ABSTRACT
BACKGROUND: Dilated cardiomyopathy (DCM) is often associated with progressive heart failure or ventricular arrhythmia. Look-Locker magnetic resonance imaging (MRI) allows quantitative evaluation of interstitial fibrosis by measuring the myocardial T1 value, and delayed enhancement (DE) MRI visualizes myocardial scar. PURPOSE: To determine the relationship of postcontrast myocardial T1 value or DE to reduced cardiac function or sustained ventricular tachycardia (SVT) in DCM patients with a left ventricular ejection fraction (LVEF) <35%. MATERIAL AND METHODS: We enrolled 41 patients with DCM. Correlations between the cardiac function parameters and postcontrast myocardial T1 value or extent of DE were evaluated. The relationship between SVT and the T1 values or extent of DE was assessed. The correlation between the extent of DE and the T1 value was also examined. RESULTS: The postcontrast myocardial T1 value was significantly correlated with the LVEF (P < 0.05; r = 0.31) and end-diastolic volume (P < 0.01; r = -0.40) in 40 patients with LVEF <35%. DE was not correlated with the cardiac function, but provided a high negative predictive value of 94.7% for SVT. No correlation was found between the myocardial T1 value and extent of DE. CONCLUSION: In DCM patients with LVEF <35%, the postcontrast myocardial T1 value correlated with the severity of cardiac dysfunction, and the absence of DE indicated the low risk of SVT. Both MRI parameters should be estimated because they may reflect discrete forms of myocardial damages in patients with DCM.
