Cardiac tamponade: causes and treatments
Cardiac tamponade or pericardial tamponade is a medical emergency. It consists of the accumulation of fluid or blood around the myocardium, which is the muscular layer of the heart. This liquid puts excessive pressure on the organ, compromising its movement.
The heart is the organ in charge of pumping oxygenated blood to all the organs and tissues of the body. Cardiac tamponade makes it unable to beat with enough force and efficiency. That is why it can be life threatening.
This problem is a relatively common situation that needs to be dealt with urgently. In this article we explain everything you need to know about the condition and how to identify it.
What is cardiac tamponade?
Cardiac tamponade is a serious disturbance in the functioning of the heart. What happens is that fluid or blood accumulates inside the pericardium.
In order to understand cardiac tamponade, one must first know certain anatomical features of the organ. The heart is made up of three layers: the endocardium, myocardium, and pericardium.. The endocardium is the innermost one, the one that lines the heart chambers.
The myocardium, for its part, is the muscular layer. That is, the one that allows blood to be pumped to all parts of the body. The pericardium is a kind of fibrous membrane that consists of two layers, between which there is a virtual space that can be filled with fluid.
In cardiac tamponade, fluid accumulates between the two layers of the pericardium.. The amount is such that the heart is pressed and cannot be stretched. Therefore, it cannot fill with blood or pump it.
It is important to distinguish between pericardial effusion and cardiac tamponade, because they are similar situations, but of different severity. According to Heart Surgeons, pericardial effusion refers to an increase in the volume of pericardial fluid.
However, it can be small or large and does not have to affect heart function. When talking about cardiac tamponade reference is made to a large spill, up to 2 liters, which compromises the function.
What are the symptoms?
Cardiac tamponade causes the heart to not be able to distend enough to fill its chambers with blood. This, in turn, causes less oxygenated blood to be expelled with each heartbeat or with less force.
In this way, the blood does not circulate correctly. There are 3 very characteristic signs of cardiac tamponade that are called Beck's triad:
- Decreased heart sounds or muffled sounds.
- Low blood pressure, which can lead to shock.
- Dilation or bulging of the neck veins.
In addition, tamponade produces a series of symptoms derived from this lack of perfusion. For example, dizziness, fainting, and drowsiness are very common. The skin is usually cool and slightly cyanotic (bluish in color).
It is usual for the pulse to become weak and fast. In addition, patients are agitated and anxious, with shortness of breath. Pain may also appear in the chest, back, or radiating to the abdomen.
Causes of cardiac tamponade
Cardiac tamponade, as we have explained in the introduction, occurs as a result of a pericardial effusion. That is to say, fluid builds up between the two layers of the pericardium and pressure is put on the heart. This can happen, in turn, for multiple reasons.
According to the MSD Manual, the most common causes include aortic aneurysm, lung cancer and myocardial infarction. Also in the event of trauma, such as wounds from weapons or high intensity impacts.
The aortic aneurysm consists of the presence of a weakened area in the wall of this vessel. The area is more fragile, so it can lead to dissection. Dissection leads to blood extravasation.
Cardiac surgery can also be associated with cardiac tamponade. The same occurs with certain pathologies, such as pericarditis, tuberculosis or kidney failure.
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Risk groups and prevalence
Fortunately, cardiac tamponade is a rare situation. There are about 5 cases for every 10,000 hospital admissions.
However, there are certain pathologies or conditions that increase the risk of cardiac tamponade. For example, cancer. Specifically, the advanced lung is the one most associated with this problem.
Certain pathologies, such as heart failure or kidney disease are also risk factors. This is because they are associated with greater fluid retention, which can accumulate in the pericardium. The same is true for autoimmune disorders, such as lupus.
How is cardiac tamponade diagnosed?
The diagnosis of cardiac tamponade must be rapid, since it is a medical emergency. Therefore, in the first instance it is essential to look at the symptoms. A good physical examination, blood pressure measurement, and heart auscultation should be performed.
In addition, as explained in a study published in the Spanish Journal of Cardiology, there are a series of complementary tests that help confirm the diagnosis. One of them is the echocardiogram. It is a harmless test that allows you to observe the heart structure and the presence of fluid.
Computed tomography, cardiac MRI, and chest x-ray are also used. The first two are more accurate, while the X-ray helps to see if the organ is larger than normal or an unusual shape.
The electrocardiogram is usually used to check if there is any alteration in electrical activity. On the other hand, it is complemented with blood tests to see if there is damage to the myocardium. This is evidenced by the elevation of certain specific enzymes, such as troponin.
The person who suffers it can enter shock and even die. Therefore, it is necessary to try to drain the fluid that compresses the heart.
There are different techniques available for this. Ideally, start with the least invasive, such as pericardiocentesis. It has a lower risk of complications and a lower mortality rate. Consists in remove the fluid accumulated between the layers of the pericardium using a needle.
Another technique is pericardiectomy. It is a more complex option, in which part of the pericardium is removed. This allows fluid to drain out and reduces pressure on the heart.
Nevertheless, sometimes it is necessary to resort to open surgery. The procedure is called thoracotomy. It consists of opening the chest wall and manipulating the heart directly to drain the fluid or eliminate any defect.
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Cardiac tamponade is an emergency
Cardiac tamponade consists of a collection of fluid around the heart. The liquid produces a pressure on this organ that prevents it from expanding and filling with blood. Therefore, the heartbeat is ineffective in getting the blood to reach all parts of the body.
When this problem appears it is essential to establish treatment early. If not, the patient can enter shock and even die. That is why it is essential to know the warning signs and seek help urgently.
Pericarditis is inflammation of the pericardium, a sac that surrounds the heart. In most cases it does not produce serious consequences. Read more "