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Posts Tagged ‘tad 2cm’

Throughout the  history  of  echocardiography Right ventricular functional assessment  has received  less attention and suffered a  step motherly concern. There are innumerable parameters to assess LV function  , but we have  very few for RV !

LV ejection fraction continue  to reign supreme  in spite of the inaccuracies  and fallacies.RV ejection fraction by echo ,  never got into the main stream   cardiology literature as a tool for  RV function  assessment.

(The major reason for this  is ,  lack of  a “mathematical shape” for RV !)

RV is  formed by , a  horizontal inflow , an elongated and  wedged apex ,( in)conspicuous  body and an  ubiquitous RV outflow .No one  really knows , how  much  these  parts contribute  individually to the conductive  and contractile function of the low pressure venous ventricle.

(Of course, MRI and radionuclide derived RV EF can be accurate but doing these tests solely to measure  RV EF defies clinical sense !)

In this scenario,

Two parameter can be considered simple and accurate to estimate the RV function.

Tricuspid annular displacement (TAD)


This is a simple m-mode derived  parameter ( much ridiculed by  modern  day echo-cardiographer !)

M-mode echo in apical  4  chamber   view across lateral tricuspid annulus .

  • Normal displacement  >2 cm
  • RV dysfunction < 1.5cm
  • Borderline  RVD between    1.5 to 1.75 cm

The other parameter to measure tricuspid  motion is

Tricuspid Annulus peak Systolic velocity (TAPSV)*

  • This , in-fact linearly correlate with TAD.
  • Normal TAPSV is > 10cm/sec
  • Anything less than 8cm/sec is usually associated with RV dysfunction.

TAPSV – http://onlinelibrary.wiley.com/doi/10.1111/j.1540-8175.2006.00305.x/abstract

* One need not be  depressed if  tissue Doppler  is not availablein their  echo machine  , TVD by M mode is good enough in most situations.

Situations where RV function is impaired include

  • Severe forms of  dilated cardiomyopathy.
  • Primary (or secondary ) pulmonary hypertension
  • RV infarction
  • COPD -terminal stages
  • ARVD
  • RV dysfunction with VVI pacing
  • Following CRT

Final message

It is often  said there will  always be a simple solution for any  complex problem .  But,  it is  recognised late.

In our quest for ideal RV functional  parameter , we were entangled in the complexities for decades ,  only to realise  an obscure  M -mode  parameter in apical 4 chamber ,  could be   an  accurate way to exclude significant RV dysfunction.

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