6 myocarditis
TRANSCRIPT
![Page 1: 6 myocarditis](https://reader036.vdocuments.net/reader036/viewer/2022062307/554aff5ab4c9059f798b5463/html5/thumbnails/1.jpg)
Myocarditis
![Page 2: 6 myocarditis](https://reader036.vdocuments.net/reader036/viewer/2022062307/554aff5ab4c9059f798b5463/html5/thumbnails/2.jpg)
• An inflammatory process of myocardium that result into the injury to cardiac myocytes.
![Page 3: 6 myocarditis](https://reader036.vdocuments.net/reader036/viewer/2022062307/554aff5ab4c9059f798b5463/html5/thumbnails/3.jpg)
Major Causes of Myocarditis
INFECTIONSViruses(coxsackie,influenza,HIV,CMV)Chlamydia(C.Psittaci)Rickettsiae(R.typhi)Bacteria(Cornybacterium diphtheriae,Nisseria men
ingococcus,Borellia)Fungi(Candida)Protozoa(trypanosoma Cruzi,toxoplasmosis)Helminths(trichinosis)
![Page 4: 6 myocarditis](https://reader036.vdocuments.net/reader036/viewer/2022062307/554aff5ab4c9059f798b5463/html5/thumbnails/4.jpg)
IMMUNE-MEDIATED REACTIONS
• Post viral• Post Streptococcal• SLE• Drug hypersensitivity(e.g.methyldopa,sulphonamides)• Transplant rejections
UNKNOWN
Sarcoidosis
Giant cell myocarditis
![Page 5: 6 myocarditis](https://reader036.vdocuments.net/reader036/viewer/2022062307/554aff5ab4c9059f798b5463/html5/thumbnails/5.jpg)
Morphology
• Active phase – heart may be normal or dilated• Advanced stages: the ventricular myocardium is fl
abby and often mottled. • Mural thrombi may be present in any chamber.
• Mononuclear interstitial inflammatory infiltrate associated with focal myocyte necrosis.
• Later-inflammatory lesions either resolve, leaving no residual changes, or heal by progressive fibrosis.
![Page 6: 6 myocarditis](https://reader036.vdocuments.net/reader036/viewer/2022062307/554aff5ab4c9059f798b5463/html5/thumbnails/6.jpg)
![Page 7: 6 myocarditis](https://reader036.vdocuments.net/reader036/viewer/2022062307/554aff5ab4c9059f798b5463/html5/thumbnails/7.jpg)
Hypersensitivity myocarditis- perivascular interstitial infiltrates, composed of lymphocytes, macrophages, and a high proportion of eosinophils
Giant-cell myocarditis (uncertain cause)- • inflammatory cellular infiltrate containing multinu
cleate giant cells interspersed with lymphocytes, eosinophils, plasma cells, and macrophages.
• Chagas disease: trypanosoma cruzi, mixed inflammatory cell infiltrate.
![Page 8: 6 myocarditis](https://reader036.vdocuments.net/reader036/viewer/2022062307/554aff5ab4c9059f798b5463/html5/thumbnails/8.jpg)
![Page 9: 6 myocarditis](https://reader036.vdocuments.net/reader036/viewer/2022062307/554aff5ab4c9059f798b5463/html5/thumbnails/9.jpg)
Chagas disease - scattered trypanosomes accompanied by an inflammatory infiltrate of neutrophils, lymphocytes, macrop
hages, and occasional eosinophils
![Page 10: 6 myocarditis](https://reader036.vdocuments.net/reader036/viewer/2022062307/554aff5ab4c9059f798b5463/html5/thumbnails/10.jpg)
Clinical Features
• May be asymptomatic- recover completely without sequelae
• Features of heart failure or arrhythmias, occasionally with sudden death.
• fatigue, dyspnea, palpitations, precordial discomfort, and fever.
• Occasionally, patients develop DCM - late complication of myocarditis.
![Page 11: 6 myocarditis](https://reader036.vdocuments.net/reader036/viewer/2022062307/554aff5ab4c9059f798b5463/html5/thumbnails/11.jpg)
OTHER CAUSES OF MYOCARDIAL DISEASE
Adriamycin, doxorubicin and daunorubicin
Catecholamines
Cyclophosphamide
Amyloidosis
![Page 12: 6 myocarditis](https://reader036.vdocuments.net/reader036/viewer/2022062307/554aff5ab4c9059f798b5463/html5/thumbnails/12.jpg)
Amyloidosis
• caused by deposition of an insoluble extracellular fibrillar deposits of protein fragments that are prone to forming β-pleated sheets.
• Cardiac amyloidosis may appear along with systemic amyloidosis
• restricted to the heart, senile cardiac amyloidosis.
• amyloid deposits generally occur in the ventricles and atria.
