The Effect of Insulin Hypoglycemia on the Circulation 1

Several observers have directed attention to the fact that insulin hypoglycemia may precipitate symptoms and signs of serious disturb- ance in the cardiovascular system.Gigon (1), in 1923, reported that a patient with diabetes mellitus had died from myocardial failure after the third dose of insulin.Reinwein (2) observed two patients with diabetes mellitus and circulatory insufficiency in whom the administra- tion of insulin caused a decided increase in the degree of congestive failure.Joslin (3) and Blotner (4) reported cases in which cardiac infarction developed shortly after the administration of insulin, and von Noorden and Isaac (5) observed several patients with coronary artery disease in whom insulin hypoglycemia apparently was the cause of death.Several instances have been recorded in which insulin hypoglycemia precipitated typical attacks of angina pectoris (6, 7, 8).Further evidence of altered cardiac physiology during insulin hypoglycemia is afforded by the electrocardiographic studies of Middleton and Oatway (9) and others.The changes observed consisted of diminished amplitude or inversion of the T-wave.Although the effect of insulin shock on the pulse rate and arterial blood pressure of man has been studied by several investigators (10, 11, 12, 13), but little attention has been paid to the effect of the hypoglycemic state on the minute volume output of the heart.In the only reported measurements, Lauter and Baumann (13), using the ethyl iodide method of Henderson and Haggard ( 14), recorded an increased circulatory minute volume during hypoglycemia in five