Ventricular ectopic heart beats are very common, nothing to do with diabetes itself. They are when one beat comes very early, so there is a longer gap before the next one. If you check your own pulse on your wrist you will know if you have one because it feels like a missed beat. Unless they come one after the other after the other frequently, they are usually harmless. There is plenty of stuff about them on the internet. I know because I had them, picked up on an ECG like you. Mine went of their own accord, although I get an odd one every now and again. At the time I had them my diabetes was in remission and all my excess weight had long gone, so I know it was nothing to do with that.