Cardiomyopathy & Endocarditis

Question 1

State at least 4 causes of dilated cardiomyopathy

Answer 1

Idiopathic, alcohol, peripartum, genetic, sarcoidosis, haemochromatosis, myocarditis

Question 2

State 2 causes of hypertrophic cardiomyopathy

Answer 2

Genetic, storage diseases

Question 3

State 3 causes of restrictive cardiomyopathy

Answer 3

Sarcoidosis, amyloidosis, radiation-induced fibrosis

Question 4

Describe the histological appearance of hypertrophic cardiomyopathy

Answer 4

Myocyte disarray

Question 5

What is the inheritance pattern of genetic hypertrophic cardiomyopathy?

Answer 5

Autosomal dominant

Question 6

What is the most common gene mutation causing hypertrophic cardiomyopathy? State at least one other

Answer 6

BetaMHC gene mutation (403 Arginine -> glutamine)

Others: MYBP-C mutation, Troponin-T mutation

Question 7

Which mutation has the highest risk of sudden cardiac death?

Answer 7

Troponin T mutation

Question 8

What is hypertrophic obstructive cardiomyopathy (HOCM)?

Answer 8

Septal hypertrophy resulting in outflow tract obstruction

Question 9

What percentage of hypertrophic cardiomyopathy progresses to dilated cardiomyopathy?

Answer 9

15-20%

Question 10

What is arrhythmogenic right ventricular cardiomyopathy (ARVC)?

Answer 10

Myocyte loss with fibrofatty replacement affecting the right ventricle

Question 11

Between what ages is rheumatic fever most common?

Answer 11

5-15 years

Question 12

Describe the symptoms of rheumatic fever

Answer 12

Pancarditis (endocarditis, myocarditis, pericarditis), arthritis, synovitis, erythema marginatum, subcutaneous nodules, encephalopathy, Sydenham’s chorea

Question 13

How is rheumatic fever diagnosed?

Answer 13

Evidence of group A strep infection + 2 Major or 1 Major + 2 Minor Jones criteria

Question 14

State Jones’ major criteria for diagnosing rheumatic fever

Answer 14

CASES: Carditis, Arthritis, Sydenham’s chorea, Erythema marginatum, Subcutaneous nodules

Question 15

State Jones’ minor criteria for diagnosing rheumatic fever

Answer 15

Fever, raised ESR/CRP, migratory arthralgia, prolonged PR interval, previous rheumatic fever, malaise, tachycardia

Question 16

Which valve is most commonly affected by rheumatic fever?

Answer 16

Mitral (affected alone in 70%, with aortic in 25%)

Question 17

What is the main causative pathogen of rheumatic fever?

Answer 17

Lancefield group A strep (Streptococcus pyogenes)

Question 18

How is rheumatic fever treated?

Answer 18

Benzylpenicillin

Erythromycin if allergic to penicillin

Question 19

Describe the pathogenesis of rheumatic fever

Answer 19

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.

Question 20

Describe the histological appearance of the heart during acute rheumatic fever

Answer 20

Beady fibrous vegetations, Aschoff bodies (small giant cell granulomas), Anitschkov myocytes (regenerating myocytes)

Question 21

Describe the vegetations caused by rheumatic heart disease

Answer 21

Verrucae: Small, warty vegetations found along the lines of closure of the leaflet valve

Question 22

Describe the vegetations caused by infective endocarditis

Answer 22

Large, irregular masses on valve cusps, extending into the chordae

Question 23

Describe the vegetations caused by marantic endocarditis (non-bacterial thrombotic endocarditis)

Answer 23

Small, bland vegetations attached to lines of closure, formed by thrombi

Question 24

State a caused of marantic endocarditis (non-bacterial thrombotic endocarditis)

Answer 24

Disseminated intravascular coagulation, other hypercoagulable states

Question 25

Describe the vegetations caused by Libman-Sacks endocarditis

Answer 25

Small (up to 2mm), warty, sterile vegetations rich in platelets

Question 26

Name two conditions associated with Libman-Sacks endocarditis

Answer 26

SLE, anti-phospholipid syndrome