What to know about cardiac tamponade
In people with cardiac tamponade, also known as pericardial tamponade, fluid or blood builds up between the heart and the sac that surrounds the heart. This sac is called the pericardium.
The pericardium consists of two thin layers of tissue. This area usually contains a small amount of fluid to prevent friction between the layers.
However, an abnormally high level of fluid puts pressure on the heart and affects its ability to pump blood around the body properly. If the level of fluid builds up quickly, it can be life-threatening.
Doctors consider cardiac tamponade to be a medical emergency.
In this article, we discuss the causes and symptoms of cardiac tamponade. We also describe the treatment options and the outlook for people with this condition.
A buildup of fluid around the heart muscles causes cardiac tamponade.
Image credit: Blausen.com staff, 2014.
Cardiac tamponade results from the buildup of fluid between the layers of the pericardium. In acute cardiac tamponade, this fluid accumulation occurs quickly, while it happens slowly in subacute cardiac tamponade.
The most common causes of cardiac tamponade are:
- severe chest injury
- heart attack
- hypothyroidism, or an underactive thyroid
- inflammation of the pericardium, which is called pericarditis
- aortic dissection
- bacterial infection
- tuberculosis (TB)
- kidney failure
- lupus, an autoimmune condition
- the bursting of an aortic aneurysm, or a bulge in the aorta
Complications arising from heart surgery may also cause cardiac tamponade.
According to some research, cardiac tamponade is the cause of surgical reintervention in 0.1–6.0 percent of cardiac surgery cases.
Signs and symptoms
Cardiac tamponade impairs the ability of the heart to pump blood around the body. As a result, blood does not circulate properly, which can lead to chest pains and lightheadedness.
The three classic signs of cardiac tamponade, which doctors refer to as Beck's triad, are:
- low blood pressure in the arteries
- muffled heart sounds
- swollen or bulging neck veins, called distended veins
People with cardiac tamponade may also experience the following symptoms:
- a weak pulse
- bluish skin that is cool to the touch
- a rapid heart rate
- sharp pain in the chest, back, abdomen, or shoulder
- shortness of breath
A doctor may recommend an ECG to accurately diagnose cardiac tamponade.
To diagnose cardiac tamponade, a doctor will look for Beck's triad of medical signs. They will do this by checking the individual's blood pressure, listening to their heart, and examining the appearance of their veins.
The doctor is likely to carry out additional tests to support their diagnosis. These may include:
- Echocardiogram. Doctors commonly carry out an echocardiogram, or echo, if they suspect cardiac tamponade. This scan provides a detailed image of the heart, which may help the doctor detect fluid in the pericardial sac or a collapsed ventricle.
- Chest X-ray. An X-ray of the chest shows if the heart is abnormally large or an unusual shape due to fluid buildup.
- Electrocardiogram (ECG). This test allows the doctor to examine the electrical activity of the heart.
- Computerized tomography (CT) scan. A CT scan of the chest can confirm the presence of extra fluid in the pericardium.
- Magnetic resonance angiogram (MRA). An MRA uses a magnetic field and radio waves to detect any abnormalities in how the blood flows through the blood vessels of the heart.
The doctor may order blood tests to measure the levels of red and white blood cells too. Blood tests may also detect higher levels of specific enzymes that the body releases in response to damage to the heart muscle.
Is cardiac tamponade common?
Cardiac tamponade is not a common condition, but it can affect anyone.
A 2018 study reports 5 cases of cardiac tamponade per 10,000 hospital admissions (0.05 percent) in the United States.
People with certain medical conditions are more likely than the general population to experience cardiac tamponade, including people with:
- end-stage renal disease
- a history of heart failure
- lupus and some other autoimmune conditions
- malignant tumors
- injuries to the chest
As cardiac tamponade can result in shock or death, it always requires emergency medical treatment. This treatment involves draining excess fluid from around the heart.
A doctor may use the following methods to remove the fluid and reduce the pressure on the heart:
- Pericardiocentesis. The removal of fluid from the pericardium using a needle.
- Pericardiectomy. The surgical removal of part of the pericardium to relieve pressure on the heart.
- Thoracotomy. A surgical procedure that allows the draining of blood or blood clots around the heart.
According to some research, doctors should choose minimally invasive procedures, such as pericardiocentesis, as the first treatment option. Such options carry a less significant risk of complications and have lower mortality rates.
However, more complicated cases of cardiac tamponade will often require surgery, including a thoracotomy.
After surgery, the individual may receive the following as they stabilize:
- intravenous (IV) fluids to maintain normal blood pressure
- medications to increase blood pressure
- oxygen to reduce stress on the heart
Once the person is stable, the doctor will need to determine and treat the underlying cause of the cardiac tamponade to prevent further complications.
An early diagnosis can improve the outlook for people with cardiac tamponade.
The outlook for people with cardiac tamponade depends on:
- how quickly they receive treatment for the condition
- possible complications
- the underlying cause
People with a non-cancerous cause of cardiac tamponade have a mortality rate of less than 15 percent.
Cases in which cancer is the underlying cause have an estimated mortality rate of 80 percent within 1 year.
Prompt diagnosis and early treatment significantly improve the outlook for people with cardiac tamponade. Without treatment, the condition is fatal.
It is not possible to prevent all cases of cardiac tamponade. However, people can reduce their risk by doing the following:
- reducing exposure to bacterial or viral infections
- receiving treatment for medical conditions, such as lupus and hypothyroidism
- protecting heart health through a balanced diet and regular exercise
- attending regular medical checkups
- avoiding smoking
Cardiac tamponade is an uncommon but severe medical condition that can result in shock or death. It is vital that anyone who suspects that they have cardiac tamponade seeks emergency treatment.
The treatment for cardiac tamponade involves draining the excess fluid from the pericardium, stabilizing blood pressure, and treating the underlying cause.
People who receive prompt diagnosis and appropriate treatment generally have a better outlook.
Although it is not possible to prevent all cases of cardiac tamponade, people should be aware of their risk factors and discuss preventive methods with their doctor.