MYOCARDIAL AND PERICARDIAL DISEASES Flashcards
What is myocarditis?
Inflammation of the myocardium
What can cause myocarditis?
viral: adenovirus, influenza A and B, coxsackie B, HIV, EBV, hep B and C
bacteria: diphtheria, clostridia
spirochaetes: Lyme disease
protozoa: Chagas’ disease, toxoplasmosis
autoimmune e.g. SLE, polymyositis, sarcoidosis
drugs: doxorubicin, clozapine, cocaine
How does myocarditis present?
May have a viral prodrome 2-3 weeks e.g. fevers, myalgia, URTI
Chest pain that can be positional
Palpitations and syncope
Dyspnoea and orthopnoea
Fever and fatigue may also occur
In severe cases, fluid retention may occur (i.e. when it progresses to heart failure)
Tachycardia
S3 and S4
Who does myocarditis typically affect?
All age groups can be affected but commonly affects those <50
How do you investigate myocarditis?
Bloods - raised inflammatory markers, troponin and BNP
ECG
CXR - cardiomegaly or HF signs
Echocardiogram - ventricular dilatation and abnormal wall movement
Endomyocardial biopsy is gold standard (not often done as risky)
Cardiac MRI (to differentiate between MI)
What are ECG changes associated with myocarditis?
Sinus tachycardia
Ventricular arrhythmias
ST segment changes e.g. ST segment elevation or depression
T wave inversion
QT prolongation
AV block
How is myocarditis managed?
Identify and treat underlying cause e.g. antibiotics if bacterial cause
supportive treatment e.g. of heart failure or arrhythmias
Exercise limitation
Alcohol restriction
Supportive care
Treat arrhythmias and HF
No evidence for immunosuppressive therapy unless underlyign systemic autoimmune disease
No evidence for NSAIDs
Heart transplant or left ventricular assist device if refractory/end-stage
What are complications of myocarditis?
heart failure
arrhythmia, possibly leading to sudden death
dilated cardiomyopathy: usually a late complication
Pericarditis
Thromboembolism
Sudden cardiac death
Whats the most common cause of myocarditis?
In 50% of cases its idiopathic but the most implicated Etiology in pt with an identified cause is a viral infection
Outline the pathophysiology of myocarditis?
Entry of virus into myocardial cells -> myocardial cell damage and death -> release of cellular contents -> activation of inflammatory response -> further damage and inflammation
chronic inflammation and remodelling of the myocardium in chronic cases can cause myocardial dilation and cardiomyopathy
Whats gold standard for diagnosing myocarditis?
Endomyocardial biopsy
why is endomyocardial biopsy not often done?
Risks of perforation with pericardial tamponade, pneumothorax, puncture of central arteries, PE, heart block, tachyarrythmias, nerve paresis, venous hematoma, damage to tricuspid balance, creation of arterial venous fistula, infection, bleeding, allergic reaction
What is giant cell myocarditis?
A rare and severe type characterised by the presence of multi nucleated giant cells in the heart muscle
Cause is unknown byt may be associated with autoimmune diseases
Often associated with rapid and progressive heart failure so has a poor prognosis
Immunosuppression is recommended
What is Eosinophilic myocarditis?
Rare type characterised by infiltration of heart muscle with eosinophils
Causes include parasitic infections, drug reactions and allergic reactions
What is granulomatoius myocarditis?
This type of myocarditis is characterized by the presence of granulomas in the heart muscle. Granulomatous myocarditis can be caused by various infectious agents, such as fungi and mycobacteria, as well as non-infectious causes, such as sarcoidosis.
What is fulminant myocarditis?
a severe form of myocarditis characterized by the sudden onset of symptoms and rapid deterioration of cardiac function. It is a rare but life-threatening condition that can lead to cardiogenic shock, multiorgan failure, and death if left untreated
Typically caused by a viral infection
What is a cardiac myxoma?
A rare, benign mesenchymal cardiac tumour that arises from primitive cells in the heart (benign but if it grows too large it can affect the heart function)
Most occur sporadically but some are part of some familial syndromes
Most commonly found in the left atrium
How does a cardiac myxoma present?
Symptoms vary dependant on location and size of tumour
May be fatigue, fever, chest pain, dyspnoea, palpitations, syncope, weight loss and embolic events
What is a rhabdomyoma?
A benign hamartomatous tumour of striated muscle
Can be cardiac or extra cardiac
The most common primary tumour of the heart in infants and children
Often asymptomatic
What conditions is myxoma associated with?
Carney complex
Familial myxomatous syndrome
What conditions is rhabdomyoma associated with?
Tuberous sclerosis
What is pericarditis?
Inflammation of the pericardium (visceral and parietal layers)
Outline the epidemiology of pericarditis?
More common in men
Affects young adults
What is perimyocarditis?
inflammation of both the pericardial sac and myocardium with a primarily myocarditic syndrome
What is myopericarditis?
inflammation of both pericardial sac and myocardium with a primarily pericarditic syndrome
How is acute and chronic pericarditis differentiated?