• caused by the deposition of transthyretin
![Page 13: 6 myocarditis](https://reader036.vdocuments.net/reader036/viewer/2022062307/554aff5ab4c9059f798b5463/html5/thumbnails/13.jpg)
Morphology
• normal to firm and rubbery. • Usually the chambers are of normal size• Can be dilated and have thickened walls. • Numerous small, semi-translucent nodules resem
bling drips of wax • Eosinophilic deposits of amyloid may be found in t
he interstitium, conduction tissue, valves, endocardium, pericardium, and small intramural coronary arteries
• special stains - Congo red- classic apple-green birefringence when viewed under polarized light
![Page 14: 6 myocarditis](https://reader036.vdocuments.net/reader036/viewer/2022062307/554aff5ab4c9059f798b5463/html5/thumbnails/14.jpg)
• Amyloid deposits often form rings around cardiac myocytes and capillaries.
• Intramural arteries and arterioles may have sufficient amyloid in their walls to compress and occlude their lumens, inducing myocardial ischemia (“small-vessel disease”).
![Page 15: 6 myocarditis](https://reader036.vdocuments.net/reader036/viewer/2022062307/554aff5ab4c9059f798b5463/html5/thumbnails/15.jpg)
![Page 16: 6 myocarditis](https://reader036.vdocuments.net/reader036/viewer/2022062307/554aff5ab4c9059f798b5463/html5/thumbnails/16.jpg)
Pericarditis
• Diseases of the pericardium include inflammatory conditions and effusions.
• Isolated pericardial disease is unusual, and pericardial lesions are almost always associated with disease in other portions of the heart or surrounding structures, or are secondary to a systemic disorder.
![Page 17: 6 myocarditis](https://reader036.vdocuments.net/reader036/viewer/2022062307/554aff5ab4c9059f798b5463/html5/thumbnails/17.jpg)
Pericarditis
• Primary pericarditis is uncommon.• In most cases it is caused by infection.
– Viruses, bacteria and fungi– Secondary to acute MI, cardiac surgery, irradiation to
the mediastinum, or processes involving other thoracic structures (e.g., pneumonia or pleuritis).
– Uremia is the most common systemic disorder associated with pericarditis.
– Rheumatic fever, SLE, and metastatic malignancies.
![Page 18: 6 myocarditis](https://reader036.vdocuments.net/reader036/viewer/2022062307/554aff5ab4c9059f798b5463/html5/thumbnails/18.jpg)
Morphology
Fibrinous pericarditis (uremia): an irregular appearance to the pericardial surface (so-called bread-and-butter pericarditis).
Fibrinopurulent (in acute bacterial pericarditis):Areas of frank pus;
Tuberculous pericarditis: areas of caseation.
Chronic pericarditis: The appearance of chronic pericarditis ranges from delicate adhesions to dense, fibrotic scars that obliterate the pericardial space. In extreme cases the heart is so completely encased by dense fibrosis that it cannot expand normally during diastole, so-called constrictive pericarditis.
![Page 19: 6 myocarditis](https://reader036.vdocuments.net/reader036/viewer/2022062307/554aff5ab4c9059f798b5463/html5/thumbnails/19.jpg)
Clinical Features
• Atypical chest pain, not related to exertion and often worse on reclining, and a prominent friction rub.
• • When associated with significant fluid accumulatio
n, acute pericarditis can cause cardiac tamponade, with declining cardiac output and shock.
• Chronic constrictive pericarditis produces a combination of right-sided venous distention and low cardiac output, similar to restrictive cardiomyopathy.
![Page 20: 6 myocarditis](https://reader036.vdocuments.net/reader036/viewer/2022062307/554aff5ab4c9059f798b5463/html5/thumbnails/20.jpg)
• Cardiomyopathies
![Page 21: 6 myocarditis](https://reader036.vdocuments.net/reader036/viewer/2022062307/554aff5ab4c9059f798b5463/html5/thumbnails/21.jpg)
Cardiomyopathies
• The cardiomyopathies are a group of diseases that primarily affect the heart muscle and are not the result of congenital, acquired valvular, hypertensive, coronary arterial, or pericardial abnormalities
• Primary cardiomyopathies -confined to the heart muscle
• Secondary cardiomyopathies -myocardial involvement as a component of a systemic or multiorgan disorder.
