Internal carotid artery blood flow during the Valsalva manoeuvre in man.

In five patients subjected to reconstructive surgery of the internal carotid artery (ICA), postoperative measurements of the ICA blood flow during the Valsalva manoeuvre were obtained by means of an implanted electromagnetic flow probe. ICA blood flow varied rapidly and parallel to the changes in calculated cerebral perfusion pressure during the Valsalva manoeuvre. At the end of the manoeuvre there was no overshoot in arterial pressure, indicating poor baroreceptor function in these patients.