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TESTS and IMAGING
Echocardiography Æ most
tech. Evaluate whether effusion led to
tamponade… important indicator of high pressure fluid is compression of RV and RA during diastole (good pic of what echo image will look like on pg 56 – fig 3.12)… echo can
differentiate b/t tamponade and other causes of low CO
Cardiac catheterization Æ definitive diagnostic procedure. Measures intracardiac and intrapericardial pressures… (below is a measure of RA pressures)
In early diastole (the dotted line), normally, the tricuspid opens and there is a rapid decline (the y descent) in RA pressure as blood flows into the RV… in cardiac tamponade, the pericardial fluid is pushing on the RV during diastole, so it can’t fill as easily, so the RA can’t empty as quickly, and thus, the y descent is blunted in cardiac tamponade.
Can also do a pericardiocentises along with the catheterization…and after pericardiocentises, you’ll want to keep some pericardial fluid for diagnostic purposes Æ stain for bacteria, fungi… get cell counts… protein levels… adenosine deaminase levels (high levels are sens and spec for TB)
Pericardiocentises is the only intervention that can save the patient’s life.