Rapid initial reduction of hyperenhanced myocardium after reperfused first myocardial infarction suggests recovery of the peri-infarction zone: one-year follow-up by MRI.

Published

Journal Article

The time course and magnitude of infarct involution, functional recovery, and normalization of infarct-related electrocardiographic (ECG) changes after acute myocardial infarction (MI) are not completely known in humans. We sought to explore these processes early after MI and during infarct-healing using cardiac MRI.Twenty-two patients with reperfused first-time MI were examined by MRI and ECG at 1, 7, 42, 182, and 365 days after infarction. Global left ventricular function and regional wall thickening were assessed by cine MRI, and injured myocardium was depicted by delayed contrast-enhanced MRI. Infarct size by ECG was estimated by QRS scoring. The reduction of hyperenhanced myocardium occurred predominantly during the first week after infarction (64% of the 1-year reduction). Furthermore, during the first week the amount of nonhyperenhanced myocardium increased significantly (P<0.001), although the left ventricular mass remained unchanged. Left ventricular ejection fraction increased gradually, whereas the greater the regional transmural extent of hyperenhancement at day 1, the later the recovery of regional wall thickening. Regional wall thickening decreased progressively with increasing initial transmural extent of hyperenhancement (P(trend)<0.0001). The time course and magnitude of decrease in QRS score corresponded with the reduction of hyperenhanced myocardium.The early reduction of hyperenhanced myocardium may reflect recovery of hyperenhanced, reversibly injured myocardium, which must be considered when predicting functional recovery from delayed contrast-enhanced MRI findings early after infarction. Also, the time course and magnitude for reduction of hyperenhanced myocardium were associated with normalization of infarct-related ECG changes.

Full Text

Cited Authors

  • Engblom, H; Hedström, E; Heiberg, E; Wagner, GS; Pahlm, O; Arheden, H

Published Date

  • January 2009

Published In

Volume / Issue

  • 2 / 1

Start / End Page

  • 47 - 55

PubMed ID

  • 19808564

Pubmed Central ID

  • 19808564

Electronic International Standard Serial Number (EISSN)

  • 1942-0080

International Standard Serial Number (ISSN)

  • 1941-9651

Digital Object Identifier (DOI)

  • 10.1161/circimaging.108.802199

Language

  • eng