A group of 305 patients were studied to evaluate the significance of orthostatic and hyperventilative T-wave changes, orthostatic blood pressure changes, and the relationship of ischemic heart disease, as determined by treadmill stress testing, to these observed changes. The results indicate that orthostatic and hyperventilative T-wave changes are not at all an unusual finding in the younger age group and are not related to ischemic heart disease. In patients having ischemic heart disease, a stationary or decreased systolic blood pressure when changing from a sitting to a standing position was seen in the majority studied. The presence of orthostatic and hyperventilative T-wave changes did not confuse the interpretation of the treadmill stress test electrocardiogram when evaluated by our criteria for ischemic abnormality.
Kemp GL, Ellestad MH. The Significance of Hyperventilative and Orthostatic T-Wave Changes on the Electrocardiogram. Arch Intern Med. 1968;121(6):518-523. doi:10.1001/archinte.1968.03640060032006