Heart valves: Difference between revisions

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*Anitschkow's cells (caterpillar cells)?
*Anitschkow's cells (caterpillar cells)?
**Rheumatic heart disease.
**Rheumatic heart disease.
***Image: [http://commons.wikimedia.org/wiki/File:Anitschkow_Myocytes_in_an_Aschoff_Body,_Rheumatic_Myocarditis.jpg Anitschkow cells (WC)].


*Aschoff bodies?
*Aschoff bodies?
**Rheumatic heart disease.
**Rheumatic heart disease.
***Image: [http://commons.wikimedia.org/wiki/File:Aschoff_Body_in_Rheumatic_Myocarditis.jpg Aschoff body (WC)].


*Thickening of spongiosa (layer)?
*Thickening of spongiosa (layer)?
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===General===
===General===
*Usually affects the mitral valve.
*Usually affects the mitral valve.
*female > male,<ref>[http://emedicine.medscape.com/article/759004-overview]</ref> disputed by Toronto data<ref name=leong>{{cite journal |author=Leong SW, Soor GS, Butany J, Henry J, Thangaroopan M, Leask RL |title=Morphological findings in 192 surgically excised native mitral valves |journal=Can J Cardiol |volume=22 |issue=12 |pages=1055-61 |year=2006 |month=October |pmid=17036100 |doi= |url=}}</ref>
*Female > male,<ref>[http://emedicine.medscape.com/article/759004-overview]</ref> disputed by Toronto data.<ref name=leong>{{cite journal |author=Leong SW, Soor GS, Butany J, Henry J, Thangaroopan M, Leask RL |title=Morphological findings in 192 surgically excised native mitral valves |journal=Can J Cardiol |volume=22 |issue=12 |pages=1055-61 |year=2006 |month=October |pmid=17036100 |doi= |url=}}</ref>
*Assoc. with [[Marfan's syndrome]] and [[Turner's syndrome]].<ref>{{cite journal |author=Wigle ED, Rakowski H, Ranganathan N, Silver MC |title=Mitral valve prolapse |journal=Annu. Rev. Med. |volume=27 |issue= |pages=165–80 |year=1976 |pmid=779595 |doi=10.1146/annurev.me.27.020176.001121 |url=}}</ref>
*Associated with [[Marfan's syndrome]] and [[Turner's syndrome]].<ref>{{cite journal |author=Wigle ED, Rakowski H, Ranganathan N, Silver MC |title=Mitral valve prolapse |journal=Annu. Rev. Med. |volume=27 |issue= |pages=165–80 |year=1976 |pmid=779595 |doi=10.1146/annurev.me.27.020176.001121 |url=}}</ref>


===Gross===
===Gross===
Features<ref>PBoD P.591</ref>
Features<ref>PBoD P.591.</ref>
*no commissural fusion  
*No commissural fusion.
**commissural fusion typical of rheumatic heart disease
**Commissural fusion typical of rheumatic heart disease.
*thickened
*Thickened.
*rubbery consistency
*Rubbery consistency.
*reactive/secondary changes
*Reactive/secondary changes.
**fibrosis due to prolapse/abnormal contact of valve with other structures
**Fibrosis due to prolapse/abnormal contact of valve with other structures.
**clots/organized thrombus - due to stasis
**Clots/organized thrombus - due to stasis.


===Microscopic===
===Microscopic===
Line 97: Line 95:


====Staining====
====Staining====
*Movat stain
*Movat stain.
**acid fuchsin, alcian blue, crocein scarlet, elastic hematoxylin, pathology consultation, and saffron.<ref>[http://www.mayomedicallaboratories.com/test-catalog/Overview/9832]</ref><ref name=penn_med>Modified Movat's Pentachrome Stain. University Penn Medicine. URL: [http://www.med.upenn.edu/mcrc/histology_core/movat.shtml http://www.med.upenn.edu/mcrc/histology_core/movat.shtml]. Accessed on: January 29, 2009.</ref>
**Acid fuchsin, alcian blue, crocein scarlet, elastic hematoxylin, pathology consultation, and saffron.<ref>[http://www.mayomedicallaboratories.com/test-catalog/Overview/9832]</ref><ref name=penn_med>Modified Movat's Pentachrome Stain. University Penn Medicine. URL: [http://www.med.upenn.edu/mcrc/histology_core/movat.shtml http://www.med.upenn.edu/mcrc/histology_core/movat.shtml]. Accessed on: January 29, 2009.</ref>


Interpretation of Movat stain:<ref name=penn_med/>
Interpretation of Movat stain:<ref name=penn_med/>
*black = nuclei and elastic fibers
*black = nuclei and elastic fibers.
*yellow = collagen and reticular fibers
*yellow = collagen and reticular fibers.
*blue = mucin, ground substance
*blue = mucin, ground substance.
*red (intense) = fibrin
*red (intense) = fibrin.
*red = muscle
*red = muscle.


