To assess the influence of glucose ingestion on resting and exercise electrocardiograms, 35 subjects were tested after ingestion of a glucose solution and a placebo on separate days. Graded submaximal exercise tests (GXTs) were performed to 90% predicted maximal heart rate. Computer-processed ECGs taken at rest showed a decrease in T-wave amplitude, more ST-segment depression, increased R-wave amplitude, and increased heart rate after glucose. Minnesota code classifications of these same ECGs were more abnormal after glucose. Computer-processed exercise ECGs showed a decrease in T-wave area after glucose ingestion during and after exercise. ST-segment area showed the most variability at one minute after exercise. Three subjects had normal exercise ECGs after placebo and abnormal ECGs after glucose ingestion (ST area >7.5μv/sec). Both resting and exercise ECGs should be made fasting to avoid this significant source of variability.
Riley CP, Oberman A, Sheffield LT. Electrocardiographic Effects of Glucose Ingestion. Arch Intern Med. 1972;130(5):703-707. doi:10.1001/archinte.1972.03650050031005