Cardiac tamponade, also known as pericardial tamponade (), is the buildup of fluid in the pericardium (the sac around the heart), resulting in compression of the heart. Onset may be rapid or gradual. Symptoms typically include those of obstructive shock including shortness of breath, weakness, lightheadedness, and cough. Other symptoms may relate to the underlying cause.Common causes of cardiac tamponade include cancer, kidney failure, chest trauma, myocardial infarction, and pericarditis. Other causes include connective tissues diseases, hypothyroidism, aortic rupture, autoimmune disease, and complications of cardiac surgery. In Africa, tuberculosis is a relatively common cause.Diagnosis may be suspected based on low blood pressure, jugular venous distension, or quiet heart sounds (together known as Becks triad). A pericardial rub may be present in cases due to inflammation. The diagnosis may be further supported by specific electrocardiogram (ECG) changes, chest X-ray, or an ultrasound of the heart. If fluid increases slowly the pericardial sac can expand to contain more than 2 liters; however, if the increase is rapid, as little as 200 mL can result in tamponade.Tamponade is a medical emergency. When it results in symptoms, drainage is necessary. This can be done by pericardiocentesis, surgery to create a pericardial window, or a pericardiectomy. Drainage may also be necessary to rule out infection or cancer. Other treatments may include the use of dobutamine or in those with low blood volume, intravenous fluids. Those with few symptoms and no worrisome features can often be closely followed. The frequency of tamponade is unclear.
This commonly occurs as a result of chest trauma (both blunt and penetrating), but can also be caused by myocardial infarction, myocardial rupture, cancer (most often Hodgkin lymphoma), uremia, pericarditis, or cardiac surgery, and rarely occurs during retrograde aortic dissection, or while the person is taking anticoagulant therapy. The effusion can occur rapidly (as in the case of trauma or myocardial rupture), or over a more gradual period of time (as in cancer). The fluid involved is often blood, but pus is also found in some circumstances. Surgery
One of the most common settings for cardiac tamponade is in the first 7 days after heart surgery. After heart surgery, chest tubes are placed to drain blood. These chest tubes, however, are prone to clot formation. When a chest tube becomes occluded or clogged, the blood that should be drained can accumulate around the heart, leading to tamponade. Pathophysiology
The pericardium, the double-walled sac surrounding the heart, consists of a fibrous pericardium layer on the outside and a double-layered serous pericardium on the inside. Between the two layers of the serous pericardium is the pericardial space, which is filled with lubricating serous fluid that prevents friction as the heart contracts. The outer layer of the heart is made of fibrous tissue which does not easily stretch, so once excess fluid begins to enter the pericardial space, pressure starts to increase. Consequently, the heart becomes compressed due to its inability to fully relax.If fluid continues to accumulate, each successive diastolic period leads to less blood entering the ventricles.