Quantification of elastin for annular (A) belly (B) and free edge (C) regions of tricuspid leaflets stained with Movat’s pentachrome. Representative annular region images of CTL (D) and FTR (E) leaflets demonstrating increases in elastin content. Belly region of tricuspid leaflets for CTL (F) and FTR (G) demonstrate significant decreases in collagen and concomitant increases in GAGs for annular (H, K) belly (I, L) and free edge (J, M) regions of tricuspid leaflets. ATL: anterior tricuspid leaflet; CTL: control; FTR: functional tricuspid regurgitation; GAGs: glycosaminoglycans; PTL: posterior tricuspid leaflet; STL: septal tricuspid leaflet. *P < 0.05).