Physiologic Variations in Venous and Arterial Hemodynamics in Response to Postural Changes at the Thoracic Outlet in Normal Volunteers

The prevalence of upper extremity venous and arterial hemodynamic changes varies substantially in different arm positions. Our data suggest that physiologic anomalies in venous flow across the TO during postural changes are very common, while the absence of finger PPG arterial tracings occur in a very small percentage of the population. Abnormal venous flow across the TO with postural changes should be considered a highly prevalent finding in the normal population, and therefore carries little value in the diagnosis of TO syndrome. On the other hand, absence of arterial waveforms measured at the fingers by PPG testing during positional changes occurs in a small percentage of the normal population, and may represent abnormal compression at the TO in patients with upper extremity symptomatology.