==Rheumatic heart disease==
==Rheumatic heart disease==
===General===
===General===
*Classically leads to mitral valve stenosis.
*Classically leads to mitral valve stenosis.
**Rheumatic fever accounts for 99% of mitral stenosis<ref>PBoD P.594</ref>
**Rheumatic fever accounts for 99% of mitral stenosis<ref>PBoD P.594.</ref>
*Disease less frequent today - as streptococcal pharynigits is treated.
*Disease less frequent today - as streptococcal pharynigits is treated.


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===Microscopic===
===Microscopic===
Features:<ref>PBoD P.593</ref>
Features:<ref>PBoD P.593.</ref>
*Caterpillar cell (aka Anitschkow cells)
*Caterpillar cell (aka Anitschkow cells)
**Abundant eosinophilic cytoplasm.
**Abundant eosinophilic cytoplasm.
Line 131: Line 129:
**Well-defined central ovoid nucleus with a prominent wavy ribbon-like chromatin -- looks vaguely like a caterpillar with some immagination.
**Well-defined central ovoid nucleus with a prominent wavy ribbon-like chromatin -- looks vaguely like a caterpillar with some immagination.
**Pathognomonic for rheumatic fever.
**Pathognomonic for rheumatic fever.
**Image: [http://en.wikipedia.org/wiki/File:Anitschkow_Myocytes_in_an_Aschoff_Body,_Rheumatic_Myocarditis.jpg Anitschkow myocytes] - wikipedia.org.
 
*Aschoff bodies:
*Aschoff bodies:
**Usually in the heart itself,
**Usually in the heart itself,
**Jumbled collagen, eosinophilic, and
**Jumbled collagen, eosinophilic, and
**Surrounded by lymphocytes (T cells) +/- plasma cells.
**Surrounded by lymphocytes (T cells) +/- plasma cells.
Images:
*[http://commons.wikimedia.org/wiki/File:Aschoff_Body_in_Rheumatic_Myocarditis.jpg Aschoff body (WC)].
*[http://en.wikipedia.org/wiki/File:Anitschkow_Myocytes_in_an_Aschoff_Body,_Rheumatic_Myocarditis.jpg Anitschkow myocytes (WC)].


==Endocarditis==
==Endocarditis==

Revision as of 19:10, 13 May 2010

Heart valves are the domain of the cardiac surgeon and their bread & butter.

Clinical

General

  • Insufficiency (regurgitant flow) - murmur in diastole.
  • Stenosis (decreased flow area) - murmur in systole.

Pathology

Which valves cause the most trouble?

  • Mostly those on the left side (subjected to higher pressures), i.e. mitral valve (or left atrioventricular v.) and aortic valve.

Aortic stenosis - cause?

  • Mostly "calcific aortic stenosis".

Quick approach to valves

Gross

  • Calcification?
    • Consider calcific stenosis.
  • Vegetations?
    • Consider infective endocarditis.
  • Thin?
    • Consider myxomatous change.

Microscopic

  • Inflammation?
    • Consider endocarditis.
  • Anitschkow's cells (caterpillar cells)?
    • Rheumatic heart disease.
  • Aschoff bodies?
    • Rheumatic heart disease.
  • Thickening of spongiosa (layer)?
    • Myxomatous change?

Normal histology

Aortic valve

General

  • covered by endothelium
  • mostly avascular (nutrients supplied by diffusion)

Terminology

  • base - closest to the aortic wall
  • free edge - closest to the centre of the valve/interacts with other valve cusps

Three layers (from proximal (ventricular side) to distal (valsalva side)):[1]

  1. Ventricularis.
    • Elastic tissue.
  2. Spongiosa.
    • Loose connective tissue.
  3. Fibrosa.
    • Mostly collagen, thickest part in a normal valve.

Mitral valve

Gross

  • Cordae tendinae

Histology

  • Similar to the aortic valve.

Calcific aortic stenosis

General

  • Somewhat similar to atherosclerosis; however, considered a separate entity[2]
  • Mitral valve is usually normal.

Micro

Features:[3]

  • Affects the valsalva side of the valve.
    • It affects the fibrosa.
  • Primarily at the base of the valve, i.e. there is relative sparing the free edge.

Myxomatous degeneration

General

Gross

Features[7]

  • No commissural fusion.
    • Commissural fusion typical of rheumatic heart disease.
  • Thickened.
  • Rubbery consistency.
  • Reactive/secondary changes.
    • Fibrosis due to prolapse/abnormal contact of valve with other structures.
    • Clots/organized thrombus - due to stasis.

