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Archive for the ‘PTMC’ Category

Significant MR is a contraindication for PTMC. However,  If MR jet is central , and mild (some times little more than mild as well ) PTMC can be safely done. The MR may not worsen .It may even disappear.

Note: Eccentric MR jets are indirect evidence for sub valvular disease. Its very likely to get worsened and may require a mitral valve replacement .

Here is patient with severe mitral stenosis, the MR is in all probability safe.

Angle of eccentricity 

One must realise , the eccentricity of a jet is not very objective .What may appear as central jet in long axis may be wall hugging in 4 chamber view. This is very important to recognise. Further , even central jets can reveal a invisible eccentricity detected only on 3D MR jet reconstruction.

One simple way to ascertain central jet is to  check whether the MR jet align in the same angle as diastolic color jets of MS into LV inflow . (Looking carefully ,the diastolic color jets also provide us info about sub-valvular disease )

More anatomical distortion in this patient 

Incidentally , this patient also had another anatomical adversary  ie ,the bulge of IAS into right atrium. This can happen two ways .Septal aneurysm or a normal septum bulging to RA due to raised mean LA pressure.

 

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Miral stenosis with Atrial fibrillation showing the changing mitral inflow jet .

 

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The radius of curvature of IAS bulge Indicates its more of septal weakness that contributes than the raised pressure. There is a small risk in these patients the IAS flap may give way during the procedure and a small ASD may be created .(Hemodynamically may not be significant though)

 

How does the MR disappear after balloon dilatation ?

If you ask this question , it means your are a thinking cardiology fellow , good.

Guess your answer. Its all about physics of  MVOs behavior  in systole and diastole . The mitral valve tissue attachment and adhesion causes not only a  diastolic narrowing but also a fixed systolic regurgitant orifice.Once you relive it the leaflets begins to co-opt normally without a systolic leaky orifice.

Final message

Though there are clear contraindications ,suitability of mitral valve for PTMC is more of a personal experience and confidence. A MR jet of grade 1  may be acceptable. A huge LA, Distorted IAS anatomy, a clot confined to LA appendage are relative contraindication only. The puncture site on IAS , minimal manipulation guide wire within LA, a gentle over the wire technique to cross mitral valve or some of the tips for success.

Never hesitate however to refer complex cases of mitral stenosis to the surgeons. Of course , you can’t insist them to do a valve preserving OMV .It is unfortunate(They have good point of argument as well)  most of the surgeons have have made Mitral valve replacement as a default modality

Post ample :

When we were cardiology fellows , we used to have a mitral valve scoring system for suitability for PTMC. Its called Wilkin’s score. Its a purely an anatomical score. (I guess still its expected in Board exams) What we need is comprehensive anatomical and physiological assessment of mitral valve. With due respects to  published literature this scoring system lacks  two  vital parameters we look before PTMC , namely the extent of commissural calcium  and degree of MR.

 

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PTMC involves a critical step , where one has to cross  the IAS to reach the LA.The septal puncture remains  somewhat a blind procedure in fluoroscopy .(Echo can still assist us. )

Stitch effect is a rare complication where the needle pierces the intrapericardial space from the right atrial side and re-enter the left atria .This wrong way entry into LA may not be recognised  untill the sheath is withdrawn and a cardiac tamponade ensues after removal.

Where exactly the stitch  occurs ? What are  the anatomical planes ?

This usually  happens in the superior aspects of   IAS , abutting the roof of RA and LA . The alignment of IAS with reference to RA and LA is key a determinant.We know in mitral stenosis LA can outgrow the RA , bringing   superior aspect of LA  in a different  plane with reference to IAS  .The IAS puncture site may overshoot , enter the pericardial  space and  stitches the non IAS aspect of RA and LA together , of course  still guiding us  into LA through a false pericardial track (Which is not recognized )

stitch effect ptmc stich phenemenon

Note : The intra-pericardial track can be more complex than we realise as a significant part of posterior LA is extra-pericardial and transverse sinus of pericardium can get involved as well.

 

Our understanding(mis ?)  suggests at least four different stitches are possible

  1. IAS-Pericardial space -LA roof
  2. RA-Pericardial space -LA roof

Other complex tracts (Based on theoretical assumptions . Please note , in  some of the fatal punctures the exact  route was not identified by surgeons even under direct  vision . )

3.RA-Pericardial  space -Extra cardiac-Reenter LA

4.RA-IAS -Pericardial space-Extracardiac -Reenter LA  ?

What are the possible bleeding sites in stitch effect ?

There can be two sites of active bleeding .One from RA exit point and other from LA entry point of needle.Extra-cardiac oozing can also occur if the needle has pierced the outer pericardium before entering LA.

Management

  • Recognition is the key. It requires extra anatomic acumen to diagnose the false track before we insert and withdraw the sheath.Echocardiography should be liberally  used if you suspect a false track .
  • Tamponade  is to be  drained promptly and emergency surgery is usually required if re-accumulation occurs.
  • Closing the puncture site with devices has been successfully  attempted in few patients .A small ASD device (or a Plug ? ) is expected to close  the site of  puncture . Since the anatomy  can be complex ,one may need to  close with two devices , one on LA side and other one RA side .The radial force that closes the tear and long term retention of these device are not known .

Related topic

Other mechanisms of cardiac  tamponade during  PTMC

 

 

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