What is cardiac tamponade?
Cardiac tamponade is a condition in which the pressurized protective sack around the heart (pericardium) fills with blood and compromised heart function.
Cardiac tamponade is a life-threatening condition caused by excessive fluid accumulation in the protective sac (pericardium) around the heart. The fluid exerts pressure on the heart and impairs its ability to pump blood.
What are three signs of cardiac tamponade?
The three classic signs (Beck’s triad) that indicate cardiac tamponade are:
- Low pressure in the arteries (hypotension)
- Bulging (distended) neck veins
- Muffled heart sounds
Apart from the above-mentioned signs, the doctor may use tests such as echocardiogram, a CT scan, magnetic resonance angiogram (MRA) and electrocardiogram to confirm the diagnosis of cardiac tamponade, its extent, and severity.
What are the signs and symptoms of cardiac tamponade?
The symptoms of cardiac tamponade vary with the underlying cause of the fluid accumulation and severity of the condition. Besides Beck’s triad, other symptoms and signs may include:
- Chest pain radiating to neck, shoulders and back
- Chest pressure
- Breathing difficulties
- Shortness of breath
- Rapid breathing
- Restlessness and anxiety
- Clammy and cold extremities
- Decreased urine output
- Elevated heart rate (tachycardia)
- Increased pressure in the jugular vein
- Abnormally large drop in systolic pressure and pulse while inhaling (pulsus paradoxus)
What causes cardiac tamponade?
The pericardial sac is a thin, two-layered sheath surrounding the heart, normally containing a small amount of fluid. When large amounts of blood or other fluids accumulate in the pericardial space between the layers of pericardium, it is known as pericardial effusion. This exerts pressure on the heart and compresses it, resulting in cardiac tamponade.
Cardiac tamponade is usually the result of injury to the pericardium due to trauma or other underlying diseases. Malignant diseases are the most common reason for cardiac tamponade. Other causes of cardiac tamponade include:
- Rupture of aortic aneurysm
- Chest injury from stabbing or gunshot
- Trauma to the chest from an accident
- Cardiac and other surgeries in the chest region
- Accidental perforation due to procedures like placement of pacemaker or catheter, and angiography
- Heart attack and heart failure
- Inflammation of the pericardium (pericarditis) caused by viral or bacterial infections
- Radiation treatment to the chest and radiofrequency ablation
- Final stages of lung and other cancers
- High level of urea in the blood (uremia) due to kidney disease/failure
- Human immunodeficiency virus (HIV) infection
- Certain drugs which cause fluid to develop
- Connective tissue diseases such as
- Rheumatoid arthritis
- Still disease
- Genetic muscle degeneration disease (Duchenne muscular dystrophy)
- Anticoagulant treatment like blood thinners
What is the difference between pericardial effusion and cardiac tamponade?
Pericardial effusion is accumulation of fluid that increases the pressure in the pericardial cavity. When the pressure increases sufficiently to adversely affect the heart’s function, cardiac tamponade results.
What is the treatment for cardiac tamponade?
Cardiac tamponade is a medical emergency requiring immediate treatment in an intensive care unit. The underlying cause must be treated along with urgent drainage of the fluid. A cardiologist or cardiothoracic surgeon treats the patient and the first line of treatment is typically:
- Oxygen to reduce the heart’s workload
- Drugs to improve heart function and reduce blood pressure
- IV fluids, blood or plasma to increase the volume of blood in circulation (volume expansion)
- Bed rest with leg elevation
- Drainage of pericardial fluid (pericardiocentesis)
Positive pressure ventilation is avoided as it can further aggravate symptoms. Once the patient is stabilized, the doctor performs further tests to determine the underlying condition and treat it.
Patients who do not stabilize with the above procedures, or those with recurrent tamponade might need surgery and further treatment.
What is the prognosis for cardiac tamponade?
The key to reducing deaths from cardiac tamponade is prompt diagnosis and treatment. The survival rate drops with each delay in treatment, and without treatment it is fatal. In patients with cardiac tamponade caused by malignant disease, the mortality rate is over 75% within one year.