Penetrating cardiac injury

Background

• Ventricles are at greatest risk due to anterior location
  • RV (involved in 40% of injuries)
  • LV (involved in 35% of injuries)
  • RA (involved in 20% of injuries)
  • LA (involved in 5% of injuries)

Clinical Features

• Stab wounds
  • Usually affect heart if enter via the "cardiac box"
    • Chest area bounded by sternal notch, xiphoid, and nipple
• Gun shot wound can affect heart even if enters at distant site

Differential Diagnosis

Thoracic Trauma

• Airway/Pulmonary
  • Bronchial injury
  • Diaphragmatic trauma
  • Hemothorax
  • Pneumomediastinum
  • Pulmonary contusion
  • Tracheal injury
  • Trachobronchial injury
  • Traumatic pneumothorax
    • Tension pneumothorax
• Cardiac/Vascular
  • Cardiac injury
    • Blunt cardiac injury
      • Cardiac contusion
      • Commotio cordis
    • Penetrating cardiac injury
    • Cardiac tamponade
  • Traumatic aortic transection
• Musculoskeletal
  • Clavicle fracture
    • Clavicle fracture (peds)
  • Rib fracture
    • Flail chest
  • Scapular fracture
  • Scapulothoracic dissociation
  • Sternoclavicular dislocation
  • Sternum fracture
  • Thoracic and lumbar fractures and dislocations
• Other
  • Esophageal injury or Perforation
  • Pneumomediastinum
  • Pneumopericardium
  • Traumatic asphyxia

Evaluation

Workup

Pericardial fluid on ultrasound

Transthoracic echo of pericardial fluid showing "swinging heart"

• FAST exam
  • First view of FAST in penetrating injury should be pericardial
  • Pericardial fluid detection (Sn 100%, Sp 97%)
    • In acute cases, even a relatively small build up of pericardial fluid can lead to hemodynamic compromise
    • Differentiate pericardial effusion from pleural effusion using the parasternal long axis view. Pericardial effusions will have an anechoic stripe between the left atrium and descending thoracic aorta. In a pleural effusion, the stripe will be seen behind the descending thoracic aorta.
• CTA
  • Imaging study of choice for penetrating and blunt trauma

Management

• Thoracotomy vs. pericardiocentesis

Cardiac tamponade

• Most often results from stab wounds; up to 80% of myocardial stab wounds may develop cardiac tamponade
• GSW less likely to develop into tamponade because it is more difficult for the pericardium to seal the defect (larger, more irregular in shape)

Cardiac missiles

• Those that cause BP instability, free or partially exposed should be removed
• Most intramyocardial and intrapericadrial bullets can be left in place

Disposition

• Admit

See Also

• Thoracic Trauma
• Blunt cardiac injury