Pericardial effusion Cardiac tamponade

The pericardium is a two-layer envelope that surrounds the heart, constituting its outermost layer. Between these two layers is a small amount of fluid (intrapericardial) that constantly lubricates the surfaces and allows the heart to move easily during contraction.

The accumulation of fluid between these two membranes is known as a pericardial effusion. When the accumulation of fluid is in sufficient quantity to significantly obstruct the entry of blood into both ventricles, what is known as cardiac tamponade occurs.

How is it produced?

The role of the pericardium is to protect and help facilitate the functioning of the heart. On the one hand, it limits the distension of the heart in situations of excess volume and, on the other hand, it contributes to the adequate filling of both ventricles. Ventricular filling is not significantly affected until a threshold is exceeded, above which there is an increase in intrapericardial pressure that reduces this filling. In cases of rapid accumulation of intrapericardial fluid, as occurs in acute pericardial effusion, there is an increase in pressure that makes it difficult for the ventricles to fill properly, causing cardiac tamponade.

The three most common causes of cardiac tamponade include tumors, pericarditis, and kidney disease.

Other causes of tamponade include bleeding after cardiac surgery, trauma, tuberculosis, and anticoagulant drugs.

Symptoms

Small or chronic pericardial effusion usually causes few symptoms and is often an incidental finding during X-ray or echocardiography.

Cardiac tamponade, if it occurs quickly, causes a picture of shock or collapse of the body, basically characterized by hypotension, respiratory distress, tachycardia, and drowsiness or drowsiness.

If it occurs more slowly, the symptoms can be similar to those of heart failure, including dyspnea or a sensation of shortness of breath and the accumulation of fluid in the abdomen and extremities.

Diagnosis

There are no specific laboratory tests to diagnose tamponade. This is based on the symptoms and signs that the patient presents and the verification of the effusion through imaging tests. Echocardiography is the first option to establish the diagnosis.

The most characteristic findings of tamponade are the presence of:

• Arterial hypotension
• Decreased heart sounds on auscultation.
• Dilatation of the veins in the neck due to the accumulation of blood from being able to enter the heart.
• blood pressure can drop when the person takes a deep breath. Peripheral pulses (pulse in the extremities) may be weak or absent.

Treatment

Small or chronic pericardial effusion usually does not require any treatment.

Cardiac tamponade is a medical emergency that always requires hospital care. Treatment is aimed at draining the accumulated intrapericardial fluid so that the heart can resume its normal pumping function.

Specific measures

Pericardiocentesis is the procedure of choice. This technique consists of inserting a long and thick needle under the sternum until accessing the pericardium under ultrasound control. Once the needle is in the intrapericardial space, the accumulated fluid is slowly withdrawn. Sometimes it is necessary to perform successive periocardiocentesis.

Further analysis of this fluid can help diagnose the cause of the tamponade.

Sometimes a part of the pericardium needs to be cut and removed, known as a surgical pericardiectomy or pericardial window.

Complementary measures:

• Throughout the process the patient must be monitored with control of their vital signs.
• Administration of oxygen.
• Administration of drugs may be necessary to maintain blood pressure.

Prevention

In most cases it cannot be prevented. When there is pericarditis or other pericardial diseases, ultrasound controls must be carried out to see if there is an effusion and its evolution.