What is cardiac tamponade?

Cardiac tamponade is a medical emergency caused by the accumulation of pericardial fluid such as exudate, transudate, or blood in the pericardial sac of the heart; the accumulation of the fluid results in reduced cardiac filling and subsequent hemodynamic compromise.¹

Cardiac tamponade requires prompt clinical diagnosis and treatment to prevent cardiovascular collapse and cardiac arrest.

What are the causes of cardiac tamponade?

The pericardium is a sac that encloses the heart and the roots of the great blood vessels and consists of visceral and parietal components. The pericardial space between the two layers contains up to 50 ml of serous fluid, lubricating and protecting against infection.

The causes of pericardial fluid overload that cause cardiac tamponade are:²

• Contageous
• Idiopathic
• Neoplastic disease
• Post-cardiac surgery
• Immuno-inflammatory
• Trauma
• Kidney failure
• Aortic dissection
• Others (chronic renal failure, thyroid disease, amyloidosis)

The most common causes of tamponades are pericarditis, iatrogenic (invasive cardiac procedures and postoperative) and malignancy. Other rare causes include collagen diseases (a group of conditions of unknown origin mainly involving connective tissue, such as systemic lupus, rheumatoid arthritis, erythematosus and scleroderma), radiation, aortic dissection, uremia, post-myocardial infarction and bacterial infection. Causes of effusion with increased chances of progression to tamponade include bacterial, fungal, HIV (human immunodeficiency virus) infections, bleeding, and cancer. Infectious diseases are among the most common causes of pericardial tamponade in patients. With an increasing number of cardiac interventional procedures, such as cardiac ablation, device electrode implantation, and percutaneous coronary intervention, the risk of hemopericardium appears to increase.

The patients have a better tolerance for the pericardial fluid that builds up slowly than with rapid accumulations.

Symptoms of cardiac tamponade

The symptoms of cardiac tamponade vary depending on the duration of pericardial fluid overload. Rapid accumulation of pericardial fluid leads to a sharp increase in pericardial pressure, while slower accumulation of pericardial fluid takes longer to reach critical or symptomatic pericardial pressure.

Thus, the hemodynamic effect of an effusion ranges from none or mild to cardiogenic shock, leading to a clinical presentation ranging from acute to subacute. Acute or rapid cardiac tamponade is a type of cardiogenic shock that occurs within minutes. The symptoms are the immediate onset of cardiovascular collapse, associated with chest pain, tachypnea and dyspnoea. The decrease in cardiac output causes hypotension and cool extremities.

Jugular venous pressure increases, which may appear as venous distension in the neck and head. Acute cardiac tamponade is usually caused by bleeding due to trauma, aortic dissection, or is iatrogenic.

Chronic pericardial fluid accumulation or subacute cardiac tamponade is characterized by patients being more asymptomatic in the early phase. However, when pressure increases above the pericardial stretch point, patients complain of dyspnea, chest discomfort, peripheral edema, fatigue, or fatigue. All these symptoms are due to increased pericardial pressure and inadequate cardiac output.

How to diagnose cardiac tamponade?

The diagnosis of cardiac tamponade is based on the patient’s history and physical examination. Commonly used diagnostic tools are:³

• ECG can help detect cardiac tamponade due to the heart swinging in a fluid-filled pericardium. The most common ECG finding for cardiac tamponade is sinus tachycardia (increased heart rate).
• Echocardiography is the best imaging technique for use at the bedside, which can confirm a pericardial effusion and determine its extent. It also determines the cause of the impairment of cardiac function (diastolic collapse of the right ventricle, systolic collapse of the right atrium, plethoric IVC).
• A chest x-ray showing an enlarged heart may be strongly suggestive of pericardial effusion if a previous chest x-ray showing a normal cardiac silhouette (the loss of normal boundaries between the thoracic structures) is available for comparison.
• A CT scan of the chest can also pick up pericardial effusion.
• Blood tests that can help diagnose cardiac tamponads include creatine kinase levels, antinuclear antibody testing, renal profile, coagulation profile, HIV testing, ESR, and PPD skin test.

Management of cardiac tamponade

Before initiating decompression of the pericardium, the patient should receive oxygen, volume expansion, and bed rest with legs elevated. Positive pressure mechanical ventilation should be bypassed if possible to further reduce venous return and worsen symptoms.

Once tamponade is diagnosed, urgent pericardiocentesis should be a priority treatment. In preparation for pericardiocentesis, intravenous hydration and positive inotropes may be used temporarily, but should not replace or delay pericardiocentesis.

The risks and benefits of needle centesis should be considered based on the patient’s diagnostic results.

How is cardiac tamponade treated?

Cardiac tamponade is a medical emergency requiring rapid removal of pericardial fluid and should be treated in an intensive care unit. ⁴

• The most common procedure is to perform pericardiocentesis using a needle and catheter to remove the fluid or surgically drain the pericardial sac. Emergency subxiphoid percutaneous drainage is another safest method for emergency pericardiocentesis. It is performed under the guidance of echocardiography. Removal of excess fluid can often improve hemodynamics significantly, but leaving a catheter in the pericardium can assist with further drainage.

• Open surgical drainage is usually not necessary. However, an available surgical procedure is needed if intrapericardial hemorrhage, lumpy pericardium, or needle centesis is difficult or ineffective. Surgical options include creating a pericardial window or removing the pericardium. Emergency department resuscitative thoracotomy and pericardial sac opening is another therapy used in traumatic arrest patients with suspected or confirmed cardiac tamponade. These options are preferable to needle pericardiocentesis for traumatic pericardial effusion.

• In patients with large effusions with minimal or no sign of hemodynamic compromise, therapy is directed at the underlying cause. Patients with idiopathic pericarditis and mild tamponade can be treated with nonsteroidal anti-inflammatory drugs (NSAIDs) and colchicine. The same treatment plan could be carried out in patients with connective tissue or inflammatory diseases. Unfortunately, there are no proven medical therapies to reduce an isolated effusion. NSAIDs (such as aspirin, ibuprofen, and steroids), colchicine, and corticosteroids are generally ineffective without inflammation.

• Pericardiocentesis alone is necessary to resolve large effusions, but recurrences are common. Surgical pericardiectomy or a less invasive option (i.e., pericardial window) should be considered if fluid reaccumulates, becomes localized, coagulopathy is present, or biopsy material is required. Localized pericardial effusions due to hemorrhage are difficult to drain sufficiently without surgical intervention. Surgical drainage may be necessary to correct the cause of the bleeding.

In any case, treatment must be individualized and careful clinical assessment is imperative.

What are the possible complications of cardiac tamponade?

If cardiac tamponade is treated quickly, it often does not lead to complications. If left untreated, it can lead to shock and other serious problems due to shock. For example, the decreased blood flow to the kidneys during shock can cause kidney failure. Untreated shock can also result in organ failure and death.

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