Archive for December, 2016

Medina classification  is the most popular angiographic classification  of bifurcation lesions based on the presence or absence lesions at the three levels  of branching  (0,0,0 ) to (1,1,1). The popularity of this scheme is essentially due to its simplicity.

It can further be subdivided according to angle and size .Though there are three angles possible it is the angle of LM with LCX that matters most.

T shaped  left main. Angle of LM-LCX is around 90 Degrees

Y shaped left main. Angle of LM- LCX is > 120 Degrees

Three types of Y according to size of branch vessel size.

Y1 Large left main divided two equal LAD, LCX.

Y2 Left main and one of its branches are equal

Y3 All three are equal diameter.

Here is a series of  lectures on left main (Probably the best I guess  !)  from Dr.Boris Varshisky ,Hadassah University hospital  Jeruselam.He critically discusses about the   nuances of left main disease from pathology, technical and therapeutic considerations.

Spend some time on these videos , you should be able to learn about

  • Distribution of left main disease
  • The complexities in defining the true shapes of of left main ostia .(Ostial sharing between LCX and LAD ?)
  • Lesion based strategy
  • Carinal shift vs plaque shift
  • Stent sizing in Y 3 left main

and much , much  more !

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We know,  classical Atrial flutter (Also referred to as typical /Common AF) records  saw toothed F waves  due to continuous atrial electrical activity across a macro- reentrant circuit within right atrium.

Though this  saw tooth pattern is easily recognised , it’s often difficult to say  whether the saw is facing upwards or downwards ?

ie  Is the flutter waves are inverted or upright ?

The general rule is the shallow stroke (one with a lesser slope) is to be termed  as antegrade  / initial deflection that will determine the direction of flutter waves.


This is because , the forward limb traverses the slow path  of the circuit namely the cavo-tricuspid Isthmus, it then ascends up in the inter atrial septum (There by inscribing inverted F  waves  in leads  2,3,aVF .The return circuit  is relatively fast,  crossing the antero -lateral   free wall  right atrium and hence the later half saw tooth has a  sharp deflection )

In Reverse typical flutter  the flutter waves are upright (with a shallow slope ) in inferior leads but still uses the cavo- tricuspid Isthmus

* Note: In lead the polarity of F waves in V1 it will be opposite of that of inferior leads.


Why should we bother about direction of flutter waves  ?

It may not be important for those hifi EP guys who can ablate complex arrhythmia with intra cardiac GPS catheters and accurate electro anatomic mapping system. Still , the  surface ECG always help us understand the basic circuits of flutter.



Reverse typical flutter should not be confused with atypical flutter where typical saw tooth waves are uncommon.The later group is termed as atypical atrial flutter that arises from various other focus including left atrium.

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