The right atrium and tricuspid annulus are cardinal structures in tricuspid regurgitation with or without pulmonary hypertension

•It is well known that right heart structural abnormalities occur in tricuspid regurgitation and pulmonary hypertension, and they may occur independently or together. What is unknown is the relative impact of each on cardiac structure.•This study examined the interactions of TR severity and PH on right heart structural changes.•We found that RA Volume and the Tricuspid annulus area were very sensitive to TR severity, but less so to pulmonary hypertension. In significant TR, neither RA volume nor TAA are substantially affected by PH.•RA volume and tricuspid annulus area are thus the most sensitive structures to TR, enlarge in proportion to TR severity. By contrast, pulmonary hypertension impacts RA volume less, and tehn in trace and mild TR.•RA volume best reflects TR impact on right heart structure, both with and without PH. Right atrial volume and tricuspid annulus area are the cardinal indices of TR-induced right heart structural disease et al.l severities.