Acute - <6 weeks
Chronic - lasts >6 weeks
Outline the anatomy of the pericardium?
Parietal pericardium: internal surface of the fibrous pericardium
Visceral pericardium: inner membrane, known as the ‘epicardium’, which covers the heart and great vessels
Pericardial space: contains a small amount of serous fluid (20-50 mls)
Total thickness is 1-2mm
What are the 3 main physiological functions of the pericardium?
Mechanical - limits cardiac dilation, maintains ventricular compliance and aids atrial filling
Barrier - reduces external friction and acts as a barrier
Anatomical - fixes the heart through its ligamentous function
What are causes of pericarditis?
Idiopathic
Viral - often due to Coxsackievirus B but others include influenza, echovirus, adenovirus
Bacterial
TB
Fungal
Post-myocardial infarction e.g. fibrinous pericarditis or dressler syndrome
Radiotherapy
Hypothyroidism
Maliganncy - lung or breast cancer
Trauma
Systemic inflammatory diseases e.g. RA or SLE
Uraemia
Whats the most common cause of acute pericarditis?
Idiopathic
How does pericarditis present?
Chest pain - pleuritic, sharp, exacerbated by movement and relieved by sitting forward
Low grade fever
Non-productive cough
SOB (may indicate pericardial effusion or myocardial involvement)
What are signs of pericarditis?
Pericardial friction rub: scratchy or squeaking sound heard over the heart
Features of cardiac tamponade: muffled heart sounds, distended JVP, pulsus paradoxus, hypotension
Tripod position
What is pulses paradoxus?
A fall in bp >10mmHg during inspiration
What is Dressler’s syndrome?
a specific autoimmune form of acute pericarditis that occurs 2-3 weeks following a myocardial infarction - autoimmune reaction to myocardial antigens post infarction
What are the 2 ways which MI can lead to pericarditis?
early (1-3 days): fibrinous pericarditis
late (weeks to months): autoimmune pericarditis (Dressler’s syndrome)
How is pericarditis investigated?
Bloods - FBC, U&Es, CRP, ESR, troponin (may do others dependant on suspected aetiology e.,g. Virology, cultures or autoimmune screen)
ECG
?CXR to exclude alternative diagnosis
Transthoracic echocardiogram
What are ECG changes seen in pericarditis?
Global changes as opposites to the territories as seen in ischaemic events:
Saddle-shaped ST-elevation
PR depression (most specific ECG marker!)
What does a raised troponin alongside pericarditis suggest?
Suggests myocardial involvement i.e. myopericarditis
How is pericarditis managed?
NSAIDs 1-2 weeks until pain resolved (with PPI)
Colchicine for 3 months to reduce the risk of recurrence
(If fail to respond then oral corticosteroids can be used)
Pericardiocentesis may be required if significant/symptomatic pericardial effusion or tamponade
Treat the cause!
Whats the prognosis of pericarditis?
Up to 30% of pt without treatment will develop recurrent disease
Good long term prognosis with most cases resolving in 1 month
What are complications of acute pericarditis?
Chronic pericarditis
Pericardial effusion which can become cardiac tamponade
Recurrent pericarditis
Constrictive pericarditis
Chronic HF
All rare!
What is pericardial effusion?
Accumulation of excess fluid within the pericardial cavity
This can put pressure on the heart, comprising heart function as it leads to reduced filling of the heart during diastole
How do NSAIDs work for pericarditis?
They provide symptomatic relief by reducing inflammation via COX-1 inhibition
How does colchicine work for pericarditis?
Inhibits tubulin polymerisation thereby inhibiting mitotic activity in cells = reducing inflammation
What is cardiac tamponade?
where the pericardial effusion is large enough to raise the intra-pericardial pressure. This increased pressure squeezes the heart and affects its ability to function. It leads to reduced filling of the heart during diastole, resulting in decreased cardiac output during systole. This is an emergency requiring rapid drainage of the pericardial effusion to relieve the pressure.
What can a pericardial effusion be made of?
Transudates (low protein content)
Exudates (associated with inflammation)
Blood
Pus
Gas (associated with bacterial infections)
What can cause a transudative pericardial effusion?
Increased venous pressure can reduce drainage from the pericardial cavity e.g. congestive HF or pulmonary hypertension
What can cause a exudative pericardial effusion?
Inflammatory processes e.g. infections, autoimmune conditions, injury to pericardium (MI, open heart surgery, trauma), uraemia, cancer or medications such as methotrexate
What can cause a rapid-onset pericardial effusion?
Rupture of the heart or aorta causing bleeding into the pericardial cavity e.g. MI, trauma or type A aortic dissection
How does a pericardial effusion present?
