Thursday, September 17, 2015

JVP in pericardial tamponade

Greetings everyone!

Today, I was reading about JVP in pericardial tamponade. I started explaining a few concepts to myself and then I thought maybe everyone would like to know about this! So I wrote them down for you guys to read.

Why is y descent absent in JVP in pericardial tamponade? 
Y wave is due to ventricular relaxation. The ventricles can't relax when the pericardium is full of fluid, leading to the absence of y descent.

JVP in pericardial tamponade
Why is there a prominent x descent in JVP of pericardial tamponade?

(This is plain awesome to understand. I'm going to explain it in my own words.)
During systole, the pericardial pressure becomes a little negative (In very lay man terms, ventricle contracts so space in the pericardium increases) which momentarily relieves the tamponade.
This negative wave is transmitted to the atria which causes an exaggerated atrial relaxation, pulling all the blood inside the atrium, leading to a prominent x descent.

A more complex explanation, copied from blaufuss (http://www.blaufuss.org/HSM/TEXT/TAMP_CPC_txt.html) for reference.

Pericardial Tamponade
The atrial pulse contour in tamponade is unique. The elevated pressure exhibits a prominent x-descent while lacking a diastolic y-descent or developing a y-ascent. These changes can also be appreciated in the jugular venous pulse.
With tamponade, the pericardial space is hydraulically distended under sufficient tension to raise filling pressures equally in all chambers and impair diastolic filling. Under these conditions a pericardial systolic negative wave results from the ejection of blood by the ventricles which momentary relieves the tamponade. This negative wave is transmitted to the atria as an exaggerated x-descent that draws in a surge of venous blood. The systolic reduction in intra-pericardial space makes room for venous blood.

The venous input matches the ventricular output by the end of systole, and the intra-pericardial space is once again full. When diastolic ventricular relaxation ensues, loss of blood from the atria does not relieve atrial pressure because the hydraulic action of the displaced pericardial fluid now impinges on the emptying atria. Right atrial communication with the engorged systemic venous reservoir also tends to maintain a high level of pressure in the atria, preventing the y-descent and often producing a y-ascent.

That's all!
There's a fine line between coincidence and fate.
-IkaN

2 comments:

This is express yourself space. Where you type create something beautiful! <3
Wondering what do I write? Well..
Tell us something you know better. You are a brilliant mind. Yes, you are! ^__^
Ask about something you don't understand @_@?
Compliment... Say something nice! =D
Be a good critic and correct us if something went wrong :|
Go ahead. Comment all you like here! (:

Related Posts Plugin for WordPress, Blogger...