You are saying you are already on Lisinopril
and it doesn't seem to have any effect on your Diastolic hypertension
, then let your cardiologist know about this. Unfortunately here on Yahoo Answers we can only advise you on general measures to keep your heart healthier, eg diet and excercise.
Your cardiologist might consider changing your drug group. Lisinopril and Captopril
come from Angiotension-Converting-Enzyme Inhibitors (ACE inhibitors).
The drug group I would actually try you on if I was your cardiologist is called Angiotensin
II Receiptor Antagonists eg Cozaar, Candesartan
Explaining to you how these 2 drug groups differ from each other might be too much for you. Do consult your cardiologist.