Myocardial dysfunction in diabetes mellitus is reversed by proper correction of metabolic changes. To assess the role of hyperglycemia on cardiac dysfunction, 50 g of dextrose were intravenously infused to 15 subjects with stable type 2 diabetes. Echocardiographic measurements were made at 0, 60, 120, 180, and 240 minutes. In spite of the high levels of blood glucose reached in diabetics, left ventricular ejection fraction, fractional shortening, and stroke volume did not experience significant changes. Moreover, cardiac output significantly (p less than 0.01) increased in diabetics secondary to an increase in heart rate. No cardiac changes were noticed in 7 healthy subjects studied in a similar fashion. However, their induced hyperglycemia was not as elevated as in the diabetic patients. These results suggest that acute induced hyperglycemia per se does not appear to impair left ventricular contractility in diabetics at resting conditions.