We sought to understand how leaflet forces change in response to annular dilation and leaflet tethering in single ventricle physiology. Explanted fetal bovine tricuspid valves were sutured onto image-derived annuli and ventricular mounts. Control valves (CV) were secured to a size-matched HLHS-type annulus and compared to: 1) normal tricuspid valves (NTV) secured to a size-matched saddle-shaped annulus, 2) HLHS-type annulus with leaflet tethering (LT), 3) HLHS-type annulus with annular dilation (DIL), or 5) a combined disease model with both dilation and tethering (DIS). The specimens were tested in a systemic heart simulator at various SVPs. Leaflet forces were measured using optical strain sensors sutured to each leaflet edge. Average force in the anterior leaflet was 43.2% lower in CV compared to NTV (p<0.001). LT resulted in a 6.6% increase in average forces on the anterior leaflet (p=0.04), 10.7% increase on the posterior leaflet (p=0.03), and 14.1% increase on the septal leaflet (p<0.001). In DIL, average septal leaflet forces increased relative to the control valves by 42.2% (p=0.01). In DIS, average leaflet forces increased by 54.8% in the anterior leaflet (p<0.001), 37.6% in the posterior leaflet (p=0.03), and 79.9% in the septal leaflet (p<0.001). The anterior leaflet experiences the highest forces in the normal tricuspid annulus under SVP conditions. Annular dilation resulted in an increase in forces on the septal leaflet and leaflet tethering resulted in an increase in forces across all 3 leaflets. Annular dilation and leaflet tethering combined resulted in the largest increase in leaflet forces across all 3 leaflets.
View details for DOI 10.1053/j.semtcvs.2022.09.012
View details for PubMedID 36455710