Difference between revisions of "Cardiomyopathy"
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*Mitochondrial myopathy. | *[[Mitochondrial myopathy]]. | ||
**Perinuclear clearing on light microscopy due to abundant mitochondria. | **Perinuclear clearing on light microscopy due to abundant mitochondria. | ||
**Atypical mitochondria on [[electron microscopy]]. | **Atypical mitochondria on [[electron microscopy]]. | ||
*Muscular dystrophy. | *[[Muscular dystrophy]]. | ||
*[[Storage disease]]. | *[[Storage disease]]. | ||
Revision as of 04:59, 1 March 2012
Cardiomyopathy, abbreviated as CM, is a domain of cardiology and forensic pathology, as many cardiomyopathies can lead to sudden death.
Overview
Types[1]
- Dilated cardiomyopathy - most common ~ 90%
- Hypertrophic cardiomyopathy
- Restrictive cardiomyopathy - least common
Note: The frequency of the CMs is in alphabetic order dilated, hypertrophic, restrictive.
Dilated cardiomyopathy
General
- Most common of the cardiomyopathies.
Causes:
- Myocarditis - leading cause, usually viral.[2]
- Familial ~ 30% - can be AD with variable penetrance, AR, X-linked.
- In the forensic context, usually caused by alcoholism.[3]
Microscopic
Features:
- Epicardial fibrosis.
- Usually non-specific.
DDx:
- Mitochondrial myopathy.
- Perinuclear clearing on light microscopy due to abundant mitochondria.
- Atypical mitochondria on electron microscopy.
- Muscular dystrophy.
- Storage disease.
IHC
Work-up for muscular dystrophy:
- Dystrophin.
Work-up for mitochondrial disease:
- COX.
- SDH.
Hypertrophic cardiomyopathy
- Abbreviated HCM.
General
- Genetic.
- Classic cause of sudden death in young athletes.[4]
Gross
- Classic: septum:left ventricular free wall = 1.5:1.0.[5]
Microscopic
Features:[6]
- Myocardial fibres have increased transverse size (~40 micrometres) - key feature.
- Normal myocardial fibre width = 15 micrometres.
- Haphazard arrangement of myocardial fibres;[7] "basket weave" pattern.
- Interstitial fibrosis.
- NOT diffuse patch/area as in an old myocardial infarction.
- Large hyperchromatic nuclei (~3x fibroblast nucleus).[8]
Notes:
- Easiest to identify if sections are perpendicular to the long axis of the myocytes.
Images:
Variants
Hypertrophic obstructive cardiomyopathy
- Abbreviated HOCM.
- Considered to be a variant of HCM.
- Historically known as idiopathic hypertrophic subaortic stenosis (IHSS).
Apical HCM
- AKA Japanese variant.[9]
- Mid-ventricular septal thickening or apical thickening (NOT subaortic hypertrophy).
Restrictive cardiomyopathy
- Uncommon form of cardiomyopathy.
Etiology
Multiple causes - an incomplete list:[10]
- Hemochromatosis - rare.[11]
- Amyloidosis.
- Classically described as "stiff" or "rubbery".
- Sarcoidosis.
- Storage diseases (Pompe disease).
- Eosinophilic endocarditis (Loeffler Endocarditis).
Arrhythmogenic right ventricular cardiomyopathy
- Abbreviated ARVC.
General
- Previously known as "arrhythmogenic right ventricular dysplasia" (abbreviated ARVD).
- Associated with sudden cardiac death in "young people".[12]
- Male > female.
Etiology
- Genetic - mutations in:
- Desmosomal proteins, especially plakoglobin and desmoplakin.
- Usually autosomal dominant.
- Autosomal recessive variant: Naxos syndrome.[13]
- Clinical: wooly hair, palmar & plantar keratoses.
Microscopic
Features:[14]
- "Moth-eaten" appearance:
- Loss of myocytes, replaced by:
- Fat and/or
- Scar tissue.
- Loss of myocytes, replaced by:
- +/-Inflammation (lymphocytes, macrophages).
- Myocytes have "bubbly" appearance with loss of myofibres and cross-striations.
Images:
Gross features
Gross:[14]
- RV wall thinning/replacement with fat.
