocardiography . The cause of poor left ventricular function could be
Coronary heart disease with ischaemic cardiomyopathy, old silent
myocardial infarction (heart attack) though your echo report does not mention any regional wall motion abnormality ,
dilated cardiomyopathy, or
diabetic cardiomyopathy .Coranary artery blockeds are not seen on echocardiography but are seen by coranary angiography .At present your mother requires treatment for left ventricular failure which will include the drugs which your mother is already receiving ,plus the following drugs
Tab lasilactone (frusimide 20+ spironolactne 50) one daily after break fast
Tab digoxin .25 mg one tab daily for 5 days a week 5/7
Tab clopitab 75 mg once daily bed time
Tab imdur sr 30 mg once daily after break fast
Before starting the these drugs the following investigations shold be done ,ECG, Chest X-ray, blood urea, serum creatinine, serum sodium and potassium
More over you should get an cardiologist consultation done