Purpose
The midwall myocardial enhancement seen in dilated cardiomyopathy (DCMP) patients probably reflects fibrosis at autopsy, so we evaluate and analyze the left ventricular (LV) wall motion in patients with nonischemic DCMP related to the presence of delayed myocardial enhancement.
Materials and methods
Thirty-one consecutive patients ( Male : 20 , Female: 11, Mean age: 54.1 years ) with nonischemic DCMP and confirmed unobstructive coronary arteries were enrolled. MRIs with short-axis myocardial tagging and delayed contrast enhancement were performed. With the myocardial tagging images, circumferential myocardial shortening (ECC) and radial myocardial thickening (ERR) were calculated by HARP analysis. The strains of ECC and ERR taken in every segments were analyzed related to myocardial enhancement.
Results
Fourteen patients revealed delayed enhancements of LV myocardium and seventeen patients did not. All patients showed marked regional heterogeneity of LV wall motion and regional paradoxical motion (19/31) by HARP analysis. Reduced wall motion of LV in septum and preserved wall motion in lateral wall were easily detected by HARP analysis. The LV myocardial wall motions by ECC and ERR at each segments were not significantly different in segments with and without delayed myocardial ennhancement ( ECC< mean p-value=0.289>, ERR< mean p-value =0.455>, p<0.05 ) except for anterior wall at the middle and basal LV on ECC, but regional paradoxical motions of LV wall were more seen in patients without delayed myocardial enhancement (12/17 vs 7/14 ).
Conclusion
Short-axis tagged MR imaging and analysis with HARP method showed delicate regional heterogeneity and paradoxical motion in nonischemic DCMP patients, representatively in septum at base. Regional paradoxical motion was more frequently observed in segments without enhancement than with enhancement. Short-axis tagged MRI and HARP analysis can be applied to analyze delicate and complex LV wall motion in nonischemic DCMP patients.
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