Fig. 4.

Documentation of fall in blood velocity with balloon inflation. Individual record (compressed) of arterial catheter pressure, brachial artery velocity, and Finometer blood pressure during mild rhythmic hand gripping. Exercise caused a rapid increase in blood velocity. Balloon inflation caused a fall in blood velocity that recovered with no obvious increase in systemic pressure. With balloon deflation there was a modest reactive hyperemia. Breaks in velocity signal indicate times of image acquisition for diameter measurements and breaks in arterial pressure tracing indicate times for blood sampling.