The most common cause of tricuspid regurgitation is secondary to
Ref Harrison 19 th ed pg 1548 In at least 80% of cases, TR is secondary to marked dilation of the tricuspid annulus from RV enlargement due to PA hypeension .Functional TR may complicate RV enlargement of any cause, however, including an inferior myocardial infarction (MI) that involves the RV.
Rheumatoid hea disease
Dilation of right ventricle
Coronary aery disease
Endocarditis due to intravenous drug abuse
General anatomy