The use of myocardial contrast echocardiography in clinical evaluation after myocardial infarction.
Because disruption of the microvasculature is a hallmark of myocyte necrosis, MCE may be able to distinguish between viable and infarcted tissue. In order to interpret images appropriately following myocardial infarction, however, one should be versed in the pathophysiology of post-ischemic reflow, and understand that reperfusion to infarcted tissue is a heterogeneous combination of hyperemia, low-reflow, no-reflow, and impaired microvascular flow reserve. Furthermore, the relative mix of these perfusion patterns changes both temporally and spatially, which has implications for the timing of MCE following reperfusion. The identification of no- and low-reflow by MCE predicts regions unlikely to demonstrate segmental functional recovery, and is associated with adverse clinical events. To date, studies documenting the utility of MCE in the AMI setting have been performed using intracoronary injections in the cardiac catheterization laboratory. With the advent of intravenous contrast agents and innovations in ultrasound imaging systems, it may be possible to make these determinations without the need for coronary instrumentation, thus expanding the role of MCE in acute infarction and reperfusion to settings such as the emergency room and intensive care unit.
Villanueva
F S
FS
Division of Cardiology, University of Pittsburgh School of Medicine, Pennsylvania, USA. villanuevafs@msx.upmc.edu
D000818:Animals; D003287:Contrast Media; D003326:Coronary Circulation / Q000502:physiology; D004285:Dogs; D004452:Echocardiography / Q000379:methods*; D006801:Humans; D009203:Myocardial Infarction / Q000000981:diagnostic imaging* / Q000503:physiopathology; D015425:Myocardial Reperfusion; D011237:Predictive Value of Tests; D012307:Risk Factors
D003287:Contrast Media