Cardiac tamponade is a serious medical condition in which blood or fluids fill the space between the sac that encases the heart and the heart muscle, placing extreme pressure on the heart. The resulting pressure prevents the heart's ventricles from expanding fully and keeps the heart from functioning properly. When this happens, the heart cannot pump enough blood to the rest of your body, which can lead to organ failure, shock, and even death. According to the National Center for Biotechnology Information (NCBI), this condition occurs in approximately two out of every 10,000 people. (NCBI, 2012)
Cardiac tamponade is a medical emergency. If you are someone you know begins experiencing symptoms, seek medical help immediately.
What Causes Cardiac Tamponade?
Cardiac tamponade is most often the result of penetration of the pericardium, the thin, double-walled sac that surrounds the heart. The cavity around the heart can fill with enough blood or other bodily fluids to compress the heart. As the fluid presses on the heart, less and less blood can enter, and as a result, less oxygen-rich blood can be pumped out to the rest of the body. Eventually, the lack of blood getting to heart and the rest of your body can cause shock, organ failure, and cardiac arrest.
Causes of pericardial penetration or fluid accumulation might include:
- gunshot or stab wounds
- blunt trauma to the chest from a car or industrial accident
- accidental perforation after cardiac catheterization, angiography, or insertion of a pacemaker
- punctures during placement of central lines, a type of catheter used to administer fluids or medications
- invasion of the sac by breast, lung, or other cancers
- a ruptured aortic aneurysm
- pericarditis—inflammation of the pericardium
- lupus, an inflammatory disease in which the immune system mistakenly attacks healthy tissues
- high levels of radiation to the chest
- hypothyroidism, which increases risk for heart disease
One of the major risk factors for cardiac tamponade is the use of chest tubes after heart surgery. These tubes are often used to allow fluids to drain. However, they may become clogged with blood clots, and this will allow fluids to accumulate in the heart cavity.
What Are the Symptoms of Cardiac Tamponade?
This condition may manifest the following symptoms:
- anxiety and restlessness
- low blood pressure and weakness
- chest pain radiating to your neck, shoulders, or back
- trouble breathing or taking deep breaths
- rapid breathing
- discomfort that is relieved by sitting or leaning forward
- fainting, dizziness, and loss of consciousness
How Is Cardiac Tamponade Diagnosed?
Cardiac tamponade often has three characteristic signs that your doctor will recognize during a physical exam. These signs are commonly referred to as Beck’s triad and include:
- low blood pressure and weak pulse because the volume of blood your heart is pumping is reduced
- extended neck veins because they are having a hard time returning blood to the heart
- a rapid heart beat combined with muffled heart sounds due to the expanding layer of fluid inside the pericardium
If cardiac tamponade is suspected, your doctor will conduct further tests to confirm the diagnosis. An echocardiogram (heart ultrasound) can detect whether the pericardium is distended and if the ventricles have collapsed due to low blood volume. Chest X-rays may show an enlarged, globe-shaped heart that is characteristic of cardiac tamponade. Other diagnostic tests may include:
- thoracic computed tomography (CT) scan to look for fluid accumulation in the chest or changes to the heart
- magnetic resonance imaging (MRI) scan of the chest to view the structure of the heart
- coronary angiography to view how the blood is flowing through the heart
- electrocardiogram to assess the heartbeat
How is Cardiac Tamponade Treated?
Cardiac tamponade is a medical emergency that requires hospitlization. The treatment of cardiac tamponade is generally twofold: relieving pressure on your heart and then treating the underlying condition. Initial treatment involves getting you stabilized.
Your doctor will also drain the fluid from your pericardial sac, typically with a needle in a procedure called pericardiocentesis. A more invasive procedure called a thoracotomy may be performed to drain blood or remove blood clots if you have a penetrating wound. A portion of your pericardium may also be removed to help relieve pressure on your heart.
You will also be given oxygen, fluids, and medications to increase your blood pressure.
Once the tamponade is under control and you are stabilized, your doctor may perform additional tests to determine the underlying cause of your condition.
What is the Outlook for Cardiac Tamponade?
The long-term outlook for surviving cardiac tamponade depends on how quickly the diagnosis can be made, the underlying cause of the tamponade, and any subsequent complications. If cardiac tamponade is quickly diagnosed and treated, your outlook is fairly good. However, If blood and other fluids are not removed from the pericardium promptly, it can lead to heart failure, shock, and death.