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Updated: Aug 11, 2026
Myocardial Infarction and Functional Outcome Assessment in Pigs
Published on: April 25, 2014
Ability of the no-reflow phenomenon during an acute myocardial infarction to predict left ventricular dysfunction at
M D Kenner1, E J Zajac, G T Kondos
1University of Illinois at Chicago 60612, USA.
Insights
The no-reflow phenomenon, a failure of tissue perfusion after opening blocked arteries in acute myocardial infarction (AMI), affects up to 29% of patients. Myocardial contrast echocardiography can identify this, and early perfusion patterns predict heart function recovery.
Area of Science:
- Cardiology
- Echocardiography
- Myocardial Infarction
Background:
- Some patients with acute myocardial infarction (AMI) do not recover left ventricular function despite successful arterial opening.
- The "no-reflow" phenomenon, characterized by impaired tissue perfusion, is implicated in this functional deficit.
- Assessing microvascular reperfusion is crucial for understanding post-AMI outcomes.
Purpose of the Study:
- To evaluate the utility of myocardial contrast echocardiography (MCE) in identifying the no-reflow phenomenon.
- To correlate immediate post-intervention perfusion patterns with 1-month left ventricular function in AMI patients.
- To determine the incidence of no-reflow in patients undergoing primary percutaneous coronary intervention.
Main Methods:
- Myocardial contrast echocardiography (MCE) was performed before and after infarct-related artery opening in 24 AMI patients.
- Coronary angiograms, regional wall motion, and MCE-derived myocardial contrast enhancement were assessed.
- Follow-up MCE and wall motion analysis were conducted at 1 month in 12 patients.
Main Results:
- The no-reflow phenomenon was identified in 29% of AMI patients (7 out of 24).
- Post-intervention, 15% of myocardial regions exhibited no-reflow, 41% partial reflow, and 44% normal flow.
- At 1 month, normally perfused segments regained function, while hypokinesis/akinesis was observed in segments with initial partial or no-reflow.
Conclusions:
- Myocardial contrast echocardiography effectively identifies the no-reflow phenomenon in acute myocardial infarction.
- The degree of immediate myocardial perfusion after intervention predicts left ventricular functional recovery at 1 month.
- MCE provides valuable insights into microvascular dysfunction and its impact on cardiac outcomes post-AMI.
Abstract:
Despite angiographically successful opening of an infarct-related vessel within a 6-hour time frame, some patients do not recover left ventricular regional wall function in the infarct zone after an acute myocardial infarction (AMI). Recent evidence suggests that this finding is due to the no-reflow phenomenon, or failure to recover tissue perfusion despite patient epicardial arteries. We performed myocardial contrast echocardiography to assess tissue perfusion before and after opening of an infarct-related artery. Coronary angiograms, regional wall motion scoring, and myocardial contrast enhancement were graded by 3 observers. Of 24 patients with AMI, 7 (29%) failed to recover tissue perfusion in > or = 1 region of myocardium. Of 106 regions subtended by the infarct-related artery, 16 (15%), 43 (41%), and 47 (44%) regions had no-reflow, partial, or normal flow, respectively, after arterial patency was established. There was a spectrum of reperfusion patterns ranging from no-reflow to normal perfusion. One-month follow-up angiographic and myocardial contrast echocardiographic studies were performed in 12 of the 24 patients. At 1 month, all segments of myocardium that had immediate normal perfusion had regained normal wall motion. In contrast, 17 segments that had partial or no-reflow were identified. Of these 17, 3 regained normal function, 10 segments were hypokinetic, and 4 segments were akinetic. We conclude that myocardial contrast echocardiography can be used to identify the no-reflow phenomenon in up to 29% of patients with AMI. Additionally, we found that the immediate-reflow pattern can predict degree of left ventricular dysfunction at 1-month follow-up.
