Paramedic Erik Testerman has generously donated several excellent teaching ECGs to the Guru, and we will be featuring all of them soon. This week, we show you the ECGs from a 59-year-old man with a blood glucose of 30 mg/dl. He had no complaints . After a bolus of Dextrose 10%, his blood glucose was 105 mg/dl. He gave a past medical history of diabetes mellitus, hypertension, and left bundle branch block. Vitals were reported as normal and stable, except for the slow heart rate.