What is the pathophysiology of decreased output in cor pulmonale?

Updated: Dec 15, 2017
  • Author: Derek Leong, MD; Chief Editor: Henry H Ooi, MD, MRCPI  more...
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Answer

Answer

The RV is a thin-walled chamber that is a better volume pump than a pressure pump. It is better suited to adapt to changing preload than afterload. With an increase in afterload, the RV systolic pressure is increased to maintain the circulatory gradient. At a critical point, a further increase in pulmonary arterial pressure and resistance produces significant RV dilatation, an increase in RV end-diastolic pressure, and RV circulatory failure.

A decrease in RV output leads to a decrease in LV filling, which results in decreased cardiac output. Because the right coronary artery originates from the aorta, decreased LV output causes decreased right coronary blood flow and ischemia to the RV wall. What ensues is a vicious cycle between decreases in LV and RV output.


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