Cardiac Tamponade on Echocardiography: Chamber Collapse and Respiratory Variation of Transvalvular Flows
Key Echocardiographic Signs of Tamponade
According to the recommendations for echocardiographic assessment of rheumatic heart disease (ASE, 2023; Pandian N.G. et al., 2023), echocardiographic signs of cardiac tamponade include three groups of findings.
| Sign | Characteristic |
|---|---|
| Early diastolic collapse of the RV free wall | Best visualized in M-mode over the RV wall; sensitivity is reduced in RV hypertrophy and pulmonary hypertension (PH) |
| Signs of increased ventricular interdependence | Respiratory discordance of flow velocities through the MV and TV; changes in ventricular internal dimensions with respiration; interventricular septal 'bounce' |
| Dilated IVC | Reduced respiratory response (decreased collapse on inspiration) |
Chamber Collapse
Early diastolic collapse of the right ventricle free wall is best assessed in M-mode over the RV wall. It is important to note that the sensitivity of this sign is reduced in the presence of right ventricular hypertrophy and pulmonary hypertension (ASE, 2023). Right atrial (RA) collapse is a sensitive but not specific sign of cardiac tamponade.
Respiratory Variation of Transvalvular Flows
Increased ventricular interdependence is manifested by respiratory discordance of filling flow velocities through the mitral and tricuspid valves, changes in ventricular internal dimensions depending on the phase of respiration, and interventricular septal 'bounce' (ASE, 2023). Physiologically, the right atrium fills with blood during inspiration because at this phase the pressure in it is lower than in the veins (Blagodir B.V., 2024).
IVC Assessment
A dilated inferior vena cava with reduced respiratory response reflects increased systemic venous pressure and is part of the complex of signs of tamponade (ASE, 2023).
Frequently asked questions
Which mode is optimal for detecting RV wall collapse?
Early diastolic collapse of the RV free wall is best visualized in M-mode over the RV wall (ASE, 2023).
In which cases is the sensitivity of the RV collapse sign reduced?
Sensitivity is reduced in the presence of right ventricular hypertrophy and pulmonary hypertension (PH) (ASE, 2023).
How specific is right atrial collapse?
RA collapse is sensitive but not specific for cardiac tamponade (ASE, 2023).
How is increased ventricular interdependence manifested?
By respiratory discordance of flow velocities through the MV and TV, changes in ventricular internal dimensions with respiration, and interventricular septal 'bounce' (ASE, 2023).
What happens to the IVC in tamponade?
The IVC is dilated with reduced respiratory response (ASE, 2023).