2. Description of
condition Cardiac tamponade is a medical emergency caused by a
buildup of fluid or air in the pericardium putting pressure
on the heart and preventing the heart from expanding
properly.
A pericardial effusion is a progressive accumulation of
fluid, pus, blood, or gas in the pericardial cavity. Pericardial
effusion happens slowly, allowing the heart to adapt to the
slow increase in pressure. When too much pressure
accumulates too quickly, a pericardial effusion can result
in cardiac tamponade.
3. Causes Cardiac tamponade can be caused by a rapid
accumulation of fluid in the pericardium. Pericardial
effusion can also lead to cardiac tamponade.
Causes of acute cardiac tamponade:
- Complication of cardiac surgery (eg aortic
dissection)
- Chest trauma (stab wound, blunt trauma, etc)
- Rupture of weakened ventricle after an MI
- Acute pericarditis
- Ruptured aorta
Causes of pericardial effusion:
- Long-term pericarditis
- Pericardial infection
- Cancer
5. Signs and
Symptoms
Possible findings on physical exam:
Beck’s Triad:
- Hypotension
- JVD
- Diminished heart sounds
Chest Pain
Dyspnea
Cough
Tachycardia
Pulsus paradoxus
6. How diagnosis is
made ECG - Low voltage ECG
CXR - Will see enlarged cardiac silhouette, fluid
in lungs
Echo - High intrapericardial pressure may
collapse RA and RV on imaging.
Cardiac CT - will demonstrate pericardial fluid
and pericardial thickening
8. CXR
Chest radiographs may not be useful early in the
course of the process, since at least 200 mL of
pericardial fluid must accumulate before visible
enlargement of the cardiac silhouette occurs
https://pubs.rsna.org/doi/10.1148/rg.276065002
12. Echocardiogram
Diagnostic.
Will see signs related to problems with filling
of the heart
1. Pericardial effusion
2. Diastolic collapse of the right atrium
3. Diastolic collapse of the right ventricle
4. Swinging heart
5. Others
19. Role of Computed
Tomography
Echocardiography is first line imaging for tamponade
CT does have some advantages:
-Larger field of view
-Less operator dependent
-Lower rate of false-positive findings
-Accurate identification of cause or other pathologic
conditions and exact location of fluid
20. CT CT provides information about the possible nature of
pericardial effusions based on the measurements of
the collection.
Possible CT findings in tamponade:
- Superior vena cava enlargement: diameter
similar to or greater than that of the adjacent
thoracic aorta
- Inferior vena cava enlargement: diameter
greater than twice that of the adjacent
abdominal aorta
- Hepatic and renal vein enlargement
- Flattened heart sign
- Angulation of the interventricular septum
https://pubs.rsna.org/doi/10.1148/rg.276065002#F8
21. CT CT provides information about the possible nature of
pericardial effusions based on the measurements of
the collection.
Causes of tamponade demonstrated on CT:
- Malignant pericardial disease
- Other cancers
- Penetrating trauma
- Aortic dissection and aneurysm rupture
- Mediastinal pathology
- Tuberculosis
26. Conclusion Treatment for tamponade is to drain the pericardial
fluid. This can be done under echocardiographic,
fluoroscopic, or CT guidance.
Echocardiography is the first line imaging in patients
with suspected tamponade
CT can be useful if echocardiographic findings are
inconclusive
27. References
Hernández Castillo, A. Pericardial Tamponade. Osmosis.
https://www.osmosis.org/answers/pericardial-tamponade
Pérez-Casares, A., Cesar, S., Brunet-Garcia, L., &
Sanchez-de-Toledo, J. (2017). Echocardiographic
Evaluation of Pericardial Effusion and Cardiac
Tamponade. Frontiers in pediatrics, 5, 79.
https://doi.org/10.3389/fped.2017.00079
Pericarditis. (2019, May 3). Cleveland Clinic.
https://my.clevelandclinic.org/health/diseases/17353-
pericarditis
Restrepo, C. S., Author Affiliations1From the Department
of Radiology, Bogaert, J., Dreizin, D., Restrepo, C. S., &
Co, S. J. (2007, November 1). @RadioGraphics.
RadioGraphics. Retrieved October 17, 2021, from
https://pubs.rsna.org/doi/10.1148/rg.276065002.
It can also be classified by onset (acute, subacute, chronic)
By size (mild, moderate, large)
And distribution (circumferential = around the heart, or loculated = confined to a fixed pocket in the pericardium)
This diagram shows the pressure-volume curve for the pericardium. The horizontal dotted line is the limit of pericardial stretch, which is when cardiac tamponade occurs. There is also a pericardial reserve volume, which reflects the ability of the heart to compensate for an increase in fluid.
In the graph on the left, there is a rapid increase in pericardial effusion. The heart cannot adapt, so the compensatory reserve volume is small. Once reached, there is a steep rise in pressure. The pericardial pressure reduces diastolic compliance and decreases stroke volume.
