The heart is surrounded by a sac called the pericardium. When this sac becomes filled with fluid, the liquid presses on the heart, preventing the lower chambers of the heart from properly filling with blood, resulting in a condition called cardiac tamponade. Because the lower chambers (the ventricles) cannot fill with the correct amount of blood, less than normal amounts of blood reach the lungs and the rest of the body. This condition is very serious and can be fatal if not treated.
Blunt or penetrating injury from trauma to the chest or heart can cause largeamounts of blood to fill the pericardium, resulting in cardiac tamponade. Fluid can collect inside the pericardium and compress the heart when the kidneys do not properly remove waste from the blood or when the pericardium is damaged by infection or cancer. Tamponade can also occur during open-heart surgery.
When tamponade occurs because of trauma, the sound of the heart beats can become faint, and the blood pressure in the arteries decreases, while the bloodpressure in the veins increases. In cases of tamponade caused by more slowlydeveloping diseases, shortness of breath, a feeling of tightness in the chest, increased blood pressure in the large veins in the neck (the jugular veins), weight gain, and swelling caused by fluid retention can occur.
When cardiac tamponade is suspected, accurate diagnosis can be life-saving. The most accurate way to identify this condition is by using a test called anechocardiogram, or ultrasound of the heart. This test uses sound waves to create an image of the heart and its surrounding sac, making it easy to visualize any fluid that has collected inside the sac.
If the abnormal fluid buildup in the pericardial sac is caused by cancer or kidney disease, drugs used to treat these conditions can help lessen the amount of fluid collecting inside the sac. Drugs that help maintain normal blood pressure throughout the body can also help this condition; however, these drugs are only a temporary treatment. The fluid within the pericardium must be drained out to reduce the pressure on the heart and restore proper heart pumping.
The fluid inside the pericardium is drained by inserting a needle through thechest and into the sac itself, and drawing the fluid out. This procedure iscalled pericardiocentesis. In severe cases, a tube (catheter) can be insertedinto the sac or a section of the sac can be surgically cut away to allow formore drainage.
Cardiac tamponade is life-threatening. However, drug treatments can be helpful, and surgical treatments can successfully drain the trapped fluid, though it may reaccumulate. Some risk of death exists with surgical drainage of the accumulated fluid.