![Page 22: 6 myocarditis](https://reader036.vdocuments.net/reader036/viewer/2022062307/554aff5ab4c9059f798b5463/html5/thumbnails/22.jpg)
Classification of cardiomyopathies
• Primary myocardial involvement
1. Idiopthic (D,R,H)
2. Familial (D,R,H)
3. Eosinophilic endomyocardial disease (R)
4. Endomyocardial fibrosis (R)
![Page 23: 6 myocarditis](https://reader036.vdocuments.net/reader036/viewer/2022062307/554aff5ab4c9059f798b5463/html5/thumbnails/23.jpg)
Secondary myocardial involvement
• CARDIAC INFECTIONS – Viruses, Chlamydia; Rickettsia; Bacteria; Fun
gi; Protozoa
• TOXINS – Alcohol, Cobalt, Catecholamines, CO, Lithium,
Hydrocarbons, Arsenic, Cyclophosphamide, Doxorubicin and daunorubicin
![Page 24: 6 myocarditis](https://reader036.vdocuments.net/reader036/viewer/2022062307/554aff5ab4c9059f798b5463/html5/thumbnails/24.jpg)
• METABOLIC – Hyperthroidism, Hypothyroidism, Hyperkalemi
a, Hypokalemia, Nutritional deficiency (protein, thiamine, other avitaminoses), Hemochromatosis
• NEUROMUSCULAR DISEASE – Friedreich ataxia, Muscular dystrophy, Conge
nital atrophies
![Page 25: 6 myocarditis](https://reader036.vdocuments.net/reader036/viewer/2022062307/554aff5ab4c9059f798b5463/html5/thumbnails/25.jpg)
• STORAGE DISORDERS AND OTHER DEPOSITIONS – Hunter-Hurler syndrome, Glycogen storage disease, Fa
bry disease, Amyloidosis
• INFILTRATIVE – Leukemia, Carcinomatosis,Sarcoidosis, Radiation-indu
ced fibrosis
• IMMUNOLOGICAL – Myocarditis (several forms) , Post-transplant rejection
![Page 26: 6 myocarditis](https://reader036.vdocuments.net/reader036/viewer/2022062307/554aff5ab4c9059f798b5463/html5/thumbnails/26.jpg)
Clinical Classification of Cardiomyopathies
• Dilated: Left and/or right ventricular enlargement, impaired systolic function, congestive heart failure, arrhythmias, emboli
• Restrictive: Endomyocardial scarring or myocardial infiltration resulting in restriction to left and/or right ventricular filling
• Hypertrophic: Disproportionate left ventricular hypertrophy, typically involving septum more than free wall, with or without an intraventricular systolic pressure gradient; usually of a nondilated left ventricular cavity
![Page 27: 6 myocarditis](https://reader036.vdocuments.net/reader036/viewer/2022062307/554aff5ab4c9059f798b5463/html5/thumbnails/27.jpg)
Diagnosed as an isolated finding or associated with other congenital heart anomalies
![Page 28: 6 myocarditis](https://reader036.vdocuments.net/reader036/viewer/2022062307/554aff5ab4c9059f798b5463/html5/thumbnails/28.jpg)
![Page 29: 6 myocarditis](https://reader036.vdocuments.net/reader036/viewer/2022062307/554aff5ab4c9059f798b5463/html5/thumbnails/29.jpg)
DILATED CARDIOMYOPATHY (DCM)
• Progressive four chamber hypertrophy and dilation
• Contractile (systolic) dysfunction
• Can occur at any age
• Slow progressive to CHF.
• It is sometimes called congestive cardiomyopathy.
![Page 30: 6 myocarditis](https://reader036.vdocuments.net/reader036/viewer/2022062307/554aff5ab4c9059f798b5463/html5/thumbnails/30.jpg)
Pathogenesis
• Genetic influence
• Various acquired myocardial insults
• Myocarditis
• Alcohol or other toxicity
• Pregnancy associated.
![Page 31: 6 myocarditis](https://reader036.vdocuments.net/reader036/viewer/2022062307/554aff5ab4c9059f798b5463/html5/thumbnails/31.jpg)
Genetic influences
• 20%- 50% - is familial and caused by inherited genetic abnormalities.
• Autosomal-dominant inheritance is the predominant pattern
• Most commonly affect genes that encode cytoskeletal proteins (dystrophin). Duchene and Beker MD
• Mutation in enzyme involved in beta-oxidation of fatty acid
![Page 32: 6 myocarditis](https://reader036.vdocuments.net/reader036/viewer/2022062307/554aff5ab4c9059f798b5463/html5/thumbnails/32.jpg)
• Myocarditis (postviral). – DCM is a consequence of myocarditis.
• Alcohol and other toxins
– No morphologic features serve to distinguish alcoholic cardiomyopathy from DCM of other etiologies.
– Chronic alcoholism may be associated with thiamine deficiency.
![Page 33: 6 myocarditis](https://reader036.vdocuments.net/reader036/viewer/2022062307/554aff5ab4c9059f798b5463/html5/thumbnails/33.jpg)
![Page 34: 6 myocarditis](https://reader036.vdocuments.net/reader036/viewer/2022062307/554aff5ab4c9059f798b5463/html5/thumbnails/34.jpg)
Morphology
• The histologic abnormalities in DCM are nonspecific and usually do not point to a specific etiologic agent.
