CARDIOVASCULAR FLASHLIGHT
Magnetic resonance assessment of fibrosis in systemic right ventricle after atrial switch procedure
Magalie Ladouceur1,2*, Patrick Bruneval2-4, and Elie Mousseaux2-6
1Congenital Adult Heart Disease Unit, Hôpital Européen Georges Pompidou, 20-21 rue Leblanc, Paris 75015, France; 2Paris Descartes University, France; 3Department of Pathology, Hôpital Européen Georges Pompidou, 20-21 rue Leblanc, Paris 75015, France; 4Unité Inserm 970, Centre de Recherche Cardiovasculaire à l'HEGP, Paris, France; 5Department of Cardiovascular Radiology, Hôpital Européen Georges Pompidou, 20-21 rue Leblanc, Paris 75015, France; and 6Unité Inserm 678, Laboratoire d'Imagerie Fonctionnelle, Paris, France* Corresponding author. Tel: +33 156 095 086, Fax: +33 156 092 664, Email: magalie.ladouceur@egp.aphp.fr
A 27-year-old patient with transposition of great vessels operated by atrial switch procedure, in the neonatal period (Senning intervention), received a heart transplant because of a severe systemic right ventricle failure. Cardiovascular magnetic resonance was performed 3 months before the transplantation and results were compared with macroscopic and histological analysis of the explanted heart.
Cardiovascular magnetic resonance revealed a severe systemic right ventricular (RV) dilatation and hypokinesia (Panel A1). Two-dimensional myocardial delayed enhancement sequences disclosed late gadolinium enhancement (LGE) area in RV inferior wall and septum, in short-axis view (Panel A2, white arrows). All areas of LGE along the RV free wall and septum were corresponding to large areas of fibrosis at macroscopic and histological analysis with focally increased collagen content (Panel B, white arrows). The red Sirius staining showed many large foci of dense and contiguous fibrosis, like in the inferior wall (Panel C1, black arrow), where mean fibrosis density was measured at 25%. Diffuse interstitial fibrosis associated with small foci of fibrosis was also found in all layers of myocardium at many sites and was not detected by late gadolinium. This is the case in RV anterior wall where the red Sirius staining revealed areas of light interstitial fibrosis [Panel C2, black arrows—note light pericoronary fibrosis around the coronary branch (Vx)], where mean fibrosis density was 5%. Fibrosis was only detected by LGE when it was dense and large area regarding to the size of the pixel (Panels C1 and C2, black bar = 1.5 mm, close to 1.44 mm MR pixel size).
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