CARDIAC TAMPONADE

The heart primarily serves one function–to pump blood. The heart is located in the chest and is made up of muscle that contracts. Two layers of connecting tissue, called the pericardium, surround the heart muscle. The pericardium maintains the heart in its anatomic position. The pericardium does not allow the heart to move excessively or rub up against other structures with any body changes. In between the two layers of the pericardium is fluid called pericardial fluid. Normally the pericardium carries no more than 50 ml of fluid (approximately 10 teaspoons). Cardiac tamponade is compression of the heart by fluid within the pericardium, impairing the heart's ability to relax after contraction.

Pericardial tamponade can be acute, or sudden, and usually results from trauma such as a penetrating knife wound or from a motor vehicle accident, with the chest hitting the steering wheel and resulting in a tear of the main artery leaving the heart (aortic dissection). Other possible causes of acute cardiac tamponade include rupture of the heart muscle after a heart attack or holes made in the heart during a procedure (such as placement of a pacemaker). Pericardial tamponade can also be chronic, or gradually occurring. The most common causes of chronic pericardial tamponade are cancers (breast, lung, lymphoma), kidney failure, underactive thyroid (myxedema), and infections (viral, bacterial, fungal, tuberculosis). Depending on the cause, some cases of pericardial tamponade can be cured.

Pericardial tamponade is usually detected by an echocardiogram (ultrasound of the heart). The echocardiogram can detect as little as 20 ml or 4 teaspoons of fluid within the pericardial sac.

In some instances, a needle placed through the chest into the pericardium, called pericardiocentesis, is recommended. This allows the physician to remove the fluid as part of the treatment and allows the pathologist to examine the fluid under a microscope to make a diagnosis.

Most patients with acute pericardial tamponade are gravely ill and have a low blood pressure along with difficult-to-hear heart sounds. This is considered a surgical emergency.

Patients with chronic pericardial tamponade are short of breath. They have a fast heart rate and can have a low blood pressure with abnormal heart sounds called friction rubs. In either case, the fluid surrounding the heart must be removed to improve the heart's ability to pump.

Acute pericardial tamponade is a surgical emergency. A cardiothoracic surgeon will most likely be involved in your care. The specific cause of the tamponade dictates what the treatment will be. For example, in aortic dissection, the tear in the aorta must be sutured closed and the blood within the pericardial sac must be removed.

Treatment of patients with chronic pericardial tamponade depends on the cause. In the case of cancer, specific chemotherapy drugs will be recommended after the type of cancer has been diagnosed. Antibiotics or antifungal drugs can be used if the cause of the pericardial tamponade is due to a bacterial or fungal infection.

• Remember, cardiac tamponade can be life-threatening. Emergency treatment is generally required, and intensive care monitoring is needed.
• Understand that pericardial tamponade does not allow the heart muscle to relax after it contracts. This results in a small amount of blood pumped out by the heart and decreases the heart's ability to maintain blood pressure. This can lead to shock and death if the fluid is not removed emergently and expeditiously.

• Don't forget that a cardiothoracic surgeon (a surgeon who specializes in diseases of the heart and blood vessels) and a cardiologist (a medical person who specializes in diseases of the heart) are the right people to get involved when dealing with pericardial tamponade.
• Don't miss your follow-up appointments after you have been discharged from the hospital. In some situations, the pericardial fluid can return, and this can be detected by follow-up echocardiograms.

• If you are short of breath.
• If you have chest pain with fever, chills, and sweats.

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