• Heart is usually enlarged, heavy (>2-3X), and flabby
• Mural thrombi are common• No primary valvular alterations• Most muscle - are hypertrophied with enlarged nuc
lei• Some are attenuated, stretched, and irregular. • Interstitial and endocardial fibrosis –present
![Page 35: 6 myocarditis](https://reader036.vdocuments.net/reader036/viewer/2022062307/554aff5ab4c9059f798b5463/html5/thumbnails/35.jpg)
![Page 36: 6 myocarditis](https://reader036.vdocuments.net/reader036/viewer/2022062307/554aff5ab4c9059f798b5463/html5/thumbnails/36.jpg)
Clinical Features• May occur at any age ( common 20 –50yrs). • CHF • MR & Arrhythmias• Ejection fractions < 25% • 50%- die within 2 years• 25% survive > 5 years• Death - cardiac failure or arrhythmia• Embolism from dislodgment of an intracardiac thrombus ca
n occur. • Cardiac transplantation is frequently done,
![Page 37: 6 myocarditis](https://reader036.vdocuments.net/reader036/viewer/2022062307/554aff5ab4c9059f798b5463/html5/thumbnails/37.jpg)
HYPERTROPHIC CARDIOMYOPATHY
• Characterized by myocardial hypertrophy, abnormal diastolic filling and in 1/3 cases-intermittent ventricular outflow obstruction.
• The heart is thick-walled, heavy, and hypercontracting
• Causes primarily diastolic dysfunction; systolic function is usually preserved.
![Page 38: 6 myocarditis](https://reader036.vdocuments.net/reader036/viewer/2022062307/554aff5ab4c9059f798b5463/html5/thumbnails/38.jpg)
Pathogenesis
• Mutations of genes encoding sarcomeric proteins.
• Mutations - gene encoding β-myosin heavy chain (β-MHC, cardiac TnT, α-tropomyosin, and myosin-binding protein C (MYBP-C)
![Page 39: 6 myocarditis](https://reader036.vdocuments.net/reader036/viewer/2022062307/554aff5ab4c9059f798b5463/html5/thumbnails/39.jpg)
Morphology
• Massive myocardial hypertrophy, without ventricular dilation
• Classic pattern is disproportionate thickening of the ventricular septum as compared with the free wall of the left ventricle
• On cross-section- “banana-like” left ventricle
![Page 40: 6 myocarditis](https://reader036.vdocuments.net/reader036/viewer/2022062307/554aff5ab4c9059f798b5463/html5/thumbnails/40.jpg)
• Histologic Features –– Extensive myocyte hypertrophy to a degree unusual i
n other conditions, with transverse myocyte diameters frequently greater than 40 μm (15 μm);
– Haphazard disarray of bundles of myocytes, individual myocytes, and contractile elements in sarcomeres within cells (termed myofiber disarray)
– Interstitial and replacement fibrosis
![Page 41: 6 myocarditis](https://reader036.vdocuments.net/reader036/viewer/2022062307/554aff5ab4c9059f798b5463/html5/thumbnails/41.jpg)
![Page 42: 6 myocarditis](https://reader036.vdocuments.net/reader036/viewer/2022062307/554aff5ab4c9059f798b5463/html5/thumbnails/42.jpg)
Clinical Features
• Exertional dyspnea
• Systolic ejection murmur
• Atrial fibrillation
• Mural thrombus formation
• Ventricular arrhythmias
• Sudden
![Page 43: 6 myocarditis](https://reader036.vdocuments.net/reader036/viewer/2022062307/554aff5ab4c9059f798b5463/html5/thumbnails/43.jpg)
RESTRICTIVE CARDIOMYOPATHY
• Characterized by primary decrease in ventricular compliance, resulting in impaired ventricular filling during diastole.
• May be idiopathic or associated with distinct diseases - principally radiation fibrosis, amyloidosis, sarcoidosis, metastatic tumors, inborn errors of metabolism.
![Page 44: 6 myocarditis](https://reader036.vdocuments.net/reader036/viewer/2022062307/554aff5ab4c9059f798b5463/html5/thumbnails/44.jpg)
Morphology
• Ventricles are of normal size or slightly enlarged
• Cavities are not dilated
• Myocardium is firm and noncompliant
Microscopy:
• May be only patchy or diffuse interstitial fibrosis
![Page 45: 6 myocarditis](https://reader036.vdocuments.net/reader036/viewer/2022062307/554aff5ab4c9059f798b5463/html5/thumbnails/45.jpg)
• Endomyocardial fibrosis - disease of children and young adults
• Fibrous tissue markedly diminishes the volume and compliance of affected chambers - induces a restrictive functional defect.
• Ventricular mural thrombi sometimes develop,