Cardiac involvement in dermatomyositis (DM) is infrequent but is associated with poor prognosis1. Myocardial fibrosis has been observed in histopathological studies of DM and has been attributed to myocardial inflammation2. Reports describing its noninvasive in vivo visualization in DM are lacking. Fibrosis represents a common substrate of ventricular arrhythmias in an array of non-ischemic cardiomyopathies and possibly in DM as well3.
A 58-year-old woman with DM first diagnosed 6 years earlier was referred for cardiovascular magnetic resonance imaging (MRI) because of progressive exertional dyspnea. Examination revealed bilateral atrial enlargement, which was much more pronounced in the right atrium (steady-state free precession). In addition, an area of myocardial late enhancement (inversion-recovery gradient echo) was noted in the basal posterolateral wall, together with a small pericardial effusion (Figure 1). There was no evidence of myocardial edema (T2-weighted image) or hyperemia (early contrast-enhancement), considering the skeletal muscle as an internal reference. Coronary angiography revealed no significant coronary artery stenosis, indicating that the fibrosis was non-ischemic.
Myocardial late enhancement was noted in the basal posterolateral wall (A: circle), together with a small pericardial effusion (B: arrows). RA: right atrium; RV: right ventricle; LA: left atrium; LV: left ventricle.
The unique ability of cardiovascular MRI to visualize focal myocardial fibrosis noninvasively in this setting may offer a novel method of risk stratification.
