Hello and welcome
It is possible that you have suffered through a episode of Atrial Fibrillation
. These are increased heart rate
and heart feels like pumping really fast. They occur for few minutes to hours and that person feels normal. Good thing is that these condition are well managed with medications like bate-blockers and calcium channel blockers. Consult your cardiologist and get to a diagnosis.
In addition to this as you are a diabetic patent you have to rule out Coronary Heart Disease
. A TMT (treadmill test) may be advised by your doctor.
Hope your got your answer