Electrocardiographic Changes after Glucose Ingestion

In order to determine the effect of glucose ingestion on the electrocardiogram, 23 men with coronary heart disease and 30 without known heart disease had electrocardiograms in the fasting state and serial tracings at 30-minute intervals after the administration of 100 Gm. of oral glucose. In both groups the mean changes after glucose ingestion were slight ST-segment depression, a moderate decrease in T-wave amplitude, and a slight increase in heart rate, although individual variability was great. When the electrocardiograms were classified by a uniform coding system, new ST-segment or T-wave classifications were recorded for eight of 23 subjects with coronary heart disease and three of 30 men without known heart disease. Since ST-segment and T-wave changes regularly follow glucose ingestion and are sometimes of sufficient degree to suggest heart disease in apparently normal individuals, electrocardiograms recorded within several hours after glucose administration must be interpreted with caution. Because of the uncertain significance of postprandial ST-segment and T-wave changes, electrocardiograms after glucose ingestion do not appear to be a very useful method for the detection of occult heart disease. Glucose ingestion should be avoided before routine clinical tracings.