Hi welcome to HCM. .
You have no diabetis ,so one cause has been ruled out .....
Second if you are using diuretic drug for cardiac problem like HT, LVH then more urination can occur ....
If you have cystitis then also can be cause . .
You have not mentioned your gender ....
If you are male then prostate enlargement checked by per
rectal examination....
If you are female and darkening of nipple ,
menstruation not comed, sore nipple, fatigue present then pregnancy has to be ruled out by Hcg estimation and USG ....
If suspecting bladder wall muscle problem or nerve problem then
cystometry and neurological examination done ....
If needed
cystoscopy done ....
If excess water drinking there or excess stress then also affect urination....
Consult nephrologist for detail history and examination....
Caffeine, chocolate, alcohol etc restricted ...
Take care