Arrhythmia during insulin-induced hypoglycemia in a diabetic patient.

The temporal relationship between the level of blood glucose and the frequency of ventricular premature contractions (VPCs) during 24 hours was examined in a 45-year-old man with diabetes mellitus who was treated with a regular insulin injection. The number of VPCs increased sharply when the blood glucose level fell to about 50 mg/dL while the patient was awake. There was a minimal increase in VPCs during sleep, despite a decrease to 21 mg/dL in the blood glucose level. The insulin tolerance test produced frequent VPCs during hypoglycemia, which was suppressed by glucose administration. Changes in the level of plasma epinephrine correlated well with changes in the frequency of VPCs. These data suggest that increased levels of plasma epinephrine may have played a role in the genesis of VPCs that occurred during insulin-induced hypoglycemia.