Myocarditis

Question 1

What is myocarditis?

Answer 1

Inflammation of the myocardium

Associated with pericardial inflammation (myopericarditis)

Question 2

What are the causes of myocarditis?

Answer 2

Idiopathic - 50% of casees

Viral (most commonly Coxsackie but also adenovirus, parvovirus B19, enteroviruses, HIV, EBV, Hep A&C)

Bacterial (e.g., Chlamydia pneumophila)

Spirochaetes

Protozoa (esp Chagas)

Drugs (e.g., clozapine, acetazolamide, amitriptyline, penicillin, methyldopa, phenytoin etc.)

Toxins

Immunological (e.g., SLE, sarcoidosis, Churg-Strauss, IBD, Kawasaki, T1DM, Myasthenia gravis, polymyositis etc)

Question 3

List the viral causes of myocarditis

Answer 3

• Coxsackie (most common in USA + Europe)
• enteroviruses
• adenoviruses
• HHV6
• EBV
• CMV
• influenza
• hepatitis
• mumps
• rubella
• polio
• HIV
• HSV

Question 4

List the bacterial causes of myocarditis

Answer 4

• Staph
• Strep
• Clostridia
• diphtheria
• TB
• meningooccus
• Mycoplasma
• brucellosis
• psittacosis

Question 5

List the Spirochaetes causes of myocarditis

Answer 5

• Leptospirosis
• syphillis
• Lyme disease

Question 6

List the drugs that can cause myocarditis

Answer 6

• cyclophosphamide
• trastuzumab
• penicillin
• chloramphenicol
• sulfonamides
• methyldopa
• spironolactone
• phenytoin
• carbamazepine

Question 7

List the protozoa causes of myocarditis

Answer 7

• Chagas’
• Leishmania
• toxoplasmosis

Question 8

List the toxins that can cause myocarditis

Answer 8

• cocaine
• lithium
• alcohol
• lead
• arsenic

Question 9

List the immunological causes of myocarditis

Answer 9

• SLE
• sarcoid
• Kawasaki
• scleroderma
• heart transplant rejection

Question 10

What are the symptoms and signs of myocarditis?

Answer 10

ACS-like symptoms - chest pain, dyspnoea etc

HF symptoms

Palpitations

Tachycardia

Soft S1

S4 gallop

Question 11

What are the ECG findings of myocarditis?

Answer 11

ST changes

T-wave inversion

Atrial arrhythmias

Transient AV block

QT prolongation

Question 12

What investigations would you do for suspected myocarditis?

Answer 12

ECG

Bloods
- CRP/ESR - may be raised
- troponin - may be raised
- viral serology

Echo
- diastolic dysfunction
- regional wall abnormalities

Cardiac MR
- if clinically stable

Endomyocardial biopsy = gold standard

Question 13

What is the treatment/Mx of myocarditis?

Answer 13

Supportive - treat underlying cause

Treat arrhythmia and HF

Avoid exercise - can precipitate arrhythmias

Need to admit the patient

Question 14

What is the prognosis of myocarditis?

Answer 14

50% recover within 4 weeks

12-25% will develop DCM + severe HF

DCM can occur years after apparent recovery

Question 15

Sources

Answer 15

pg 152-153 Oxford Handbook of Clinical Medicine 10th edition

https://www.bhf.org.uk/informationsupport/conditions/myocarditis

https://patient.info/doctor/myocarditis-pro#nav-3