Posts Tagged ‘septal rvot pacing and rbbb in ecg’

We expect LBBB in RV pacing . . .but if RBBB is recorded we are worried ! (Often times it may be neither  LBBB nor RBBB )

Is it really a panic situation ?

  • Not necessarily. The only issue is septal perforation .It is rare , can be recognised by echo or fluro .
  • In true RV apical pacing with tined leads , RBBB  is extremely uncommon .
  • If the lead  is fixed  in the septum and para hisian  area ,  there is  definite  possibility of  deviation from typical LBBB pattern . Screwing leads  that faces high septum  or outflow , RBBB  can be noted occasionally.
  • The commonest cause for RBBB pattern in RV pacing ,  is due to  screw tip going deeper into septal planes  and activating the fibers of left bundle early .
  • For LBBB pattern to occur right  bundle should be morphologically intact .In diffuse CHB  with bilateral bundle branch blocks  the relative contribution ( Impulse conduction ) will determine the QRS morphology . If right bundle is more damaged than left bundle ,RBBB pattern  may prevail  even in the midst of RV pacing !
  • In elderly men with sigmoid septum typical LBBBs are not observed.
  • Anther plausible mechanism would be , even though RV is paced , the pacemaker current’s  exit route may be from LV side .
  • Finally , always  think about coronary  sinus pacing .It is extremely common in blind temporary pacing.

What should we do if we encounter RBBB morphology after PPM ?

  • Analyse the ECG meticulosuly for capture or sensing failure .
  • Do an echocardiography in RV inflow view.
  • Screen the lead by fluroscopy
  • Check the pacing  parameters.
  • Do a holter if  you are really anxious .

If everything is fine , just forget the RBBB.Don’t split your hair for this apparent paradox. In medicine  impossibilities will always  galore !

This paper from Taiwan would vouch for this

RBBB during RV pacing safe ecg

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