Background: Delayed-enhanced MRI (DE-MRI) is a useful modality for detecting fibrotic myocardium.

Methods: We used DE-MRI to detect myocardial fibrosis and studied its distribution and association with arrhythmias. Forty one patients (age 54±11 yrs) with scleroderma (SSc) and no history of ischemic cardiomyopathy were evaluated with ECG, 2 D-echo, and 24-hour Holter study. MRI was obtained with a 1.5T MR scanner. Myocardial fibrosis was assessed by two radiologists and defined as presence of delayed enhancement and absence of edema on T2-weighted images. The distribution of left ventricular hyperenhancement was measured and localized according to the 17-segment myocardial model. DE-MRI was also obtained in 6 healthy volunteers.
Results: Technically acceptable MRIs were obtained in 36 out of the 41 SSc patients and in all control subjects. Myocardial fibrosis was detected in 24 (66.7%) of the patients and in none of the control group. Fibrosis was preferentially distributed in the basal and medial layers of the myocardium following a geometric distribution, being more prevalent in segments 1-6 and limited in segments 13-17 (Figure). Patients with an abnormal Holter study were more likely to have pulmonary hypertension, lower left ventricular EF, larger left atrium, greater number of enhancing segments on DE-MRI, and higher total enhancement volume index (p<0.05 in all). Compared to patients without arrhythmias, a greater portion of patients with arrhythmias had fibrosis in segment 3 (p= 0.017).

Conclusion: DE-MRI can detect myocardial fibrosis in a significant portion of SSc patients. The distribution of fibrosis is mostly basal- and mid-myocardial and may account for the arrhythmias detected in these patients