Feeds:
Posts
Comments

Posts Tagged ‘narrow qrs vt’

How to name  a ventricular tachycardia ?

This  continues to be a  favorite past & present  time of  modern-day cardiologists. Especially ,  VTs associated with structurally normal heart  suffers with this  protracted problem .Widespread use of  EP study has not solved the issue as yet.

The   VTs that arise from the left ventricle in an apparently normal heart   has been referred  by  various terms.

  • VT with structurally  normal heart
  • Idiopathic left ventricular tachycardia
  • Verapamil sensitive  VT
  • Septal VT (It can be either myocardial /non myocardial origin)
  • Narrow qrs VT
  • Fasicular VT
  • LVOT tachycardia
  • Hemodynamically stable VT
  • Belhassen VT

Now we have still more exotic VTs like Cuspal , mitral annular , etc . All of the above can mean anything , or same thing   in different centers  ,  different cardiologists in different times .

* RVOT tachycardias also have  many synonyms.( Adenosine sensitive, Adrenergic,  Gallavardin, Parkinson Pop, etc )

VTs associated with CAD , valvular , myocardial diseases generally devoid of  nomenclature problems. Ischemic VT  is yet to be classified in a proper fashion.

The confusion in classifying VT is  not due to the complexity of heart disease. It is due to  the general  comprehension failure as  every VT can be described with reference to clinical , ECG morphology, hemodynamics and presence or absence of underlying heart disease. A simplified and clinically useful VT classification is being prepared in this forum .Will be published shortly .

Read Full Post »

Traditionally we believed VT can originate only  from the ventricular myocardial cells . Then we realised many of the VTs shared the characteristics of SVT. When these were analysed , it was found VTs , after all ,   do not have   a big deal of   difference wth SVT s ! especially when it arises from the high septum .Contary to the conventional teaching  the AV node is not a anatomically distinct and discrete  structure  .Instead it is made up of  thousands of specialised cells located in AV junctional area .These cells ramify both superiorly and inferiorly like an octopus . Hence  , it does not require great academics to understand AV Nodal properties extend downward into the IVS for some distance . In some individuals   clusters of cells with  slow conducting  property (Which is a hall mark of AV nodal tissue )  may invade deep into the IVS .The interface of  these slow conducting tissue with that of  fast septal purkinje fibres , make it a  perfect platform for  the potential slow-fast reentry within IVS. This forms the basis of fascicular  VT.

Clinical features

  • Since it shares the  properties of SVT , the natural history is also relatively beningn
  • Occurs in young
  • Hemodynamically stable ( More physiological conduction : Superi inferior Like SVT)
  • Narrow qrs (Narrow because the VTdoes not travel by cell to cell instead  run through the normal conduting system for most part in the circuit)
  • Verapamil sensitive .(Mimic AV nodal Tach)
  • Degeneration into VF is  rare  and hence  SCD is not a big  issue
  • Tachycardic myopathy can occur.

fascicular vt ventricular tachycardia  ecg  svt avnrt avrt wpw

Note:

Fascicular tachycardia is also known in several names.

It forms the bulk of the causes for  idiopathic left ventricular VTs .Other being LVOT VT.

Described first by Cohen in 1974 , followed by Zipes , when they noticed  it was possible to reproduce atrial induction of VT.

Belhassen in 1984 found the verapamil sensitivity of this VT

Other synonyms some times used are

  • Septal VT
  • Narrrow qrs VT

Download high resolution table

Fascicular tachycardia

Read Full Post »