motorola
how.do.u.spell.H1b?
Topics: 63
Posts: 366
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When Left atrial pressure rises the pressure in pulonary veins will rise. Hence pressure in the pulmonary capillaries will rise and this is measured in by the PCWP catheter.
PCWP is measured only because it is not possible to enter the LA directly. Imagine to enter LA one would have to puncture the femoral artery->aorta->LV->mitral valve->LA. This is dangerous.
Instead of this the route followed by PCWP catheter is this. Femoral vein -> IVC -> RA -> RV -> PA -> Pulmonary capillary.
It is like measuring LA pressure from the other end !
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| docdocdoc
Forum Newbie
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Posts: 6
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well i think during diastole atrial pressure and left ventricular pressure are almost same (there is a small difference however) therefore measuring left atrial pressure will give us left ventricular end diastolic pressure.
PCWP will not accurately depict preload as for example in mitral valve disease.
therefore PCWP is not a accurate indice of preload.
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| docdocdoc
Forum Newbie
Topics: 3
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Please comment on this topic as i wanna make this concept clear
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| onyx
Forum Newbie
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You are right, during diastole the opened mitral valve offers minimal resistance to blood flow making left atrial and ventricular pressures almost the same.
so measuring left atrial pressure give an estimate of preload ( LV EDP).
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| mjbapana
Forum Senior
Topics: 26
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PCWP is not an exact measure but it is used only clinically to get a as close to as possible value for preload and u r right it is not an exact measure.the further away u r from the ventricle the less reliable the the index is what kaplan says but still used clinically.more accurate would be LV EDV and LV EDP
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