However, the murmur may be inaudible due to the  relatively low pressures in the right side of the heart. A third heart sound may also be present, also heard at the lower sternal border, and increasing in intensity with inspiration.On examination of the neck, there may be giant C-V waves in the jugular pulse. With severe TR, there may be an enlarged liver detected on palpation of the right upper quadrant of the abdomen; the liver may be pulsatile on palpation and even on inspection. Causes
The causes of TR may be classified as  congenital or acquired; another classification divides the causes into primary or secondary. Congenital abnormalities are much less common than acquired. The most common acquired TR is due to right ventricular dilatation. Such dilatation is most often due left heart failure or pulmonary hypertension. Other causes of right ventricular dilatation include right ventricular infarction, inferior myocardial infarction, and cor pulmonale.In regards to primary and secondary causes they are:

Mechanism
In terms of the mechanism of tricuspid insufficiency, it involves the expansion of the tricuspid annulus (fibrous rings of heart). Tricuspid insufficiency is linked to geometric changes of the tricuspid annulus (decreased tricuspid annular release). The leaflets shape are normal but prevented from normal working mechanism due to a distortion of spatial relationships of leaflets and chords. It is also contemplated that the process via which tricuspid regurgitation emerges, is a decrease of contraction of the myocardium around the annulus. Diagnosis
The diagnosis of TR may be suspected if the typical murmur of TR is heard.
Athletes with tricuspid regurgitation also had enlarged right atrium diameter when compared to control group. See also
Heart valves

References
Sources
Mestres, Carlos A.; Bernal, Jose M.; Pomar, Jose L. (2016). "Surgical Treatment of Tricuspid Valve Diseases". In Frank Sellke; Pedro J. del Nido (eds.). Sabiston and Spencer Surgery of the Chest. ISBN 978-0-323-24126-7. Further reading
Haddad, F; Doyle, R; Murphy, D. J; Hunt, S. A (2008). "Right Ventricular Function in Cardiovascular Disease, Part II: Pathophysiology, Clinical Importance, and Management of Right Ventricular Failure". Circulation. 117 (13): 1717–1731. doi:10.1161/CIRCULATIONAHA.107.653584. PMID 18378625. Desai, Ravi R; Vargas Abello, Lina Maria; Klein, Allan L; Marwick, Thomas H; Krasuski, Richard A; Ye, Ying; Nowicki, Edward R; Rajeswaran, Jeevanantham; Blackstone, Eugene H; Pettersson, Gösta B (2013). "Tricuspid regurgitation and right ventricular function after mitral valve surgery with or without concomitant tricuspid valve procedure". The Journal of Thoracic and Cardiovascular Surgery. 146 (5): 1126–1132.e10. doi:10.1016/j.jtcvs.2012.08.061. PMC 4215162. PMID 23010580. Badano, Luigi P; Muraru, Denisa; Enriquez-Sarano, Maurice (2013). "Assessment of functional tricuspid regurgitation". European Heart Journal. 34 (25): 1875–1885. doi:10.1093/eurheartj/ehs474. PMID 23303656. al. ], Hugh D. Allen ... [et; Shaddy, Robert E.; Feltes, Timothy F. (2013). Moss and Adams heart disease in infants, children, and adolescents : including the fetus and young adult (8th ed.). Philadelphia: Wolters Kluwer Health/Lippincott Williams & Wilkins. ISBN 9781451118933. == External links ==