Visualization of Endomyocardial Fibrosis by Delayed-Enhancement Magnetic Resonance Imaging
An 18-year-old Venezuelan woman, with a history of idiopathic restrictive cardiomyopathy, presented at our hospital with ongoing dyspnea, palpitations, and lightheadedness. A medical evaluation revealed heart failure, pulmonary hypertension, and heparin-induced thrombocytopenia.
Cardiac catheterization revealed normal coronary arteries. The left ventriculogram demonstrated late filling of the apex, which was almost obliterated by prominent trabeculations. Moderate mitral regurgitation with significant enlargement of the left atrium was observed. The ejection fraction was 44%, without regional wall motion abnormalities (Figure 1).
Cine MRI (steady-state free-precession technique) demonstrated systemic venous dilatation, moderate pericardial effusion, right and left atrial dilatation, and mitral and tricuspid regurgitation (TR) (Figures 2 and 3⇓, Movies I and II). The origin of the TR jet was dislocated toward the apex of the right ventricle, originating within the right ventricular cavity, possibly secondary to papillary muscle fibrosis (Figure 2, Movie I). Delayed-enhancement MRI image was acquired via an inversion recovery technique after injection of 0.2 mmol/kg of gadolinium (Gd-DTPA). The MRI revealed subendocardial hyperenhancement of the apex of the left ventricle, suggesting fibrosis (Figure 4). This technique has been used to detect irreversible myocardial injury (fibrosis or necrosis).
A myocardial biopsy of the right ventricle confirmed the presence of endomyocardial fibrosis. The patient underwent endomyocardial stripping, mitral valve replacement, and tricuspid ring valvuloplasty. Postoperatively, the patient developed refractive congestive heart failure, which progressed to cardiogenic shock and death. Histological examination of the heart revealed endomyocardial fibrosis, involving particularly the ventricles and left atrium (Figures 5 and 6⇓).
Delayed-enhancement MRI technique allows the detection of subendocardial fibrosis with good histopathological correlation, providing a comprehensive tool for noninvasive assessment of endomyocardial fibrosis.
The online-only Data Supplement, which contains Movies I and II, is available with this article at http://www.circulationaha.org.