Feeds:
Posts
Comments

Posts Tagged ‘acute rheumatic fever’

The pericarditis  of acute rheumatic fever is not a true infective pericarditis.It is more of inflammation .It is primarily  T cell mediated  reaction . Neutrophils rarely take part  in this inflammation and hence  no significant  exudation . Hence , there is less  sticky and adhesive molecules inside the pericardial space .The most inflamed layer is epicardium which a nothing but visceral  pericardium .This layer lacks the tensile strength to constrict the underlying myocardium.

why rheumatic pericarditis does not go for constrictionFor constriction to occur the fibrinous  ( thick ) layer of pericardium need to be involved . In rheumatic fever  even though it is  pancarditis ,  fibrous layer is not  involved. Further the inflammatory gradient is thought to spread from within  (Unlike tuberculosis )

Note :  In chronic tuberculous pericarditis,  diffuse inflammatory process  invade from the exterior surface . Very often ,  one can not differentiate  layers. In extreme cases even myocardium and pericardium can not be separated .

Summary

The peri-cardial effusion of acute rheumatic fever

  1. Is transient ,non infective and resolving (Unlike valvular inflammation !)
  2. Less of neutrophil activation  (Less adhesion)
  3. It does not involve the thick , tensile  fibrous layer of pericardium hence lacks the contractile force .

Other lingering  questions

1.How common is tamponade  in acute rheumatic fever ?

2.How important is the mass of the effusion (Viz  a Viz  Intra pericardial pressure !) in causing tamponade ?

//

Read Full Post »

The answer is  simple . There is no  primary rheumatic myocardial dysfunction .The  LV dysfunction is related to the valvular lesion especially  mitral regurgitation. While this is 100 % true in chronic RHD , surprisingly  it holds good even in acute rheumatic fever as well  .(I have been thinking acute myocarditis is responsible for most cases of cardiac failure in Acute rheumatic fever !)
It is a paradox  to note  myocardits  being   a major  component in acute rheumatic fever (ARF) ,  still it does not persist  long term .It invariably resolves and the injury to the  valves goes on to result in progressive valve damage .
It is heartening to note this phenomenon in ARF  ,  as myocardial involvement behaves  just like joint involvement
Shall we modify  the famous statement  of the canadian Pathologist  William Boyd  Rheumatic fever licks  the joint but bites the heart”
Though ARF  bites the heart  , it  relishes only the valve  tissue and bites it harder ,  while  it simply  licks the myocardium   like the  joints
Is there a chronic indolent myocarditis ?
It was Initially thought there could be process of chronic myocardial inflammation.But now it is almost proven there is no entity like that .
But , it is not uncommon some patients with RHD present with significant LV dysfunction which in all probability unrelated to rheumatic activity .
Assignment for cardiology fellows .
1.Where in the heart  Ascoff bodies  are densely found ?
  1. Mainly over the valve leaflets
  2. Atrial muscle
  3. Ventricular myocardium
  4. Pericardium
2.Does Ascoff  bodies disappear  in  Chronic RHD ?
Reference

Read Full Post »

Rheumatic valvulits , Valvular inflammation and edema  is the traditional answer .A detailed Echocardiographic study from All India Institute of medical sciences New Delhi  ,India  which was published in circulation 1996 answers this question most authentically .

From a meticulous  Echocardiographic  study of about 70 patients  (with both first and recurrent episodes of carditis ) the following findings were observed.

After reading this article one should be able to answer variety of  questions in RHD  such as

  • How common is MVPS in RHD ?
  • How often MR dissapear with Aspirin etc ?
  • Echocardiographic correlates  for care -coombs murmur ?

Reference

http://circ.ahajournals.org/content/94/1/73/T5.expansion.html

Read Full Post »

Acute rheumatic fever classically involves large   joints of lower or upper limbs  referred to as  fleeting migratory polyarthritis .But this pattern is  not  exclusive.  In fact   acute rheumatic  fever commonly  present with atypical features .The incidence can be up to 25 % in various series .The most surprising thing is ,  it can involve spinal as well as hip joints . Mono arthritis is also possible.

The only contention is , atypical features are  frequently  labelled by  some  as post streptococal reactive arthritis instead of rheumatic fever .

It is  pure  semantics at play . Whether you agree with the terminology or not  ,  never hesitate to diagnose rheumatic fever when the  joint involvement is  atypical . If  you ignore this  you are bound to  be guilty  for damaging few hearts  later.

What are the unusual joint involvement in acute rheumatic fever  ?

  • Small joints of the feet
  • Small joints of the hands
  • Cervical spine
  • Wrist
  • Elbow
  • Shoulder
  • Hip
  • Thoracic  spine
  • Calcaneus
  • Lumbar spine

The involvement of above joint can be up  to 25%

Here is an excellent paper from Brazil about the huge variation in the pattern of joint involvement in acute rheumatic fever.

http://www.jped.com.br/conteudo/00-76-01-49/ing.pdf

Read Full Post »

Mitral regurgitation is  one of  the most common lesion of rheumatic heart disease .Mechanism of MR in acute rheumatic fever is different from chronic rheumatic heart disease.

