Elastic characteristics of isolated segments of human aortas under dynamic conditions

¹ U.S. Naval Air Development Center, Aviation Medical Acceleration Laboratory, Johnsville, Pennsylvania

When isolated segments of human descending thoracic aorta were caused to change their volume rapidly and continuously in sinusoidal fashion with pulse pressures and pulse rates maintained in the physiological range, the resulting pressure-volume curves showed slight but consistent increases in stiffness, compared to pressure-volume curves obtained on the same specimens when inflated stepwise. There was introduced into the pressure measuring system a time lag of sufficient magnitude to eliminate the hysteresis loop. The extent of hysteresis in the aorta was not determined because time lags in the aorta could not be distinguished from time lags in the measuring equipment.