Microscopic

  • Thinning of fibrosa layer.
  • Thickening of spongiosa layer with mucoid (myxomatous) material. (key feature).
  • +/-Secondary changes (due to valvular dysfunction): thrombi, fibrosis.

Staining

  • Movat stain.
    • Acid fuchsin, alcian blue, crocein scarlet, elastic hematoxylin, pathology consultation, and saffron.[8][9]

Interpretation of Movat stain:[9]

  • black = nuclei and elastic fibers.
  • yellow = collagen and reticular fibers.
  • blue = mucin, ground substance.
  • red (intense) = fibrin.
  • red = muscle.

Rheumatic heart disease

General

  • Classically leads to mitral valve stenosis.
    • Rheumatic fever accounts for 99% of mitral stenosis[10]
  • Disease less frequent today - as streptococcal pharynigits is treated.

Gross

  • "Fish-mouth appearance".
    • Slit-like morphology; ellipical cross-sectional flow area (mitral valve) has an abnormally small semi-minor axis[11] axis due to valve thickening.
    • Image: Fish-mouth appearance (pipe) - principia-eng.com.
  • Significant valvular thickening.
  • Thickening of the cordae tendinae.

Microscopic

Features:[12]

  • Caterpillar cell (aka Anitschkow cells)
    • Abundant eosinophilic cytoplasm.
    • Moderately-poorly defined cell border.
    • Well-defined central ovoid nucleus with a prominent wavy ribbon-like chromatin -- looks vaguely like a caterpillar with some immagination.
    • Pathognomonic for rheumatic fever.
  • Aschoff bodies:
    • Usually in the heart itself,
    • Jumbled collagen, eosinophilic, and
    • Surrounded by lymphocytes (T cells) +/- plasma cells.

Images:

Endocarditis

General

  • Infection of the endocardium - often involves the valves (which are covered by endocardium).
  • Before the time of antibiotics -- 100% fatal.

Clinical

  • Diagnosed (clinically) using the Duke criteria.[13][14]
    • positive blood cultures.
    • cardiac involvement - vegetation.
    • +/-febrile.

Microscopic

  • Inflammatory infiltrate (key feature @ low power)
    • +/-Plasma cells,
    • +/-Neutrophils.
  • Microorganisms (key feature - diagnostic)
    • Hard to see (even at high power).

Stains

  • GMS (Gomori Methenamine-silver stain)
    • look for fungi.
  • Gram stain
    • look for bacteria.

Biscupid aortic valve

General

  • Aortic valve usually tricuspid.
  • 1-2% of general population.[15]
  • Inherited in autosomal dominant pattern.

Significance

  • Associated with ascending aortic aneurysms - x10 risk of dissection vs. normal population[15]
  • 30% develop serious morbidity.[15]
  • Associated with early development of calcific aortic stenosis.

Tumours

Main article: Cardiac tumours

Papillary fibroelastomas are the most common tumour of the valve.

See also

References

  1. ↑ PBoD P.558.
  2. ↑ Otto CM (September 2008). "Calcific aortic stenosis--time to look more closely at the valve". N. Engl. J. Med. 359 (13): 1395-8. doi:10.1056/NEJMe0807001. PMID 18815402.
  3. ↑ PBoD P.590
  4. ↑ [1]
  5. ↑ Leong SW, Soor GS, Butany J, Henry J, Thangaroopan M, Leask RL (October 2006). "Morphological findings in 192 surgically excised native mitral valves". Can J Cardiol 22 (12): 1055-61. PMID 17036100.
  6. ↑ Wigle ED, Rakowski H, Ranganathan N, Silver MC (1976). "Mitral valve prolapse". Annu. Rev. Med. 27: 165–80. doi:10.1146/annurev.me.27.020176.001121. PMID 779595.
  7. ↑ PBoD P.591.
  8. ↑ [2]
  9. ↑ 9.0 9.1 Modified Movat's Pentachrome Stain. University Penn Medicine. URL: http://www.med.upenn.edu/mcrc/histology_core/movat.shtml. Accessed on: January 29, 2009.
  10. ↑ PBoD P.594.
  11. ↑ http://en.wikipedia.org/wiki/Ellipse
  12. ↑ PBoD P.593.
  13. ↑ http://www.medcalc.com/endocarditis.html
  14. ↑ Durack DT, Lukes AS, Bright DK (March 1994). "New criteria for diagnosis of infective endocarditis: utilization of specific echocardiographic findings. Duke Endocarditis Service". Am. J. Med. 96 (3): 200-9. PMID 8154507.
  15. ↑ 15.0 15.1 15.2 Vallely MP, Semsarian C, Bannon PG (October 2008). "Management of the ascending aorta in patients with bicuspid aortic valve disease". Heart Lung Circ 17 (5): 357-63. doi:10.1016/j.hlc.2008.01.007. PMID 18514024.
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