In the pressure-volume curve on the right, the pericardial effusion happens more slowly, and the pericardial reserve volume is a bit larger. Once reached, there is a slower increase in the pressure, even once cardiac tamponade occurs. The pericardium can accommodate volumes as large as 1500 mL without hemodynamic compromise.
Leads to signs and symptoms related to a heart which cannot expand properly because it is being compressed by the fluid around it.
Results in restricted venous return and restricted filling of cardiac chambers. Leads to reduced stroke volume. HR increases (to compensate). Decreased CO. Reduced blood pressure.
Not a chronic process, so you don’t see symptoms of right heart failure (edema, ascites)
Pulsus paradoxus is defined as a fall of systolic blood pressure of >10 mmHg (mm mercury) during the inspiration
ECG Can possibly be used to detect distinct rhythm patterns, which can help you “rule in” cardiac tamponade.
ECG is not the best, but can help lead you towards tamponade.
CXR will be ordered when this patient is in the ED, and is usually ordered for anyone with chest symptoms.
Echo is primary method to observe pericardial effusion. Echo is diagnostic
So this is a flow chart to help the practitioner rule in or rule out tamponade.
(Click slide once) as you see one of the first tests you should do is an echo
(click slide again) and if echo isn’t convincing then you can do a CT to get a better idea if its tamponade or not.
Also note how EKG and CXR are not on this flow chart, however, depending on how the patient presents and in what setting they’re in (ED, inpatient, outpatient) the practitioner will utilize the different resources they have.
Quick look at a normal CXR
(click once to show labeled CXR)
Ellipse drawn over the heart demonstrates a "globular" configuration, also called a water bottle sign. One technique used is measuring the cardiothoracic ratio. Cardiac diameter divided by the diameter of the thorax. in this case yielding a ratio of 70%. Not the best method, because ideally you would want to compare this Xray with a previous normal chest xray of the patient. And again, CXR can help you rule in tamponade, but echo is diagnostic
So i know this definitely doesn’t look like any water bottle that we’re used to seeing, but I think it refers to the old canteens they used 100 years ago (click once)
The number of abnormal echo signs of tamponade will increase as the clinical severity of the pericardial effusion progresses.
Also, the lower pressure cardiac chambers (atria) are affected before the higher pressure ventricles.
Others refers to IVC plethora
Normal parasternal short axis view of the heart
This image is showing collapse of the right ventricle.
Big red arrow is pointing to the fluid around the heart
The arrow right next to that is just pointing at the collapsed right ventricle
And the arrow on the bottom (idk if you can see it) is showing you that this echocardiogram snapshot is take right after the P wave which corresponds to atrial contraction, so the right ventricle should be big and filled with fluid, but the ventricle is compressed by the fluid around it.
Apical 4 chamber view
And this a great 1 min video that clearly demonstrates the effusion and the heart swinging you might see on echo.
Advantages of CT for cardiac tamponade include a larger field of view to assess the entire chest. This can help rule out other abnormalities in the mediastinum, lungs, or other adjacent structures as well as the ability to see pericardial calcification.
CT is also less operator dependent.
High-quality motion-free images can be taken which could be useful in patients with limited breath-holding capacity
CT has a lower rate of false-positive findings than echocardiography because it can more accurately distinguish other pathologic conditions that could cause pericardial effusion, like lower lobe atelectasis, intracardiac masses, or mediastinal lesions. CT also more accurately shows clots, distinguishes fluid collections from pericardial thickening, determines a more exact location of fluid in the anterior and posterior space and identifies loculations.
Enlargement of the vena cava is not specific for tamponade but it is sensitive (catches 92% of cases)
The so-called flattened heart sign occurs when intrapericardial pressure is high enough to produce a transient reversal of transmural left ventricular pressure. On CT, it looks like a flattening of the anterior surface of the heart with a decreased anteroposterior diameter.
Angulation or bowing of the interventricular septum is not specific for tamponade
Malignant pericardial disease can be seen as pericardial thickening, masses arising from the pericardium, and changes in the normal tissue planes
Other cancers that may cause tamponade include lymphoma or small cell lung cancer, and esophageal malignancies
Trauma can be caused by surgery or blunt injury with a sternal fracture
Mediastinal pathologic conditions that may cause tamponade include a malignancy
Case courtesy of Dr Sarah Kalus, Radiopaedia.org, rID: 46015
This image shows the flattened anterior surface of the heart (arrow). This was a 44yo M with a hx of lung cancer who presented to the ED with SOB, tachycardia, and tachypnea.
This is an image from a 30yo M with Immunoblastic T-cell lymphoma with pleural and pericardial involvement. This is a contrast-enhanced CT image. You can see compression of the heart both at the anterior (arrow) and posterior (arrowhead) surfaces by neoplastic tissue. This patient also has bilateral pleural effusions.
This last image is a 38-year-old man who presented after a motor vehicle accident. This is also a contrast-enhanced CT image. The arrow is pointing to an abnormal bowing of the interventricular septum toward the left ventricle with an associated large pericardial effusion.
