Pericardial effusion and cardiac tamponade

Pericardial effusion is the acute or chronic accumulation of fluid in the pericardial space (between the parietal and the visceral pericardium) and is often associated with a variety of underlying disorders. The fluid can be either bloody (e.g., following aortic dissection) or serous (usually idiopathic). As the pericardium is rather stiff, the capacity of the pericardial space is limited. In chronic effusion, the pericardium can stretch to a certain degree, accommodating slightly more fluid. In the acute setting, however, the added volume quickly exceeds the maximum capacity of the pericardial space. In both cases, the end result is often cardiac tamponade: compression of the heart which can lead to a life-threatening reduction in cardiac output. Pericardial effusion is initially asymptomatic, but cardiac tamponade has a distinct clinical presentation, including hypotension, tachycardia, jugular venous congestion, and pulsus paradoxus. Echocardiography is the most important diagnostic procedure and usually reveals an anechoic pericardial space. Treatment depends on hemodynamic stability: unstable patients require quick pericardial fluid drainage, through either pericardiocentesis or surgery, whereas in stable patients, treatment focuses on the underlying disease.

• Hemopericardium
  • Cardiac wall rupture (e.g., complication of myocardial infarction)
  • Chest trauma
  • Aortic dissection
  • Cardiac surgery (e.g., heart valve surgery, coronary bypass surgery)
• Serous pericardial effusion
  • Idiopathic
  • Acute pericarditis (especially viral, but also fungal, tuberculous or bacterial)
  • Malignancy
  • Poststernotomy syndrome
  • Uremic
  • Autoimmune disorders
  • Hypothyroidism

References:^[1]

Limited elasticity of the pericardium → ∼ 150–200 mL of fluid → ↑ pressure in pericardial space → compression of the heart, especially of the right ventricle due to a thinner wall → interventricular septum shifts towards the left ventricle chamber → ↓ ventricular diastolic filling → ↓ stroke volume (+ venous congestion) → ↓ cardiac output

References:^[2]

• Usually initially asymptomatic
• Shortness of breath, especially while lying down (orthopnea)
• Beck's triad
  • Hypotension
  • Muffled heart sounds
  • Distended neck veins
• Tachycardia, pulsus paradoxus
• Retrosternal chest pain
• Apical impulse difficult to locate or nonpalpable
• Pallor, cold sweats
• Symptoms of left heart failure and symptoms of right heart failure
• Cardiogenic shock, asystole

Beck's triad for cardiac tamponade: hypotension, muffled heart sounds, distended neck veins!

References:^[1][3][4][2]

• Echocardiography (gold standard)
  • Anechoic space between pericardium and epicardium
  • Reduced ejection fraction
  • Reduced wall motion
• CXR: enlarged cardiac silhouette, clear lungs, in severe cases a globular "water bottle-shaped" heart contour (water bottle sign)
• ECG
  • Low voltage
  • Electric alternans
• Pericardial fluid drainage: used to sample the effusion in cases of unclear etiology

Echocardiography is a quick and safe diagnostic tool for detecting pericardial effusions and pericardial tamponade!

References:^[1][3][4]

Hemodynamically unstable

• Pericardial fluid drainage: ultrasound-guided pericardiocentesis or surgical drainage
• Subsequent surveillance in an intensive care unit (ICU)

Acute pericardial effusion with pericardial tamponade is a life-threatening condition, requiring immediate pericardial decompression!

Hemodynamically stable

• Treatment of underlying cause
• Pericardial window: an incision in the pericardium is made that allows continual drainage; from the pericardial space into the pleural cavity to prevent a cardiac tamponade
  • Commonly indicated for effusion due to underlying malignancy
• Hemodynamic monitoring

References:^[3][4]