Acute Rheumatic fever

The following mechanisms contribute to MR of acute rheumatic fever

  1. Edema of leaflets (Carey Coombs murmur )
  2. Valvulitis
  3. Small verrucous  vegetations (See Image )
  4. Acute LV dilatation in fulminant cardiac failure.

* Note  : Acute rheumatic fever in its first episode can never  cause stenosis  however fulminant the fever may be  .There is no acute mitral stenosis .But ,  during recurrence and reactivation some amount of stenotic process may occur.  Still ,  recurrence and reactivation are more often related to significant MR rather than MS. ( Isolated mitral stenotic lesions  rarely  give h/o recurrent rheumatic fever )

Chronic rheumatic  heart disease

As the mitral valve gets progressively damaged  any combination of MS or MR occur .The following mechanism are involved in  the genesis of MR. (Pathology of Mitral stenosis is not discussed here)

  1. Chordal shortening, tethering , pulling , prevent proper co-optation
  2. Chordal lengthening
  3. Chordal disruption (Minor > Major )
  4. Prolapse of either AML or PML (Not both ,unlike myxamatous MVPS)
  5. Infective endocardits  of  leaflet
  6. Perforations of  leaflet
  7. Annular  dilatation
  8. Fibrosis of posteromedial/Antero-lateral   pap muscle(Rare )
  9. Left atrial pathology

* The direction and the  width of MR jet is  related to the mechanism of MR.

If there is chordal shortening due to fibrosis  of mitral valve  co -optation plane is altered . The degree of chordal shortening , pap muscle fibrosis (rare)  symmetry of chordal involvement determine the MR.

Rheumatic mitral valve prolapse

  • This could be  more common than we realise.
  • It can be true or pseudo.
  • True prolapse occur due to chordal weakening or lengthening .
  • In chordal disruption the leaflet tips usually become flail

Since rheumatic process fixes the PML first , the AML   appear to overshoot the plane of PML and   appear as prolapse.(Pseudo )

The sail like AML commonly  directs the jet posteriorly and laterally .(Murmur conducted to axilla and back )

It is rare for PML to prolapse in RHD , if  it does occur ,  it directs the jet anteriorly (murmur conducted to aortic area mimic AS !)

It is rare to see a  perfect  central jet in RHD  . presence of  Central jet is a good sign to consider mitral valve repair.

Myocardial involvement in RHD.

Even though rheumatic fever is a classical  example for  pan-carditis , it is surprising   to note (Of course fortunately !)   how  myocardium escapes in the  chronic process of RHD.

Is it really true  ,  myocardium do not get involved in chronic RHD ?

Clinical cardiologists rarely discuss this issue. Pathogists indeed have documented significant lesions within myocardium  . Involvement of left atrial myocardium and  rarely  ventricular myocardium in the sub mitral  zone  can influence the  degree of  MR

* Even in acute rheumatic fever with fulminant carditis , myocardial involvement is  disputed by many  ! . My belief is ,  there will   definitely a subset  in   both acute and  chronic  forms of   RHD   , in which myocardium  gets  involved . In our institute LV dysfunction associated with RHD occur in  up to  5 % of  RHD population .

Importance of knowing the mechanism of MR

Two aspects  appear important

1. Is there a potentially  reversible component in pathology so that we can  wait  before intervention  ?

I have seen children referred for mitral valve replacement due to severe MR  . In due course   MR regress by the time they reach the tertiary center (waiting period included ) At least one child i remember,  the MV surgery was canceled  due to spontaneous regression MR.

It was later found the MR was  more of valve inflammation than degeneration .

* Always think about the possibility of reversible rheumatic MR  in every severe isolated  MR in children (Do not apply this rule in adults or in combined MS or MR  )  Do a ESR, ASO and start an  intensive anti inflammatory therapy  , aspirin with strict penicillin prophylaxis .With this  one can definitely postpone the surgery  in few cases  and  may avoid it altogether !

2. Surgical implication

If we could delineate  the  exact pathology of MR   it will facilitate  the   repair . Annular  reduction and  neo  chordae  etc . Of course ,the surgery could be  very  difficult in scarred mitral valves ,  Dr Sampath kumar *of AIIMS  New delhi , India  would  feel other wise !

*A pioneer in mitral valve repair in chronic  RHD (See reference 2 )

Questions  that need  answers

How is balloon/Surgery  related injury different from rheumatic process ?

Why is  rheumatic  mitral vale  prone for bacterial infection ?

What is the relationship  between  extent of  aortic valve involvement and  degree of mitral valve involvement in RHD ?

Reference

1.http://circ.ahajournals.org/content/94/1/73.full?sid=10599470-3563-4c38-b688-c5fc8c032f96

2. http://icvts.ctsnetjournals.org/cgi/reprint/5/4/356

Books

There two popular books exclusively  for cardiac pathology

1.Silver

2. Renu Virmani

Read Full Post »