Dear all I had one adult male patient agaed 65yrs a newly diagnosed diabetic with Blood sugar value of 350mg% admitted for sugar control and started on OHA suddenly developed breathlessness 36hours after admission while in toilet which increased on eating with BP of 210/120mmHg(he was normotensive earlier),his ECG was normal on admission and at the time of insult and CXR,LFT,LIPID. PROFILE,ELECTROLYTES and urea and creatinine were normal.Resuscitated but he collapsed.

What is the cause and what could have I done? Please Give your opinion