Dear Mr. Hemchandra,
From the history you have typed, I can assume few things:-
She has Irregular heart beat
Blood supply to the heart is not adequate (as is expected in most of the very long standing diabetics)
shows couple of blocks in the blood vessels supplying the heart
Shooting up of her sugars could either be due to:-
Recent change in diabetes
seem to be least likely cause of raised sugars as they are inhaled and not oral.
She also has chronic kidney disease
, which also is common in long term diabetics.
She is getting right treatment. I advise you to keep a regular followup with your physician.