OBJECTIVES: Differentiation between primary dilated cardiomyopathy and ischemic 
cardiomyopathy has an important clinical significance. Contrast-enhanced 
cardiovascular magnetic resonance can play a role in this task, identifying 
myocardial scarring or fibrosis as presence of delayed enhancement. The aim of 
the present study was to evaluate the diagnostic potential of contrast-enhanced 
cardiovascular magnetic resonance in differentiating dilated cardiomyopathy from 
ischemic cardiomyopathy.
METHODS: Contrast-enhanced cardiovascular magnetic resonance was performed in 
100 patients with left ventricular dilatation and reduced systolic function: 24 
had normal coronary arteries (dilated cardiomyopathy group) and 76 had 
significant coronary artery disease (ischemic cardiomyopathy group), with or 
without previous myocardial infarction.
RESULTS: In the dilated cardiomyopathy group, only seven (29%) patients showed 
delayed enhancement and its pattern was characterized by mid-wall, patchy or 
diffuse location. All patients with ischemic cardiomyopathy and prior myocardial 
infarction (54 subjects) showed delayed enhancement with subendocardial (n = 4) 
or transmural (n = 50) extension. Among the 22 patients with ischemic 
cardiomyopathy but without previous myocardial infarction, 13 (59%) showed 
either subendocardial (n = 4) or transmural (n = 9) delayed enhancement.
CONCLUSIONS: Patterns of delayed enhancement are different in dilated 
cardiomyopathy and ischemic cardiomyopathy, reflecting the presence of scarring 
or various degrees of fibrosis in left ventricular myocardium. The presence of 
subendocardial or transmural delayed enhancement at contrast-enhanced 
cardiovascular magnetic resonance allowed distinction between dilated 
cardiomyopathy and ischemic cardiomyopathy with high sensitivity (88%) and 
specificity (100%). Integration of cardiovascular magnetic resonance results 
with angiographic information can be useful in the identification of pathogenic 
mechanisms underlying left ventricular dysfunction.