Myocarditis (Complete*)

Question 1

Define myocarditis

Answer 1

Inflammation of the myocardium

Question 2

Myocarditis in conjunction with pericarditis is known as?

Answer 2

Myopericarditis

Question 3

What are the three main types of myocarditis based onset and severity?

Answer 3

Fulminant myocarditis: Presence of cardiogenic shock

Acute myocarditis: Less than 1 month

Chronic myocarditis: More than 1 month

Question 4

What is the most common cause of myocarditis in the UK and EU?

Answer 4

Cocksackie B virus

Question 5

What is the worldwide most common cause of myocarditis?

Answer 5

Chagas disease (Trypanosoma cruzi)

Question 6

What antipsychotic can cause myocarditis?

Answer 6

Clozapine

Question 7

Give examples of causes of myocarditis

Answer 7

Infections:

• Cocksackie B virus
• Covid
• Adenovirus
• EBV
• Diphtheria
• Clostridia
• Neiseria gonorrhoea
• Chagas disease

Auto-immune:

• Kawasakis disease
• SLE
• Sarcoidosis
• Scleroderma
• Systemic vasculitis

Drugs:

• Antipsychotics (e.g. clozapine)
• Lithium
• Amphetamines
• Immune-checkpoint inhibitors
• Mesalazine

Question 8

What antipsychotic is most associated with myocarditis?

Answer 8

Clozapine

Question 9

What risk factors are associated with myocarditis? (5)

Answer 9

Age < 50 years

Previous or recent infection

HIV

Autoimmune conditions (e.g. SLE)

Pregnancy (peri-natal or post-natal)

Question 10

What are the main signs/symptoms of myocarditis? (6)

Answer 10

Viral prodrome 2-3 weeks prior to cardiac symptoms is common

Systemic upset

• Fever
• Fatigue/lethargy

Chest pain (plueritic or cardiac-like)

• Sharp/stabbing
• Cardiac type in some cases (e.g. retrosternal pressure)
• Pleuritic (if pericardial involvement)

Palpitations/arrythmias

Fulminant myocarditis

Dyspnoea

Syncope

Symptoms of heart failure (e.g. orthopnoea)

Usually presents in young patients

N.B. Suspect in young patient with cardiac-type chest pain with viral prodrome +/- palpiations or pericardial involvement

Question 11

What characteristic of chest pain in myocarditis is suggestive of additional pericardial involvement?

Answer 11

Pain worse when lying down

Pleuritic

N.B. Lying down causes gravity to push heart onto inflammed posterior pericardium hence worsening pain

Question 12

What findings on examination can present in patients with myocarditis? (3)

Answer 12

Dull heart sounds

Signs of heart failure (if fulminant myocarditis)

Pericardial friction rub (If myopericarditis)

Often examination findings are non-specific

Question 13

What additional clinical signs are suggestive of fulminant myocarditis?

Answer 13

Signs of HF (e.g. raised JVP, S3 gallop)

Question 14

What are complications of myocarditis?

Answer 14

Sudden cardiac death

Arrythmias

DCM

Heart failure

Question 15

What differentials should be considered alongside myocarditis?

Answer 15

ACS

• Crushing central chest pain versus sharp stabbing and generalised
• Up-trending troponin

Pericarditis

• Chest pain is more pleuritic and positional
• Less likely to be febrile (unless fulminant pericarditis)
• Normal troponins + PR deppresion or saddle-shaped ST elevations

PE

• Sudden-onset pleuritic chest pain
• Desaturations
• Risk factors for PE (e.g. DVT, long-haul travel, OCP)

Question 16

What investigations should be ordered in patients suspected of having myocarditis? (5)

Answer 16

Bedside:

ECG

• Non specific ST elevation and T wave inversion changes

Bloods:

Troponin: Raised

FBC: Check for anaemia or sepsis

ESR: Raised

CRP: Raised

BNP: Raised if HF

Autoimmune screen

Imaging:

CXR

• May show signs of HF or cardiomegaly (suggestive of pericardial effusion)

Transthoracic echo

• Rule out valvular disease which can mimic myocarditis

Cardiac MRI

• Show inflammation

Endomyocardial biopsy

Question 17

What ECG findings may be seen in patients with myocarditis?

Answer 17

Non-specific ST changes and T wave changes

Arrythmias

Tacchycardias

Ventricular ectopics

Question 18

What blood test findings support a diagnosis of myocarditis? (3)

Answer 18

ESR: Raised

CRP: Raised

Troponin: Markedly raised

BNP: Raised

Question 19

What is the non-invasive diagnostic investigation of choice in most cases of myocarditis?

Answer 19

Cardiac MRI

Question 20

What is the gold-standard diagnostic tool for myocarditis?

Answer 20

Endomyocardial biopsy via cardiac catheterisation (However is inavsive and has own risks)

Question 21

What histological findings confirm a diagnosis of myocarditis?

Answer 21

Inflammatory infiltrates with myocyte degeneration and necrosis of non-ischaemic origin

Question 22

When is endomyocardial biopsy indicated?

Answer 22

Only if high-risk presentations such as:

Cardiogenic shock

Acute heart failure requiring inotropic or mechanical support

Ventricular arrhythmias

Mobitz type II atrioventricular block or higher

Ventricular ectopic

N.B. Can consider if it can confirm an underlying diagnosiss which can aid management (e.g. autoimmune)

Question 23

What is the management plan for patients with myocarditis?

Answer 23

Discussion with cardiac intensive care unit for early escalation if demonstrating signs of cardiogenic shock

Conservative:

Supportive management:

• Treat complications of HF or arrythmia

Lifestyle support: Limit activity for at least 3-6 months

Medicine: Treat underlying cause

Viral myocarditis: Corticosteroids

Bacterial myocarditis: Antibiotics

Autoimmune myocarditis: Immunosupressants

Pericardial involvement: NSAIDs or colchicine

Question 24

What medication is reccomended for patients with viral myocarditis?

Answer 24

Corticosteroids

Question 25

Which patients should be escalated to cardiac ICU?

Answer 25

Patients with cardiogenic shock ## Footnote N.B. Important to liase with ICU team for all patients with myocarditis in case they rapidly deteriorate

Question 26

How are patients with cardiogenic shock managed?

Answer 26

May need vassopresors/inotropes or mechanical cardiac support.

Question 27

What lifestyle advice should be given to patients with myocarditis?

Answer 27

Should avoid strenuous exercise for **3-6 months**

Question 28

How should patients with myocarditis be followed up in primary care?

Answer 28

Should be followed up regularly to assess for HF May need serial echograms to assess myocardial recovery

Question 29

What complications can arise in patients with myocarditis? (4)

Answer 29

Sudden cardiac death Arrythmia (which can lead to sudden cardiac death) Heart failure Dilated cardiomyopathy (late complication)