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Cardiac Tamponade


Thomas G. Weiser

, MD, MPH, Stanford University School of Medicine

Reviewed/Revised Apr 2022 | Modified Sep 2022

Cardiac tamponade is accumulation of blood in the pericardial sac of sufficient volume and pressure to impair cardiac filling. Patients typically have hypotension, muffled heart tones, and distended neck veins. Diagnosis is made clinically and often with bedside echocardiography. Treatment is immediate pericardiocentesis or pericardiotomy.

Fluid in the pericardial sac can impair cardiac filling, leading to low cardiac output and sometimes shock Shock Shock is a state of organ hypoperfusion with resultant cellular dysfunction and death. Mechanisms may involve decreased circulating volume, decreased cardiac output, and vasodilation, sometimes... read more and death. If fluid accumulates slowly (eg, due to chronic inflammation), the pericardium can stretch to accommodate up to 1 to 1.5 L of fluid before cardiac output is compromised. However, with rapid fluid accumulation, as occurs with traumatic hemorrhage, as little as 150 mL may cause tamponade.

In trauma, the cause is more often a penetrating rather than blunt mechanism. The wound is often medial to the nipples (for anterior wounds) or the scapulae (for posterior wounds). Tamponade due to blunt trauma involves cardiac chamber rupture, which is typically fatal before patients can be brought for treatment.

Symptoms and Signs of Cardiac Tamponade

Classically, patients have Beck's triad, which consists of the following:

  • Hypotension

  • Muffled heart tones

  • Venous pressure increase (eg, neck vein distention)

However, hypotension has multiple potential causes in trauma patients, muffled heart tones can be difficult to assess during a noisy trauma resuscitation, and neck vein distention can be absent due to hypovolemia. Pulsus paradoxus Pulsus paradoxus Complete examination of all systems is essential to detect peripheral and systemic effects of cardiac disorders and evidence of noncardiac disorders that might affect the heart. Examination... read more Pulsus paradoxus , a decrease in systolic blood pressure during inspiration of > 10 mm Hg, is also suggestive, but again not easy to assess in a noisy setting.

Diagnosis of Cardiac Tamponade

  • Clinical evaluation

  • Often bedside echocardiography

Diagnosis can be difficult. Beck's triad is considered diagnostic but may not be present or easy to recognize. In addition, tension pneumothorax Pneumothorax (Tension) Tension pneumothorax is accumulation of air in the pleural space under pressure, compressing the lungs and decreasing venous return to the heart. (See also Overview of Thoracic Trauma.) Tension... read more Pneumothorax (Tension) also should be considered in patients with hypotension and neck vein distention, although this disorder typically causes markedly decreased breath sounds and hyperresonance on the affected hemithorax. E-FAST How To Do E-FAST Examination E-FAST (Extended Focused Assessment with Sonography in Trauma) is a bedside ultrasonographic protocol designed to detect peritoneal fluid, pericardial fluid, pneumothorax, and/or hemothorax... read more How To Do E-FAST Examination (Extended Focused Assessment With Sonography in Trauma) can be diagnostic and can be done during the initial evaluation and resuscitation but may be falsely negative. The diagnosis sometimes is suggested by unexplained failure to respond to volume resuscitation.

Treatment of Cardiac Tamponade

  • Pericardiocentesis

  • Pericardiotomy or creation of a pericardial window

Subxiphoid pericardiocentesis is done in unstable patients when cardiac tamponade is suspected. Electrocardiographic monitoring during the insertion needle for ST segment elevation (indicating contact with the epicardium and the need to withdraw the needle) is done if possible. Pericardiocentesis is a temporizing measure. Removal of as little as 10 mL of blood may normalize blood pressure. However, failure to aspirate blood does not exclude the diagnosis; fresh blood in the pericardium is often clotted.

Thoracotomy with pericardiotomy or establishment of a subxiphoid pericardial window are more definitive treatments, which are indicated in patients in whom the diagnosis is confirmed or strongly suspected. If adequately trained personnel are available and the patient is unstable and fails to respond to other resuscitative measures, a thoracotomy with pericardiotomy can be done at the bedside in the emergency setting. Otherwise, the procedure is done in the operating room as soon as feasible.

Key Points

  • Cardiac tamponade is most often caused by a penetrating wound medial to the nipples (for anterior wounds) or the scapulae (for posterior wounds).

  • The triad of muffled heart tones, hypotension, and neck vein distention is diagnostic but not always present; in their absence, bedside echocardiography should be done if the diagnosis is suspected.

  • Subxiphoid pericardiocentesis is a temporizing measure and may be falsely negative; a pericardial window or pericardiotomy is more definitive.

NOTE: This is the Professional Version. CONSUMERS: View Consumer Version
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