- Especially fat where fat is not usually seen - posterior RV wall, RVOT.
- Septum usually has relative sparing
- Thus, endomyocardial biopsy is not reliable.
- +/-Aneurysms/dilation.
Noncompaction cardiomyopathy
Etiology
- Genetic - LVNC1 gene.[15]
- May be associated with dilation.[15]
- Rare.
- Not clear whether it is a unique entity.[16]
Gross
- Prominent "mesh-like" trabeculae carnae.
- Enlarged intertrabecular recesses.[17]
See also
- Heart.
- Cardiac sarcoidosis.
- Amyloidosis - covers cardiac amyloidosis.
References
- ↑ Cotran, Ramzi S.; Kumar, Vinay; Fausto, Nelson; Nelso Fausto; Robbins, Stanley L.; Abbas, Abul K. (2005). Robbins and Cotran pathologic basis of disease (7th ed.). St. Louis, Mo: Elsevier Saunders. pp. 601. ISBN 0-7216-0187-1.
- ↑ Luk A, Ahn E, Soor GS, Butany J (March 2009). "Dilated cardiomyopathy: a review". J. Clin. Pathol. 62 (3): 219–25. doi:10.1136/jcp.2008.060731. PMID 19017683.
- ↑ DiMaio, Vincent J.M.; Dana, Suzanna E. (2006). Handbook of Forensic Pathology (2nd ed.). CRC Press. pp. 43. ISBN 978-0849392870.
- ↑ Gojanovic B, Feihl F, Gremion G, Waeber B (February 2007). "[Sudden death in young athletes]" (in German). Praxis (Bern 1994) 96 (6): 189-98. PMID 17330410.
- ↑ JB. 9 June 2011.
- ↑ Cotran, Ramzi S.; Kumar, Vinay; Fausto, Nelson; Nelso Fausto; Robbins, Stanley L.; Abbas, Abul K. (2005). Robbins and Cotran pathologic basis of disease (7th ed.). St. Louis, Mo: Elsevier Saunders. pp. 601-3. ISBN 0-7216-0187-1.
- ↑ DiMaio, Vincent J.M.; Dana, Suzanna E. (2006). Handbook of Forensic Pathology (2nd ed.). CRC Press. pp. 44. ISBN 978-0849392870.
- ↑ CK. 14 October 2010.
- ↑ Reddy, M.; Thatai, D.; Bernal, J.; Pradhan, J.; Afonso, L. (Jul 2008). "Apical hypertrophic cardiomyopathy: potential utility of Strain imaging.". Eur J Echocardiogr 9 (4): 560-2. doi:10.1016/j.euje.2007.02.004. PMID 17392031.
- ↑ DiMaio, Vincent J.M.; Dana, Suzanna E. (2006). Handbook of Forensic Pathology (2nd ed.). CRC Press. pp. 44-5. ISBN 978-0849392870.
- ↑ Cutler, DJ.; Isner, JM.; Bracey, AW.; Hufnagel, CA.; Conrad, PW.; Roberts, WC.; Kerwin, DM.; Weintraub, AM. (Dec 1980). "Hemochromatosis heart disease: an unemphasized cause of potentially reversible restrictive cardiomyopathy.". Am J Med 69 (6): 923-8. PMID 7446557.
- ↑ Sudden cardiac death due to hypertrophic cardiomyopathy can be reduced by pre-participation cardiovascular screening in young athletes. URL: http://eurheartj.oxfordjournals.org/cgi/content/full/27/18/2152. Accessed on: 16 December 2009.
- ↑ http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=601214
- ↑ 14.0 14.1 URL: http://emedicine.medscape.com/article/1612324-overview.
- ↑ 15.0 15.1 Online 'Mendelian Inheritance in Man' (OMIM) 604169
- ↑ Paterick TE, Gerber TC, Pradhan SR, Lindor NM, Tajik AJ (2010). "Left ventricular noncompaction cardiomyopathy: what do we know?". Rev Cardiovasc Med 11 (2): 92–9. PMID 20700091.
- ↑ Chin TK, Perloff JK, Williams RG, Jue K, Mohrmann R (August 1990). "Isolated noncompaction of left ventricular myocardium. A study of eight cases". Circulation 82 (2): 507–13. PMID 2372897.