Author + information
- Received October 30, 1990
- Revision received June 30, 1992
- Accepted July 20, 1992
- Published online February 1, 1993.
- Jayashri R. Aragam, MD,
- Joan Main, BS, RCPT, RCT,
- J.Luis Guerrero, BS,
- Gus J. Vlahakes, MD,
- James F. Southern, MD,
- Mark S. Adams, BS,
- Arthur E. Weyman, MD, FACC and
- Robert A. Levine, MD, FACC∗,1
- ↵∗Address for correspondence: Robert A. Levine, MD, Cardiac Ultrasound Laboratory, Massachusetts General Hospital, Founders House 8, Boston, Massachusetts 02114.
Objectives. We addressed the hypothesis that blood flow could be imaged by Doppler color flow mapping of the coronary arteries and characteristic patterns described in normal and diseased vessels.
Background. Echocardiographic imaging of the epicardial coronary arteries has been suggested as a useful adjunct to their intraoperative evaluation. Addition of Doppler color flow mapping could potentially enhance this evaluation by displaying the flow disturbance produced by anatomic lesions whose physiologic significance may otherwise be uncertain. In experimental models, such displays could also potentially provide insights into the pathophysiology of coronary blood flow and stenosis.
Methods. Epicardial coronary arteries were examined with a high resolution 7-MHz linear phased-array transducer both in vivo and in vitro. 1) The coronary arteries were studied in the beating hearts of 10 open chest dogs in which experimental stenoses were also created; the maximal extent of the arterial tree in which flow could be seen in the most ideal setting was also examined in four additional excised perfused canine hearts. 2) Six excised human coronary arteries were perfused in a pulsatile manner to determine whether abnormal flow patterns could be prospectively identified and subsequently correlated with pathologic evidence of stenosis.
Results. All normal coronary artery segments studied showed homogeneous flow without evidence of flow disturbance. In the excised heart, flow could be visualized to the distal extent of the epicardial vessels; in the open chest model, visualization of the proximal 5 to 6 cm was comparable, although surrounding structures limited access to the terminal portions of the vessels. The stenotic lesions created in the canine hearts (n = 9) showed recognizable alterations in the flow pattern: localized aliasing, proximal blood flow acceleration, distal flow disturbance and recirculatory flow. In the excised human arteries, these features identified 12 lesions, all of which corresponded to areas of ≥50% lumen narrowing by pathologic examination.
Conclusion. Blood flow in the epicardial coronary arteries can be imaged by Doppler color flow mapping and characteristic flow patterns described in normal and diseased vessels.
↵1 Dr. Levine is an Established Investigator of the American Heart Association, Dallas, Texas, with funds contributed in part by its Massachusetts Affiliate, Needham, Massachusetts.
☆ This study was supported in part by Grant HL 38176 from the National Institutes of Health, Bethesda, Maryland and by a grant from the Whitaker Foundation, Camp Hill, Pennsylvania (Dr. Levine).
- Received October 30, 1990.
- Revision received June 30, 1992.
- Accepted July 20, 1992.