B P6 C55 Myocarditis Flashcards
(121 cards)
_____ refers to inflammation of the heart muscle occurring as a result of exposure to either discrete external antigens, such as viruses, bacteria, parasites, toxins, or drugs, or internal triggers, such as autoimmune activation against self-antigens.
Classic myocarditis
Although _____ remains the most commonly identified cause of myocarditis, drug hypersensitivity and toxic drug reactions, other infections, and peripartum cardiomyopathy also can lead to myocarditis.
Viral infection
The pathogenesis of myocarditis is a classic paradigm of cardiac injury followed by _____ response from the host resulting in cardiac inflammation.
Immunologic
Indeed, more than 20 viruses have been associated with myocarditis, and the most frequent are currently _____.
Parvovirus B19 (B19V)
HHV-6
If the host immune response is overwhelming or inappropriate, the inflammation may destroy the heart tissue acutely or may linger, producing cardiac remodeling that leads to _____.
DCM
HF
Death
Disability from myocarditis is largely due to _____.
Heart Failure
The death rate from myocarditis is higher in the _____ year of life than between ages 1 and 14 years for both males and females.
After age 15 years, DALYs, number of deaths, and death rate due to myocarditis are higher in males than females.
1st year of life
After age 15: M>F
Myocarditis is responsible for sudden cardiovascular death in approximately ___% of infants, ___% of children, and ___% of young athletes
2% - Infants
5% - Children
5-14% Young athletes
The standard Dallas criteria define idiopathic myocarditis as an _____.
Inflammatory infiltrate of the myocardium
+
Necrosis and/or degeneration of adjacent myocytes not typical of the ischemic damage associated with coronary artery disease
The presence of viral genomes in heart tissue may indicate an active infectious myocarditis.
In the posttransplantation setting, the presence of viral genomes in myocardial biopsy material predicts future _____ in children
Rejection episodes and graft loss
In most cases, myocarditis is triggered by an inciting event, such as _____ that activates the immune response
Infection
or
Exposure to a drug or toxin
_____ has been implicated as one of the most common infectious causes of myocarditis
Viral infection
Modern virologic and molecular techniques have demonstrated that _____ are among the most commonly identified infectious agents in myocarditis.
Adenoviruses
Parvovirus
Enteroviruses
Endomyocardial Biopsy Diagnosis of Myocarditis: The Dallas Criteria Definition
Idiopathic myocarditis: “an inflammatory infiltrate of the myocardium with necrosis and/or degeneration of adjacent myocytes not typical of the ischemic damage associated with coronary artery disease”
Endomyocardial Biopsy Diagnosis of Myocarditis: The Dallas Criteria Classification
*First biopsy
Myocarditis with or without fibrosis
Borderline myocarditis (repeat biopsy may be indicated)
No myocarditis
*Subsequent biopsy
Ongoing (persistent) myocarditis +/- fibrosis
Resolving (healing) myocarditis +/- fibrosis
Resolved (healed) myocarditis +/- fibrosis
Possible subclinical acute myocarditis criteria
In the clinical context of possible myocardial injury WITHOUT cardiovascular symptoms but with at least one of the following:
Biomarkers of cardiac injury raised
ECG findings suggestive of cardiac injury
Abnormal cardiac function on echocardiogram or CMR
Probable acute myocarditis criteria
In clinical context of possible myocardial injury WITH cardiovascular symptoms and at least one of the following:
Biomarkers of cardiac injury raised
ECG findings suggestive of cardiac injury
Abnormal cardiac function on echocardiogram or CMR
Definite myocarditis criteria
Histologic or immunohistologic evidence of myocarditis
_____ virus infection appears to be mainly associated with cardiomyopathy in Asian countries such as Japan
Hepatitis C
Frequent causes of myocarditis
Adenovirus
Coxsackievirus
Cytomegalovirus
Anthracyclines
Cocaine
Alcohol
As the world has turned its attention to the COVID-19 pandemic, it became clear during the early stages of the disease that patients who were admitted to the hospital for COVID-19 had a ____% incidence of myocardial injury manifested by an increase in troponin and type B natriuretic factor
20-35%
The pathogenesis of cardiac injury in COVID-19 is complex with mechanisms that include _____.
Viral mediated injury
Microvascular dysfunction/ thrombosis
Cytokines
Type II myocardial infarctions
It was assumed initially that this myocardial injury was secondary to a _____ form of myocarditis precipitated by infection of cardiac cells by SARS-CoV-2.
Classical form
The histological features seen at autopsy include _____.
Classic lymphocytic myocarditis is relatively uncommon in COVID-19 patients.
Increased macrophages and cytokine elevation