Doppler signs of cardiac tamponade
Doppler signs of cardiac tamponade
Doppler signs of cardiac tamponade
Doppler Echocardiographic Signs of Cardiac Tamponade
Cardiac tamponade causes exaggerated ventricular interdependence due to pericardial constraint, which is well reflected in Doppler studies. These Doppler changes are considered the echo equivalent of pulsus paradoxus.
1. Mitral Inflow (Transmitral E-wave)
- Normal: Minimal respiratory variation (<10%).
- Tamponade:
- Inspiratory decrease >25% in peak E-wave velocity.
- Due to reduced LV filling when RV expands in inspiration.
2. Tricuspid Inflow (Transtricuspid E-wave)
- Normal: Small increase in inspiration.
- Tamponade:
- Inspiratory increase >40% in peak E-wave velocity.
- Due to augmented RV filling during inspiration.
3. Pulmonary Vein Doppler
- Tamponade:
- Decreased systolic forward flow with inspiration.
- Reflects impaired LV filling.
4. Hepatic Vein Doppler
- Tamponade:
- Expiratory diastolic flow reversal is a classic sign.
- Reflects impaired RV filling during expiration.
5. LV Outflow Tract (Aortic Flow)
- Tamponade:
- Inspiratory decrease in LV outflow velocity (>10%).
- Reflects reduced stroke volume with inspiration.
✅ Summary Table of Doppler Findings
| Doppler Site | Normal | Tamponade Change |
|---|---|---|
| Mitral inflow (E-wave) | <10% resp. variation | ↓ >25% in inspiration |
| Tricuspid inflow (E-wave) | Mild ↑ in inspiration | ↑ >40% in inspiration |
| Pulmonary vein | Normal forward flow | ↓ systolic forward flow in inspiration |
| Hepatic vein | Forward diastolic flow | Expiratory diastolic flow reversal |
| LVOT / Aortic flow | <10% variation | ↓ in inspiration (>10%) |
👉 Take-home:
On Doppler, tamponade is characterized by marked respiratory variation in mitral and tricuspid inflows, expiratory hepatic vein flow reversal, and decreased aortic flow in inspiration, all reflecting exaggerated ventricular interdependence.
1. What is the hallmark Doppler finding of tamponade?
Exaggerated respiratory variation in ventricular inflow velocities
Fixed transmitral inflow velocity
Mitral regurgitation jet
Tricuspid regurgitation jet
Tamponade produces exaggerated respiratory variation in mitral and tricuspid inflows due to ventricular interdependence.
2. In tamponade, what happens to mitral inflow E-wave during inspiration?
Decreases >25%
Increases >25%
No change
Decreases only in expiration
Mitral inflow decreases by >25% during inspiration, the Doppler correlate of pulsus paradoxus.
3. In tamponade, tricuspid inflow E-wave during inspiration:
Decreases >25%
Increases >40%
No change
Becomes biphasic
Tricuspid inflow increases by >40% with inspiration in tamponade.
4. The Doppler equivalent of pulsus paradoxus is:
Respiratory variation in mitral and tricuspid inflows
Flow reversal in coronary sinus
Continuous forward flow in hepatic vein
No variation in pulmonary venous inflow
Pulsus paradoxus correlates with exaggerated inflow variations on Doppler echo.
5. Pulmonary vein Doppler in tamponade shows:
Systolic flow reversal
Reduced systolic forward flow in inspiration
No variation with respiration
Diastolic dominance in expiration
Pulmonary venous systolic forward flow decreases in inspiration due to impaired LV filling.
6. Which Doppler site shows expiratory diastolic flow reversal in tamponade?
Pulmonary vein
Hepatic vein
Coronary sinus
LVOT
Hepatic vein Doppler shows expiratory diastolic flow reversal in tamponade.
7. In tamponade, aortic outflow Doppler shows:
Inspiratory decrease >10% in velocity
Inspiratory increase >40%
No change
Flow reversal
Inspiratory decrease in LVOT/aortic flow velocity reflects reduced LV stroke volume.
8. Normal mitral inflow variation with respiration is:
>25%
15–20%
<10%
>40%
Normal transmitral inflow shows <10% respiratory variation.
9. In tamponade, LV filling is most reduced during:
Inspiration
Expiration
Both equally
Unrelated to respiration
During inspiration, increased RV filling shifts septum and reduces LV filling.
10. RV filling in tamponade is enhanced during:
Inspiration
Expiration
No respiratory variation
Only during Valsalva
RV filling increases during inspiration in tamponade.
11. Which Doppler change is analogous to pulse oximetry evidence of pulsus paradoxus?
Mitral inflow ↓ >25% with inspiration
Continuous hepatic vein flow
Tricuspid regurgitant jet variation
No change in pulmonary vein flow
The Doppler equivalent of pulsus paradoxus is mitral inflow decrease >25% in inspiration.
12. Which Doppler parameter is most specific for tamponade?
Mitral inflow variation
Expiratory diastolic flow reversal in hepatic veins
Pulmonary venous diastolic dominance
Tricuspid regurgitation jet
Hepatic vein expiratory diastolic flow reversal is a highly specific Doppler sign of tamponade.
13. In tamponade, tricuspid inflow velocity decreases in:
Expiration
Inspiration
Both phases
No respiratory effect
Tricuspid inflow decreases in expiration and increases in inspiration due to ventricular interdependence.
