Welcome to lecture 13 of our course pericardial effusion. In temporary pericardial effusion is excessive buildup of fluid in the pericardial cavity. a minimal amount of pericardial effusion is a normal finding but an excessive buildup is called pericardial effusion and is a common cardiac disorder with a variety of causes, most frequently viral uremic or autoimmune pericarditis. Another important cause especially in old age is malignancy. pericardial effusion is really visualized by echo in most views and is visible as an echo Lucent cavity around the heart. This is an example of pericardial effusion.
In the pair sternum long access view, we can tell that an effusion is pair cardio by looking at the descending aorta, which marks the end of the parietal pericardium floridly pericardial effusion will light proximal to the descending aorta, while the pleural effusion will lie distal to the descending aorta. This is an example of a patient with both approaches. pericardial effusion This here is the visceral pericardium. This is the parietal pericardium. And this is a pair of cardio fusion in between. This is a pleural effusion.
And you can tell because it's distal to the descending aorta right here. By echocardiography, you can also get an idea about the nature of an effusion. A serious effusion looks clear. hemorrhagic effusion looks bright and speckled. While a fibrous effusion will show layers of organized fibrin proximal to the bridle, pericardium or strands of fiber extending between the bridle and the visceral pericardium This is also an example of what we call a regulated or insisted pericardial effusion in which the fibrin strands divide the pericardial cavity into separate cavities. And and these patients usually needs open pair cardiac to me for drainage case of 10th an ad instead of needle pair cardio and thesis To assess the degree of the pericardial effusion, we use 2d and a view in which the fusion is well visible, and freeze the image in diagonally or the ventricle is most expanded.
Then use the caliper to measure the pericardial effusion. purposes perpendicularly to the Lv diameter less than 0.5 centimeters is minimal and corresponds to an amount of less than 100 milliliters of fluid. Between o point five and one centimeters is moderate and corresponds to an amount between 100 to 500 milliliters of fluid, while above one centimeter is a large effusion corresponding to amounts in excess of 500 milliliters. So what about cardiac cath net cardiac comfort that is when the pericardial fluid causes compression of the on the heart, causing impairment of filling and consequently reduced cardiac output hemodynamic collapse. There isn't a particular amount A fluid that will cause him to nap but it's rather the rate of accumulation of slowly accumulating fusion along weeks can reach up to a couple of liters before causing significant temper net, while a rapidly accumulating effusion can cause temp add with as little as 50 milliliters of fluid because the pericardium has no time to stretch and accommodate the excess fluid.
Diagnosing cardiac tamponade by echo depends on observing pericardial effusion in addition to evidence of chamber compression, or increased ventricular inter-dependence, well, chamber compression is easy. A large template can visibly compress any cardiac chamber making the cavity size small. Particular interdependence needs a bit of explaining though, normally, both ventricles are able to fill and expand freely without crowding each other space on the pericardium starts filling up with fluid however, the heart becomes enclosed in a confined space with a fixed volume. And if one ventricle is to expand, it would be at the expense of the other. This echocardiography manifests itself in several ways The first time we usually observe intention at the earliest sign of temp ad is systolic array collapse, which means collapse of the right atrium in early Sicily well late diagonally and early Sicily. And as we said, this is one of the earliest signs of tampering.
This is another example in which both right and left atrial collapse is very obvious. The second sign is diastolic RV collapse, which is paradoxical collapse of the RV during diastole II, which is because Lv expansion suddenly raises the interpreter cardio pressure, which in turn compresses the thinner and weaker RV. This is short access shot of the same patient and you can very clearly see right ventricular prolapse in this image. Sometimes this change manifests itself in the cases of large effusions as a swinging heart, which is kind of a spot diagnosis for Tampa. Note the location of descending aorta. We now know that this effusion is pericardial and not poor.
The third sign of template is variation of mitral and tricuspid flow with respiration. Let's elaborate on that a little bit. Normally, deep inspiration reduces intrathoracic pressure causes causing a vacuum effect that increases venous return to the right side of the heart. This causes increased flow across the tricuspid valve and the resulting increased RB filling compresses the Lv, and reduces blood flow across the mitral valve. The opposite changes happen with exploration. These changes are normally present to a small degree, but become exaggerated with tempo.
And we assess them using pulse wave Doppler at the mitral and tricuspid valves. This is a trace of a normal transtar cuspid flow. You'll notice that in both these examples, we've increased the sweep speed so that the conflicts Is are closer together and the relationship between them is easy to spot. You can see here how the variation and peak philosophy between the envelopes is obviously less than 30%. Again, you can measure it using the calendar. This is a pulse wave Doppler for tracing from a patient with cardiac tamponade.
You can see that the variation in the peak velocities marked by these dots exceeds 30%. And and this case is in this case it's pretty clear but if if we're now we can use the caliper to measure peak velocity at the highest and lowest envelopes, and and calculate the variation percentage, normally it shouldn't exceed 30%. The final feature we'll discuss is IVC plethora, which simply means a dilated, non compressible IV IVC with respiration in the absence of another cause. If you don't know what that means, you should refer to lecture nine. Finding one No more of these features together with a pericardial effusion is consistent with echocardiography 10th act, and should prompt an examination for clinical signs of temp ads such as hypotension and pulse paradoxes and if indicated, you will pair cardio synthesis. This concludes our lecture.
See you in the next lecture, where we'll be discussing prosthetic heart valves.