🔑 Key Learning

  • Cardiac tamponade occurs when fluid builds up in the pericardial space, leading to diastolic compression of the heart and reduced cardiac output
  • Presents with shortness of breath, tachycardia, and Beck’s triad: hypotension, raised JVP, muffled heart sounds
  • ECG may show electrical alternans
  • Treatment is urgent pericardiocentesis

🧬 Pathology

  • Cardiac tamponade is caused by accumulation of fluid within the pericardial sac.
  • As intrapericardial pressure rises above diastolic pressures, ventricular filling becomes impaired, resulting in reduced stroke volume and cardiac output.
  • Common causes include trauma, myocardial infarction, malignancy, and post-cardiac surgery.
Figure 190: Graphic of cardiac tamponade. BruceBlaus.Blausen 0164 Cardiac Tamponade 02. CC BY 3.0

         

🩺 Clinical Features

  • Symptoms: Shortness of breath
  • Beck’s Triad:
    • Hypotension
    • Muffled heart sounds
    • Raised JVP
  • Additional findings:
    • Pulsus paradoxus (drop in systolic BP >10 mmHg on inspiration)
    • JVP with absent Y descent due to restricted right ventricular filling

🔬 Investigations

ECG may show:

  • Electrical alternans – alternating QRS amplitude beat-to-beat, due to swinging heart within the fluid-filled pericardium

💊 Management

  • Urgent pericardiocentesis is required to relieve the pressure and restore cardiac output

📷 ECG Interpretation Practice

📝 Try to interpret the following ECG:

  • What pattern do you see in the QRS complexes?
Figure 191: ECG demonstrating electrical alterans in Pericardial effusion with tamponade. Jer5150. CC BY-SA 3.0.