14. Which Doppler flow pattern reflects impaired LV stroke volume in tamponade?
Continuous forward flow
Inspiratory fall in aortic velocity-time integral
Diastolic reversal in coronary sinus
Systolic dominance in pulmonary veins
LV stroke volume falls during inspiration, reflected in LVOT Doppler changes.
15. Pulmonary vein Doppler abnormality in tamponade primarily reflects:
Reduced LV filling
Increased RV filling
Tricuspid regurgitation
Elevated LA pressure
Pulmonary venous changes are due to reduced LV filling during inspiration.
16. The exaggerated Doppler variation in tamponade is due to:
Pericardial effusion volume
Ventricular interdependence
Conduction abnormalities
Valve stenosis
Ventricular interdependence explains Doppler variation in tamponade.
17. Hepatic vein Doppler normally shows:
Forward diastolic flow during inspiration
Diastolic reversal during expiration
No respiratory variation
Continuous reversal flow
Normally hepatic veins show forward diastolic flow; reversal in expiration suggests tamponade.
18. In tamponade, why does mitral inflow decrease in inspiration?
Increased RV filling shifts septum, reducing LV filling
Decreased pulmonary venous return
Mitral valve stenosis
Atrial fibrillation
Septal shift in inspiration limits LV filling, reducing mitral inflow.
19. Doppler hallmark differentiating tamponade from large effusion without tamponade is:
Exaggerated respiratory variation in flows
Presence of pericardial effusion
IVC dilatation
Right atrial collapse
Doppler evidence of exaggerated respiratory variation is diagnostic of tamponade physiology.
20. Which Doppler abnormality in tamponade is most closely linked with impaired RV filling?
Mitral inflow variation
Pulmonary venous variation
Expiratory hepatic vein diastolic reversal
Aortic flow variation
Hepatic vein expiratory diastolic reversal indicates impaired RV filling in tamponade.
Summary Table: Doppler Signs in Cardiac Tamponade
| Point | Doppler Finding | Key Feature / Threshold | Clinical Importance |
|---|---|---|---|
| 1 | Mitral inflow (E-wave) | Inspiratory ↓ >25% | Echo equivalent of pulsus paradoxus |
| 2 | Tricuspid inflow (E-wave) | Inspiratory ↑ >40% | Reflects RV dominance in inspiration |
| 3 | Pulmonary vein flow | Inspiratory ↓ in systolic forward flow | Impaired LV filling |
| 4 | Hepatic vein Doppler | Expiratory diastolic flow reversal | RV restriction during expiration |
| 5 | LVOT / Aortic flow | Inspiratory ↓ >10% | Reduced LV stroke volume |
| 6 | RVOT / Pulmonic flow | Expiratory ↓ >10% | Reflects interventricular dependence |
| 7 | Inspiratory variation | exaggerated (>25–40%) | Hallmark of tamponade |
| 8 | Normal transmitral variation | <10% | Helps distinguish normal from abnormal |
| 9 | Normal transtricuspid variation | <25% | Helps define cutoff |
| 10 | SVC Doppler | ↓ forward flow in expiration | Supports diagnosis |
| 11 | IVC Doppler | Blunted variation | Consistent with venous congestion |
| 12 | Mitral A-wave | Inspiratory reduction | Secondary LV filling compromise |
| 13 | Tissue Doppler (mitral annulus) | Exaggerated respiratory variation | Confirms ventricular interdependence |
| 14 | Hepatic systolic flow | Blunted or reversed | Severe tamponade |
| 15 | Doppler hallmark | Exaggerated respiratory variation | Equivalent to pulsus paradoxus |
| 16 | Severity correlation | More pronounced changes = severe tamponade | Guides urgency |
| 17 | Loculated effusion | May cause atypical Doppler patterns | Requires correlation |
| 18 | Constriction vs tamponade | Constriction → preserved expiratory hepatic flow reversal | Differentiates pathologies |
| 19 | Timing | Doppler changes occur before overt hemodynamic collapse | Early diagnosis |
| 20 | Integration | Must combine with effusion + chamber collapse | Essential for accurate diagnosis |
📘 10 Short Q&A Block: Doppler Findings in Tamponade
Q1. What is the hallmark Doppler sign of tamponade?
👉 Exaggerated respiratory variation in transvalvular flows.
Q2. What is the cutoff for inspiratory decrease in mitral inflow (E-wave)?
👉 >25%.
Q3. What is the cutoff for inspiratory increase in tricuspid inflow (E-wave)?
👉 >40%.
Q4. What pulmonary vein Doppler change is seen in tamponade?
👉 Inspiratory decrease in systolic forward flow.
Q5. What hepatic vein Doppler change is typical of tamponade?
👉 Expiratory diastolic flow reversal.
Q6. What change occurs in aortic LVOT flow during inspiration?
👉 >10% decrease in velocity.
Q7. What RVOT (pulmonic) Doppler change occurs in expiration?
👉 >10% decrease in velocity.
Q8. What is the normal transmitral inflow respiratory variation?
👉 Less than 10%.
Q9. How does tissue Doppler behave in tamponade?
👉 Shows exaggerated respiratory variation in mitral annular velocities.
Q10. How to differentiate tamponade from constrictive pericarditis on Doppler?
👉 Tamponade: inspiratory changes dominate;
👉 Constriction: expiratory hepatic flow reversal is more typical.
