Hamman's sign

Precordial crunching or crackling sound, typically systolic and synchronous with the heartbeat, produced by the heart moving against air-filled mediastinal or pleural tissues, indicating the presence of air in abnormal thoracic compartments.

Causes

• Air leakage into the mediastinum

  • Spontaneous pneumomediastinum

  • Esophageal rupture (Boerhaave's syndrome)

  • Air leakage after bronchoscopy or endoscopy

• Pleural causes

  • Left-sided pneumothorax

  • Pneumopericardium

  • Pleural air adjacent to the heart

• Pulmonary causes

  • Lung rupture due to barotrauma

  • Mechanical ventilation-related injury

  • Severe asthma attacks

  • COPD exacerbations

• Iatrogenic causes

  • Invasive airway procedures

  • Endoscopic procedures

  • Thoracic surgery or interventions