What Causes Night Mares Along With Rapid Heart Rate?

I am 45 year old male. I have been waking up for unknown reasons at night best way I can describe feeling Scared or dreaming but symptoms seizure like and heart racing Bit. Waking as if I am having a bad dream. It may only occur once or twice a week and multiple times during the night when it does occur. I take no meds. and never have had seizures but have had anxiety and stress issues periodically throughout last several years. I am in fair to good health but do have high hdl and Blood sugar. I work out 4 days a week. but stress and anxiety of late has been elevated could be cause Not sure but bit nervous