Tamponade

This station covers cardiac tamponade and tamponade pathophysiology. Cardiac tamponade is a clinical diagnosis. 

A. 2D Imaging

The clip shows the presence of a large circumferential pericardial effusion. The arrow points to the RVOT. There is collpase of the RVOT in diastole.

The PSAX view shows a circumferential pericardial effusion. The LV end diastolic and end systolic volumes are small. The heart appears to be swinging in the pericardial sac.

Apical 4 Chamber view. A large cicumferential pericardial effusion is present. The heart is swinging.

IVC is plethoric and there is no respiratory variation.

  • Use all 3 cardiac windows (Parasternal, Apical and Subcostal) to image the heart.
  • Determine the size: Measure the effusion in multiple locations at end-diastole. Ensure that the view used and location where measurement is performed is recorded to allow for comparison during repeat evaluations.
  • Determine the location: Anterior, Posterior, Localised or Circumferential
  • Determine the effects of the effusion on cardiac function: Swinging heart, RV Diastolic Collapse, RA Early Systolic Collapse
  • Measure the IVC and respiratory variation in response to a sniff.

B. M-Mode Imaging

  • The M-Mode here is performed in the PLAX view. There is a pericardial effusion present and collapse of the RVOT seen during diastole (top most trace).
Image From: Echocardiographic Evaluation of Pericardial Effusion and Cardiac Tamponade. Front Pediatr 2017
  • The bottom 2D and M-Mode image shows RA collapse in end-diastole/early systole.
  • M-Mode is useful to evaluate motion of a focused cardiac structure (y-axis) against time (x-axis).

C. Doppler Evaluation

1. Mitral and Tricuspid Inflow Velocities & Respiratory Variation

  • NORMAL Respiratory Variation: Pulsed-wave Doppler Mitral and Tricuspid Inflow.
  • In spontaneously breathing healthy individuals, Doppler peak velocities in the tricuspid and pulmonary valves increase during inspiration, while they decrease in the mitral and aortic valves.
  • A physiological variation of the cardiac output of around 5% exists with normal respiratory cycle, which is reflected in normal peak E-wave variation of up to 10%
Image From: Echocardiographic Evaluation of Pericardial Effusion and Cardiac Tamponade. Front Pediatr 2017
  • TAMPONADE:
  • Increased Respiratory Variation seen in mitral and tricuspid inflow patterns
  • B: Mitral Inflow – Inspiratory Decrease > 25-30% is consistent with tamponade physiology
  • C: Tricuspid Inflow Expiratory Decrease > 60% is consistent with tamponade physiology 

2. LVOT and RVOT Velocities & Respiratory Variation

Image From: Echocardiographic Evaluation of Pericardial Effusion and Cardiac Tamponade. Front Pediatr 2017
  • During inspiration a drop of >10% of the peak velocity will be seen in the aorta, while the opposite will happen in the right ventricular outflow tract, where an increase of at least 10% will be noticed
  • Image shows respiratory variability seen with Doppler analysis of the left ventricular outflow tract, demonstrating decrease of >10% following deep inspiration.