Question 7
Describe the possible echo findings in a patient with pericardial effusion
1. Distribution
- Circumferential
- Loculated
2. Echogenicity
- Anechoic
- Echoic depending on it’s composition (blood may be echoic, pus also)
- May be associated with fibrin strains if chronic
3. Size
- small < 1cm
- moderate 1 cm – 2 cm
- large > 2 mm
- Measurement of effusion is measured at the end of diastole
4. Pericardium may be thickened (malignancy, inflammation)
5. May be associated aortic flap in dissection
6. Haemodynamic evaluation. Tamponade is a clinical diagnosis.
- RA wall collapse – in early systole or late diastole. If more than 1/3 of the cardiac cycle then this is almost 100% specific and sensitive for clinical cardiac tamponade. If found alone then not very specific for tamponade. Best seen in subxiphoid and apical 4 chamber
- RV wall collapse – in diastole. First only in expiration then throughout the cardiac cycle. The longer the indentation of the free wall, the more significant the severity of the haemodynamic compromise. Difficult to assess when the heart is swinging
- LA collapse – usually seen with RA collapse. Not common
- LV wall collapse – unusual – seen in patients with severe pulmonary hypertension
- Swinging heart
- Septal shift towards the left ventricle during inspiration
- Increase E wave in tricuspid PW inflow of > 40% on inspiration
- Increase in mitral valve E wave PW inflow of >25% on expiration.
- Mitral inflow and Tricuspid inflow difficult to assess in AF
- IVC is fixed and dilated, unless the patient is severely dehydrated. Called “low pressure cardiac tamponade” and BP can be improved with iv fluids.
- PW Doppler reversal in hepatic veins
Note that tamponade may be present even if there are no 2D ECHO features suggestive of tamponade when there are preexisting high RV and RA pressures