Right-->left blood shunt

[Jane2005]

Does any know the pathophys involved R--> L blood shunt caused by pulmonary edema, pneumonia, and chronic liver disease ? These are listed as the possible causes of the shunt in a high yield book. Thanks

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[trudub]

Those would most likely be causes of reversing an L to R shunt to a R to L shunt. These conditions cause the pressure in the right side of the heart to increase and thus as right sided pressures exceed left sided pressures you reverse the shunt. As direct causes of an R to L shunt, I don't think those conditions you listed are direct causes.

 

[joe6102]

Does any know the pathophys involved R--> L blood shunt caused by pulmonary edema, pneumonia, and chronic liver disease ? These are listed as the possible causes of the shunt in a high yield book. Thanks

In those two lung diseases, some alveoli are not ventilated, so blood flows from the right heart to the left heart without gas exchange, a physiological shunt (as opposed to anatomical shut such as ASD/VSD).
In chronic liver disease, I'm not sure, but I think it has to do with high pressure in the portal system causes anastomoses, like caput medusa and esophageal varices. Not sure how that is a shunt though, because it should all end up in the right heart eventually.

 

[SeventhSon]

In those two lung diseases, some alveoli are not ventilated, so blood flows from the right heart to the left heart without gas exchange, a physiological shunt (as opposed to anatomical shut such as ASD/VSD).
In chronic liver disease, I'm not sure, but I think it has to do with high pressure in the portal system causes anastomoses, like caput medusa and esophageal varices. Not sure how that is a shunt though, because it should all end up in the right heart eventually.

by very poorly understood mechanisms, chronic liver disease patients may also have anastamoses at the level of the pulmonary artery --> vein, making an anatomic RL shunt (assumedly mediated by a growth factor that circulates in the blood in response to the disturbances in the liver)

 

[goodies]

do you guys know what a left parasternal heave is? it is a sign of right ventricular hypertrophy, but i don't know what the heck "parasternal HEAVE" is... and why left instead of right?

 

[winsicle]

do you guys know what a left parasternal heave is? it is a sign of right ventricular hypertrophy, but i don't know what the heck "parasternal HEAVE" is... and why left instead of right?

L parasternal = area that borders Left-side of sternum (i.e., around where the heart is located)

Heave = while placing your hand over the area, the hand is actually lifted up off the chest due to an abnormally strong impulse from the heart (indicating RVH)

 

[Thievery Corp.]

It's known as parasternal lift too. But "Heave" sounds so much more impressive.

 

[goodies]

L parasternal = area that borders Left-side of sternum (i.e., around where the heart is located)

Heave = while placing your hand over the area, the hand is actually lifted up off the chest due to an abnormally strong impulse from the heart (indicating RVH)

wow, that's interesting. didn't know that. thanks!!


is accentuated p2 with pulm HTN the same thing as wide splitting with pulmonic stenosis?