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Posts Tagged ‘ero’

The short answer is, Yes.

Detailed answer is also yes : Read further please.

The MitraClip procedure, is designed to reduce mitral regurgitation (MR) by approximating the mitral valve leaflets, can alter the direction or nature of residual MR, including potentially converting a central MR jet into an eccentric one . This possiblity depends on the pre-procedural anatomy, the placement of the clips, and the resulting changes in mitral valve dynamics.

Central MR in ischemic dilated cardiomyopathy (DCM) typically arises from functional MR, where symmetric annular dilation and leaflet tethering (due to LV remodeling) create a central regurgitant jet through a malcoapted valve. The MitraClip works by grasping the anterior and posterior leaflets, usually at the A2-P2 segments, to create a double-orifice valve, reducing the regurgitant orifice area. When successful, this diminishes the overall MR volume, often preserving the jet’s central nature if residual MR remains.

However, if the clip placement is asymmetri or if multiple clips are positioned unevenly, the geometry of the mitral valve can shift. This could redirect the residual regurgitant flow. For example, if the clip is placed more toward the medial or lateral commissure, or if it disproportionately restricts one leaflet’s motion (e.g., excessive tethering of the posterior leaflet), the remaining gap might produce an eccentric jet directed toward the opposite side of the left atrium.

Echocardiographic studies post-MitraClip occasionally report changes in jet direction. While the primary goal is MR reduction, not all procedures eliminate regurgitation entirely, and residual MR jets can appear eccentric depending on how the leaflets coapt after clipping. For instance, if the clip reduces central coaptation but leaves a smaller, off-center orifice, the jet might angle toward the atrial wall, resembling eccentric MR seen in organic valve disease (e.g., prolapse). This isn’t necessarily a conversion from central to eccentric in the classical sense but rather a modification of the residual flow pattern.

Clinical data doesn’t frequently highlight this as a major issue. In trials like COAPT and MITRA-FR, the focus is on MR severity reduction rather than jet direction, and eccentric jets aren’t systematically reported as a post-procedural phenomenon. However, case studies and operator experiences suggest that jet redirection can occur, particularly with suboptimal clip positioning or in complex anatomies.

Implication of new onset eccentric jet

1.Eccentric jet directed towards one of the pulmonary veins can cause unpredictable postural dyspnea.

2.Eccentric jets are difficult to quantify the exact post clip ERV.

3.Can Interfere with favorable remodelling of LA

4.Might Increase IE risk

Final message

Mitra-clip is an innovative catheter-based MR jet interrupter. However, it is not surprising this device could convert a central MR into an eccentric MR, considering the fact that it tampers with mitral valve orifice morphology almost blindly. Adding more complexity is that, the clip brings one more “Neo-regurgitation orifice”. Mitra-clip still can be useful in very selected patients, where it regresses the MR significantly. But, experience tells us the importance of precise clip deployment guided by meticulous imaging and expertise.

Postamble and a follow up question

Can mitraclip convert an eccentric jet into a central one ?

It would be great if this is possible .The problem here is , it need too much precision and overcoming the uncertainity of the iatogenic second jet morphology.

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Echocardiography is about 50 years old tool.It has evolved from simple M mode to sophisticated tissue Doppler and 4D imaging. Color Doppler imaging was a great revolution ( One  can  consider it  as big as invention of ultrasound itself  !)

Even though , we could code the pulse Doppler samples into color coded pixels (Called auto correlation computed by Fourier algorithm) the full potential of color Doppler is yet to be explored. Accurate assessment of regurgitation  lesion severity continue to trouble  us  .

The PISA concept fizzled out due it’s complexity and   inaccuracy.It  exhausted  thousands of  cardiology man  hours  and  precious  academic time ! (Not really waste . . .it stimulated our intellect !)

I wonder we have a method to predict  early  “The would be failed concepts”  in medicine !

Vena contracta* Who named it     http://en.wikipedia.org/wiki/Vena_contracta

Suddenly common sense struck us . . .  simplicity replaced complexity . The concept of vena contracta came in to vogue.

It is a  simple estimate of the  narrowest part of a regurgitant  jet.It  is good enough to assess the severity of regurgitation .The diameter is measured  in the   zoomed up view of  the  leaky valve  aided by color flow. If it is > 6mm it is severe regurgitation .(Both AR/MR)

Please note ,it is  one of the measurement  we  take in the  dimensional regurgitant  shell of (blood dome )  in the PISA method . The harrowing exercise of calculating ERO  with all those radius and velocity etc  may be fresh in many  minds !

Can’t we extend the simplicity of  the concept of vena contracta further ?

As usual ,  we assume  many things in medicine .

Here the concept of Vena contracta(VC)  requires

  • The orifice is near circular. (Very unlikely , considering the complex shape of mitral valve especially in diseased state)
  • The vena contracta applies only to single jet MR
  • Central jet (Eccenticity increase the chances altering the shape of ERO )

but, the major advantage is VC is not much  influenced by loading conditions .And the parameter used as such without amplifying the error.

Why vena contracta  is not used to  assess mitral stenosis  severity ?

I wonder why it shoudn’t ?  The same principles apply, the flow through  narrowest point of mitral  valve  will reflect the degree  of narrowing. In fact ,the inter-leaflet distance  could be   same as  vena contracta  in mitral stenosis.

If we assume !   the orifice as a circle,  then  50 %  the vena contracta is   the radius  the orifice  and ERO  can be easily arrived .

Logically yes. We need to validate the data ,comparing with a gold standard .When there is no gold standard , and what  we are testing is  better than gold standard what shall we do ?

Final message

Complex  measurements  lead to  complex errors (Lesson learnt from PISA) , with simple parameters  errors do not get amplified.

Do not ditch any investigation just because it is simple  . . .

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