Definition Cardiac tamponade is a build-up of fluid in the pericardium, which is the thin membrane around the heart. This build-up obstructs the inflow of blood so that the ventricles, or lower chambers of the heart, cannot fill.
What is going on in the body? The pericardium normally contains a very small amount of fluid. It plays an important role in:
helping the atria, or upper chambers of the heart, fill with blood while the heart is beating
maintaining the position of the heart within the chest
minimising friction between the heart and surrounding structures
Chest trauma, such as a crush injury, and a variety of diseases can cause fluid to build up in the pericardium. The accumulated fluid can be in the form of blood or other body fluids. The fluid around the heart restricts the ventricles' ability to fill with blood. If the build-up of fluid occurs slowly over time, then large amounts of fluid can collect. However, if fluid collects suddenly, even small amounts may be fatal.
What are the signs and symptoms of the condition? Although the onset of cardiac tamponade can be sudden, it commonly occurs slowly. The symptoms increase with the amount of blood in the pericardium. As the heart fails to function as an efficient pump, these symptoms appear:
If the cardiac tamponade is not treated, the person may die.
What can be done to prevent the condition? Early treatment of any underlying heart disease or infection can help prevent cardiac tamponade. Drainage of fluid from the pericardium before too much builds up can also prevent tamponade.
How is the condition diagnosed? The diagnosis can be made by the presence of abnormal pulses and an abnormal electrocardiogram, or ECG. A chest x-ray may show changes in the shape of the heart. Echocardiography, an ultrasound of the heart, or invasive tests such as cardiac catheterisation can confirm the diagnosis.
What are the long-term effects of the condition? If the tamponade is not discovered, the fluid build-up into the pericardium will finally stop the heart from filling properly, and death may result.
What are the risks to others? There are no risks to others.
What are the treatments for the condition? A needle placed into the pericardium can drain the fluid. Sometimes a chest tube is left in place to allow continuous drainage.
What are the side effects of the treatments? The needle drainage of fluid out of the pericardium is associated with an increased risk of infection and perforation of the wall of the heart or lung.
What happens after treatment for the condition? After treatment, the person is watched carefully because fluid may build up again. If that happens, the procedure will need to be repeated. The underlying disease must be aggressively treated.
How is the condition monitored? If the tamponade is caused by a sudden chest trauma and is successfully drained, then the risk of more fluid build-up decreases. Treatment of any underlying heart infection must be maintained to make sure that fluid does not build up again.
Author: Eric Berlin, MD Reviewer: HealthAnswers Australia Medical Review Panel Editor: Dr David Taylor, Chief Medical Officer HealthAnswers Australia Last Updated: 1/10/2001 Contributors Potential conflict of interest information for reviewers available on request
