The Journal of Thoracic and Cardiovascular Surgery, Vol 80, 888-897, Copyright © 1980 by The American Association for Thoracic Surgery and The Western Thoracic Surgical Association
Measurements of coronary reactive hyperemia with a Doppler probe. Intraoperative guide to hemodynamically significant lesions
CB Wright, DB Doty, CL Eastham and ML Marcus
The physiological significance of coronary obstructions of intermediate
severity are difficult to assess from the angiogram alone. The hemodynamic
significance of clinical coronary stenoses can be readily assessed,
however, with a miniaturized Doppler probe developed at The University of
Iowa Hospitals and Clinics to measure phasic coronary velocity. No
dissection of the coronary vessel is required. The probe is held in place
over the coronary vessel with a small suction cup. Reactive hyperemia
responses obtained following a 20 second occlusion clearly demonstrate the
hemodynamic significance of a coronary stenosis. We have employed this
approach in 64 patients with coronary artery disease. In 12 (19%) in whom
the degree of stenosis of the vessel was equivocal (diameter narrowing 25%
to 70%), the use of the Doppler probe and a 20 second reactive hyperemia
curve allowed accurate and immediate assessment of the need for a bypass.
Five of these equivocal lesions did not produce any alterations in coronary
reserve and, accordingly, the vessels were not bypassed. In seven of them,
the reactive hyperemia response was markedly depressed and as a result the
vessel in question was bypassed. Thus measurements of coronary reactive
hyperemia in vessels with obstruction of intermediate severity can
influence the operative plan by assessing the physiological significance of
the obstruction.
