The effect of continuous subcutaneous insulin infusion on cardiac performance during exercise in insulin-dependent diabetics

Abstract

To assess the effects of improved glycaemic control on the right and left ventricular ejection fraction (RVEF and LVEF), we performed radionuclide angiocardiography at rest and during exercise in nine insulin-dependent diabetics with a diabetes duration between 2 and 35 years (mean 12 years) and in 10 control subjects. The diabetics were investigated before and after 7 days' treatment with continuous subcutaneous insulin infusion (CSII). The diabetics had a significantly smaller rise in exercise-induced LVEF during normoglycaemia than in the hyperglycaemic state. In contrast to the control subjects, the diabetics, independent of glycaemic control, did not increase the end-diastolic volume and did not decrease the end-systolic volume during exercise. Our data indicate a preclinical abnormal left ventricular function in young diabetics without long-term diabetic complications. The dysfunction seems unrelated to changes in the loading of the heart and appears to be caused by decreased contractile reserve of the myocardium.

Key Words:

• ejection fraction
• graded exercise
• heart performance
• radionuclide angiocardiography