Myocarditis

Question 1

Myocarditis

Answer 1

Inflammatory cardiac disease of the myocardium and beyond

Increased in young males

Question 2

Etiology V/B/F/P

Answer 2

Virus- enteroV coxBV parainfluenza influenza varicella poliomyelitis EBV adenoV
Bacteria- rickettsiae diphtheria N. Meningitis M. tuberculosis Beta hemolytic strep
Fungi- candida aspergillus
Parasites- Chagas’ disease (T. Cruzi) toxoplasmosis (leads to chronic immune mediated MC and cardiac insufficiency)

Question 3

Etiology toxins/other

Answer 3

Toxins- alcohol cocaine heavy metals drugs botulism
Other- idiopathic Giant cell MC SLE DM thyrotoxicosis physical injury radiation post transplant helminths chlamidya sarcoidosis amyloidosis

Question 4

Pathophysiology

Answer 4

MC causes myocardial inflammation/injury/necrosis/fibrosis

Resulting in myocardial damage cardiac enlargement reduced systolic function

Question 5

Pathophysiology v-MC

Answer 5

Acute v-MC to Chronic
Persistence of viral nucleic acids in myocardium
CI altered host response +TL/BL leads to AB mediated cell damage and dilated cardiomyopathy

Question 6

Clinical course

Answer 6

Acute <3 months myocyte necrosis and Mac activation (IL-1/2 TNF IFN)
Subacute <12 months infiltrating mononuclear cells (TL/BL/NK cells > NO/perforins)
Chronic >12 months fibrosis HF cardiac dilation

Question 7

Severity and activity of process

Answer 7

Mild moderate severe

0 1 2 3

Question 8

Clinical manifestations

Answer 8

General- SCD HF arrhythmia
Infants - acute and fulminant v-MC
Children- acute myopericarditis
Adolescent- asymptomatic and precursor for idiopathic dilated cardiomyopathy

Question 9

Histology MC

Answer 9

Normal or enlarged heart
Ventricular myocardium flabby/mottled/dark red due to Hm foci
(Late stages)

Question 10

Dallas criteria

Answer 10

No longer used
Diagnostic in 10-20% P
Too many interpretation and sampling errors
L infiltrate with myocyte degeneration and necrosis ++
L infiltrate without myocyte degeneration and necrosis borderline MC
L infiltrate without PC/Mac/N/E not ass. To HS-MC

Question 11

Endomyocardial biopsy

Answer 11

Gold standard in diagnosis of MC
Early procedure= better results
Used in P with progressive or unexplained cardiomyopathy/ventricular arrhythmia/conduction system disturbances

Question 12

MC DD

Answer 12

Sarcoidosis catecholamine toxicity

Question 13

Giant cell MC

Answer 13

Rare idiopathic CVD 
Disease of young healthy people 
Mortality ass. To HF/VA
Usually requires heart transplant
Disease can recur

Question 14

Giant cell MC histology

Answer 14

Mixed inflammatory infiltrate (Mac/L/PC/E/MGC)
Focal or extensive necrosis
@active phase GC are adjacent to necrotic myocytes
NO granuloma

Question 15

Giant cell MC DD

Answer 15

HS MC and sarcoidosis