Continuously Recorded Changes of Thoracic Aortic Blood Flow in Man in Response to Leg Exercise in Supine Position.

Hir • Much is known of the cardiovas responses of normal man to le; but the available data on blood been obtained during relatively s Until recently, there has not b< factory method for continuously ing changes in thoracic aortic bloi man for significant periods of ti during, and after the changing caused by exercise: Thus, the actual alterations in aortic blood flow at the onset of exercise and during exercise have not previously been recorded. The constant-rate indicator-dilution technic is a satisfactory method for such purposes and was used in this study as previously described and validated by Grace et al. 1 and Marshall et al. 2 Thoracic aortic blood flow was measured before, during, and after approximately six minutes of single-leg exercise on a bicycle ergometer in five healthy male subjects in the supine position. Methods Each of the five healthy male subjects, ages 26 to 34, lay supine on a padded fluoroscopic liloom temperature was kept constant eters were inserted percutaneously, 3 ~ ere attached to each catheter ee-way stopcocks as illustrated 85-cm, number 5, birdseye was inserted percutaneously nedian basilic vein and advanced vena cava. This was attached uge manometer and a pneumatic to make sudden, single injections of Coomassie blue dye. The movement of the plunger of the syringe was recorded by means of a linear potentiometer so that the time and volume of the dye injection could be recorded. A 20-gauge thin-walled needle was inserted into the left radial artery and connected to a strain-gauge manometer, 3 a cuvette-oximeter 4 assembly , and a constant-rate infusion-withdrawal pump.t Through a 19-gauge thin-walled needle inserted into the left brachial artery, an 80-cm, radiopaque polyvinyl catheter (I.D. 0.55 mm, O.D. 0.8 mm) was advanced so that its tip was in a position in .the aorta near the subclavian artery. The catheter was connected to a strain-gauge manometer. Through a 17-gauge thin-walled needle inserted into the left femoral artery, a 27-cm nylon catheter (I.D. 0.9 mm, O.D. 1.2 mm) was advanced to a position near the aortic bifurcation. This catheter was attached to a strain-gauge manometer, to a cuvette-oxi-meter assembly, and to a constant-rate infusion withdrawal pump.t Through a 19-gauge thin