Morphology and position of the right atrioventricular valve in relation
to right atrial structures.
Introduction: The aim of this study was to describe the morphology of
the right atrioventricular valve (RAV) and determine its spatial
position in relation to selected structures of the right atrium. Methods
and Results: We examined 200 randomly selected human adult hearts. All
leaflets and commissures were identified and measured. The position of
the RAV was defined. 3-leaflet configurations were present in 67.0% of
cases whereas 4-leaflet configurations were present in 33.0%. Valves
with four leaflets have significantly larger perimeter (119.2±11.1 vs.
109.3±11.3mm, p=0.001). No significant difference was found in superior
leaflet length and height between 3- and 4-leaflet RAVs. Septal and
mural leaflets were both significantly shorter and higher in 4-leaflet
than in 3-leaflet RAVs. Significant domination of the muro-septal
commissure in 3-leflet valves was noted. The supero-septal commissure
was the most stable point within RAV circumference, with no difference
in its position between 3- and 4-leaflet valves. In 3-leaflet valves the
muro-septal commissure was placed within cavo-tricuspid isthmus area in
52.2% of cases, followed by the right atrial appendage vestibule region
(20.9%). In 4-leaflet RAVs, the infero-septal commissure was located
predominantly in the cavo-tricuspid isthmus area and infero-mural
commissure was always located within the right atrial appendage
vestibule region. Conclusions: The RAV is a highly variable structure.
The supero-septal part of the RAV is the least variable component,
whereas the infero-mural is the most variable. The number of detected
RAV leaflets significantly influences the relative position of
individual valve components in relation to right atrial structures.