RVF in PE

Q: What is the mechanism of Right Ventricular Failure (RVF) in Pulmonary Embolism (PE)?

Answer: The objective of this question is to underline the fact that understanding the pathophysiology of any systemic disease goes a long way in clinicians' management of disease down the line. 

RVF occurs in PE via stepwise systemic failure. It largely depends on the clot burden and the physical obstruction of the vascular bed. This leads to hypoxia and subsequently vasoconstriction within the pulmonary arterial system, called hypoxic response. Increased vasoconstriction increases pulmonary vascular resistance (PVR). Increased PVR impedes right ventricular outflow., which progressively leads to right ventricular dilation, and flattening or bowing of the intraventricular septum. RV dilatation and decreased flow from RV eventually lead to cardiogenic collapse.

In conclusion, pulmonary hypoxic vasoconstriction plays an integral role in RV failure due to PE.

#cardiology

#pulmonary

References:

1. Bryce YC, Perez-Johnston R, Bryce EB, Homayoon B, Santos-Martin EG. Pathophysiology of right ventricular failure in acute pulmonary embolism and chronic thromboembolic pulmonary hypertension: a pictorial essay for the interventional radiologist. Insights Imaging. 2019 Feb 13;10(1):18. doi: 10.1186/s13244-019-0695-9. PMID: 30758687; PMCID: PMC6375098.

2. Arrigo M, Huber LC, Winnik S, Mikulicic F, Guidetti F, Frank M, Flammer AJ, Ruschitzka F. Right Ventricular Failure: Pathophysiology, Diagnosis and Treatment. Card Fail Rev. 2019 Nov 4;5(3):140-146. doi: 10.15420/cfr.2019.15.2. PMID: 31768270; PMCID: PMC6848943.