AV valves exist to divert blood to the outflows when ventricles are contracting. If they leak significantly, obviously there are major consequences. What happens to the net cardiac output when these valves leak?
Clincally , we know ,fatigue is sign of reduced forward cardaic out put , that is more common in MR. But, edema , congestion, muscle fatigue is eqaully if not more common with TR. One importnat diference is MR jet is mainly a hemodynamic trouble in pulmonary circuit while TR jet , has one more component hits on liver function making it metabolic consequnce as well.
Can’t escape, tell us your answer for the question
*I am afraid, anyone has done a specific hemodynamic study on this. It should be clear for everyone, that RV stroke volume, is not only the preload of LV, and it is going to bcome LV stroke volume, a few seconds later. Hence TR equally reduce * (if not more ) the forward cardiac output as does MR. In fact, the compensatory mechanism of LV with its reserve work might maintain the forward output for a longer time. RV reserve functions are less.Fellows must analyze this. It is not a difficult one. Measure LV stroke volume by echo ( LVOT area X Aortic TVI) in patients with TR vs MR pre and post-correction.
Final message
RV & LV are like conjoined twins. One’s function can’t be decoupled from the other. Now we realize, TR plays a more central role in both symptom generation and the overall outcome in cardiac failure. Hence, aggressive interventions are being attempted to plug this leak. (We will come to know whether it is truly beneficial or not only later, as arresting TR puts more burden on RV, as TR has a pressure cooker release/relief effect on RV)
Reference
Rebecca T Hahn, Luigi P Badano, Philipp E Bartko, Denisa Muraru, Francesco Maisano, Jose L Zamorano, Erwan Donal, Tricuspid regurgitation: recent advances in understanding pathophysiology, severity grading and outcome, European Heart Journal – Cardiovascular Imaging, Volume 23, Issue 7, July 2022, Pages 913–929, https://doi.org/10.1093/ehjci/jeac009
Dr.S.Venkatesan MD 