Abstract
Background
The actual role of the coronary microcirculation, which is massively injured by myocardial infarction (MI), in intramyocardial hemorrhage (IMH) pathophysiology is still not fully understood.
Purpose
To determine the change and distribution of microcirculation of myocardial edema (ME), IMH, MI, and the remote area of early reperfusion using 7.0-T cardiovascular magnetic resonance (CMR) in a rat model of acute MI.
Material and Methods
Eight rats with 60-min myocardial ischemia followed by reperfusion were investigated. On days 2 and 7, after the acquisition of T2*-mapping and T2-mapping images, late gadolinium enhancement imaging was performed to evaluate the extent of myocardial ischemia after an injection of Gd-DTPA. On days 3 and 8, after the injection of ultrasmall superparamagnetic iron oxide (USPIO), T2*- and T2-mapping images were acquired. The R2 values of ME, IMH, MI, and remote areas were measured.
Results
From days 2 to 3, R2 values increased in the IMH, MI, ME, and remote area (all P < 0.05) following administration of USPIO, while the delta R2 value of IMH and MI was larger than remote area (P < 0.05). From day 7 to day 8, there was no significant difference in the IMH, MI, ME, and remote area (all P > 0.05).
Conclusion
Microvascular injury of IMH and MI is the most severe among all the studied myocardial injuries in the early reperfusion of MI, while microvascular density decreased during follow-up.
Keywords
Get full access to this article
View all access options for this article.