Cardiomyopathy & Endocarditis Flashcards
State at least 4 causes of dilated cardiomyopathy
Idiopathic, alcohol, peripartum, genetic, sarcoidosis, haemochromatosis, myocarditis
State 2 causes of hypertrophic cardiomyopathy
Genetic, storage diseases
State 3 causes of restrictive cardiomyopathy
Sarcoidosis, amyloidosis, radiation-induced fibrosis
Describe the histological appearance of hypertrophic cardiomyopathy
Myocyte disarray
What is the inheritance pattern of genetic hypertrophic cardiomyopathy?
Autosomal dominant
What is the most common gene mutation causing hypertrophic cardiomyopathy? State at least one other
BetaMHC gene mutation (403 Arginine -> glutamine)
Others: MYBP-C mutation, Troponin-T mutation
Which mutation has the highest risk of sudden cardiac death?
Troponin T mutation
What is hypertrophic obstructive cardiomyopathy (HOCM)?
Septal hypertrophy resulting in outflow tract obstruction
What percentage of hypertrophic cardiomyopathy progresses to dilated cardiomyopathy?
15-20%
What is arrhythmogenic right ventricular cardiomyopathy (ARVC)?
Myocyte loss with fibrofatty replacement affecting the right ventricle
Between what ages is rheumatic fever most common?
5-15 years
Describe the symptoms of rheumatic fever
Pancarditis (endocarditis, myocarditis, pericarditis), arthritis, synovitis, erythema marginatum, subcutaneous nodules, encephalopathy, Sydenham’s chorea
How is rheumatic fever diagnosed?
Evidence of group A strep infection + 2 Major or 1 Major + 2 Minor Jones criteria
State Jones’ major criteria for diagnosing rheumatic fever
CASES: Carditis, Arthritis, Sydenham’s chorea, Erythema marginatum, Subcutaneous nodules
State Jones’ minor criteria for diagnosing rheumatic fever
Fever, raised ESR/CRP, migratory arthralgia, prolonged PR interval, previous rheumatic fever, malaise, tachycardia
Which valve is most commonly affected by rheumatic fever?
Mitral (affected alone in 70%, with aortic in 25%)
What is the main causative pathogen of rheumatic fever?
Lancefield group A strep (Streptococcus pyogenes)
How is rheumatic fever treated?
Benzylpenicillin
Erythromycin if allergic to penicillin
Describe the pathogenesis of rheumatic fever
The body produces antibodies against group A strep infection. These antibodies and cell-mediated immunity cross-reaction with myocardial antigens (antigenic mimicry) leading to pancarditis.
Describe the histological appearance of the heart during acute rheumatic fever
Beady fibrous vegetations, Aschoff bodies (small giant cell granulomas), Anitschkov myocytes (regenerating myocytes)
Describe the vegetations caused by rheumatic heart disease
Verrucae: Small, warty vegetations found along the lines of closure of the leaflet valve
Describe the vegetations caused by infective endocarditis
Large, irregular masses on valve cusps, extending into the chordae
Describe the vegetations caused by marantic endocarditis (non-bacterial thrombotic endocarditis)
Small, bland vegetations attached to lines of closure, formed by thrombi
State a caused of marantic endocarditis (non-bacterial thrombotic endocarditis)
Disseminated intravascular coagulation, other hypercoagulable states
