Does Blood Glucose Have An Effect On Heart Beat Rate?

One year ago, I accidently went to hospital to have check up and found out that my blood glucose is high up to 170 with some urine glucose. The doctor asked me to do only serious exercise for month month and be on diet. The exercise and diet gave good result esp. for the first two weeks and the blood glucose downs to normal range. Until now my fasting blood glucose is still in normal range without any medication. However, the new sumptom has happened for three months is that the "slow down of heart beat sometime in a day esp. at noon and in the everning. To prevent this irregularity I went to the local doctor and he treated me for Flecain for 10 days, but it seems temporarily relief but generally is not effective. Then I stopped using medicine and try to exercise instead (morning and everning) and the heart beating becoming better. The questions are: Whether the slow heart beating relates to history of high blood glucose?; how can I deal with slow heart beating. Please recommend me whatever the best way to solve my heart problem.