Author + information
- ↵∗Address for correspondence: Sanjiv Kaul, MD, Division of Cardiology, Box 158, University of Virginia, Charlottesville, Virginia 22908.
Coronary vasodilators increase coronary flow by increasing myocardial blood volume. Diseases affecting the coronary microvasculature will affect vasodilator-induced changes in coronary flow by inhibiting changes in myocardial blood volume. In such cases, when myocardial time-intensity curves after administration of a vasodilator are compared with those at baseline, a less than anticipated increase in microbubble transit rates will be noted. As long as we understand what we are measuring in the context of where and how we inject the bubbles, we can begin to define the role of myocardial contrast echocardiography in assessing changes in coronary microvascular reserve. It is also conceivable that because myocardial contrast echocardiography can assess changes in myocardial flow/volume relations rather than just changes in flow, this technique could be used to provide additional insights into the mechanisms of action of different coronary vasodilators and into the pathophysiology of various diseases affecting the coronary microvasculature. Finally, with the advent of commercially available microbubbles, robust on- and off-line analysis algorithms and intracardiac imaging, myocardial contrast echocardiography may become an invaluable adjunct to coronary angiography for determining the pathophysiologic significance of coronary disease in individual patients.
↵1 Dr. Kaul is an Established Investigator of the American Heart Association.
☆ Editorials published in Journal of the American College of Cardiologyreflect the views of the authors and do not necessarily represent the views of JACC or the American College of Cardiology.
☆☆ This work was supported in part by Grant R01-HL48890 from the National Institutes of Health, Bethesda, Maryland and grants-in-aid from the Virginia Affiliate of the American Heart Association, Glen Allen, Virginia and the National Center of the American Heart Association, Dallas, Texas.