Friday, May 13, 2016

Tips on echocardiography for constrictive pericarditis

  •  Echocardiographic features of constrictive pericarditis include:
               - Septal bounce
               - dilated IVC
               - dilated hepatic veins with diastolic flow reversal on expiration
               - absence of normal sliding motion between the RV and the liver
               - respiratory varitions of mitral E velocity with more than 25% increase with expiration 
  • Respiratory variations of mitral inflow (E-wave) is not always present in constrictive pericarditis. It can be masked by increased left ventricular end diastolic pressure. However, it can be unmasked by imaging in the sitting up position. Also some diuretics may unmask it. Howeverm its absence does not exclude constriction.
  •  Respiratory variations of mitral E-wave velocity can occur also with COPD. in cases of COPD, the highest E-wave is at onset of expiration, while in constriction, the highest E-wave is at end expiration. Another useful tip, use SVC flow to differentiate COPD from constriction. In COPD SVC systolic flow increases markedly with inspiration. But in case of constriction, SVC diastolic flow shows limited increase with inspiration (less than 20cm/sec).
  • Using Tissue Doppler Imaging to differentiate constriction from restriction:
               - medial mitral e' velocity less than 8 cm/sec is associated with restriction.
               - constriction is associated with "Annulus Reversus" on TDI. This means that the medial annular e' velocity is higher than that of lateral annulus. Normally, the lateral mitral annular e' velocity is higher than the medial by more than 20%. This annulus reversus disappears after pericardiectomy.