Haematoxylin and eosin staining of CTL (A) and FTR (B) septal leaflets demonstrating a trend in increased leaflet size (C). Cellularity (D) was increased in FTR leaflets with representative septal leaflets of CTL (E) and FTR (F) animals. ATL: anterior tricuspid leaflet; CTL: control; FTR: functional tricuspid regurgitation; PTL: posterior tricuspid leaflet; STL: septal tricuspid leaflet. *P < 0.05).