May be asymptomatic initially
Chest pain
Shortness of breath
A feeling of fullness in the chest
Orthopnoea
Or it may occur suddenly with haemodynamic compromise and collapse
Hiccups (if phrenic nerve compression)
Dysphagia (if oesophageal compression)
Hoarse voice (if recurrent laryngeal nerve compression)
How is a pericardial effusion diagnosed?
Echo
Pericardial fluid analysis - protein content, bacterial culture, viral PCR< cytology and tumour markers
How do we manage pericardial effusion?
Treat underlying cause
Pericarditis management with NSAIDs and colchicine
Draining effusion
Pericardiectomy - rare and usually only done in recurrent cases
What are the 2 options for pericardial fluid drainage?
Needle pericardiocentesis (echocardiogram guided)
Surgical drainage
What causes chronic pericarditis?
Almost any cause of acute pericarditis but typically bacterial or TB pericarditis
Outline the pathophysiology of chronic pericarditis?
Chronic inflammation leads to scarring and loss of the normal fibroelastic pericardial tissue. This can impede normal cardiac filling leading to features of right heart failure
What are the 3 clinical phenotypes of constrictive pericarditis?
Transient constriction: reversible constriction with resolution spontaneously or with medical therapy
Effusion-constriction: constrictive pericarditis with evidence of a pericardial effusion (features of constriction persist even after removal of pericardial fluid)
Chronic constriction: constriction > 3-6 months duration
Outline the spectrum of pericardial disease following an episode of acute pericarditis?
Acute pericarditis
Pericardial effusion
Chronic effusive pericarditis
Effusive-constrictive pericarditis
Chronic constrictive pericarditis
How does chronic pericarditis present?
HF symptoms and signs
How is chronic pericarditis managed?
Specialist management but a pericardiectomy is considered
How much fluid does the pericardial sac usually contain?
20-50ml
What can cause cardiac tamponade?
Pericarditis
Tuberculosis
Iatrogenic (e.g. post invasive cardiac procedure)
Trauma
Malignancy
Uncommon - connective tissue disease, radiation, uraemia, post-MI, aortic dissection, bacterial infection
Outline the pathophysiology of cardiac tamponade?
The pericardial sac has a degree of elasticity but as an effusion increases in size, there is increased pressure that starts to compress all four chambers of the heart. As pressure increases, the chambers become smaller in size and there is decreased diastolic compliance. Cardiac tamponade reduces venous return that restricts ventricular filling and this leads to a reduction in stroke volume and cardiac output. The end result is a decrease in blood pressure and haemodynamic compromise.
Why does cardiac tamponade cause pulsus paradoxus?
During inspiration, venous return normally increases to the right side of the heart and pulmonary venous return decreases to the left side of the heart. When the heart is compressed in tamponade, only the interventricular septum distends partially on inspiration. This septum bulges into the left ventricle, further impeding ventricular filling and results in a greater fall in blood pressure.
How does cardiac tamponade present?
Carcinogenic shock
Cardiac arrest
If subacute presentation then dyspnoea, chest pain, peripheral oedema, syncope, fatigue
What are the signs of cardiac tamponade?
Beck’s triad - hypotension, elevated venous pressure and muffled heart sounds
Pulsus paradoxus
Features of shock
Tachycardia
Pericardial rub if pericarditis
How is cardiac tamponade diagnosed?
Echo
ECG
CXR
What are Echo features of cardiac tamponade?
Early diastolic collapse of right ventricle and late diastolic collapse of right atrium
Respiratory variation in volume ands flow
Features of elevated venous pressure e.g. Dilatation of IVC and <50% reduction in diameter during inspiration
How is cardiac tamponade managed?
Urgent drainage of pericardial fluid - usually via pericardiocentesis (surgery is an alternative option)
What is constrictive pericarditis?
Thickened, fibrotic, stiff pericardium that limits the heart’s ability to function normally = SV reduces
How is constrictive pericarditis different from cardiac tamponade?
Develops more slowly than cardiac tamponade
Result of change in composition of serous pericardium rather than a fluid collection around the serous pericardium
How does constrictive pericarditis present?
Fever
Chest pain that worsens with deep breathing and improves with sitting up and leaning forward
Muffled heart sounds and pericardial knock
SOB
Hypotension and pre-syncope, fatigue and reflex tachycardia
Right HF
AF due to atrial dilation
How can pericardial effusions affect ECG?
Low voltage QRS complexes
Electrical alternans - QRS complexes have different heights
What does pericardial effusion look like on CXR?
Water bottle sign - enlargement of the cardiac silhouette
What would you seen on echo in Pericardial effusion?
Heart would look like its dancing within the pericardium
What would you seen on echo in constrictive pericarditis?
Stiff, serous pericardium restricting the heart’s movement
Why is pericarditis pain relieved by standing/leaning forward?
As diaphragm is not pushing on the heart
Why is pericarditis pain pleuritic?
On inspiration, lungs expand which compresses the heart and the inflamed pericardium
