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The heart is covered in two layers of pericardium:
The outer fibrous pericardium is attached to the central tendon of the diaphragm.
The serous pericardium is split into an inner visceral layer and outer pericardial layer.
Between these layers, there is a space which contains 15–50 mL of pericardial fluid.
Acute pericarditis
This refers to acute inflammation of the pericardium, which surrounds the cardiac muscle.
Causes
Infections – TB is one of the most common causes worldwide. Viral infections (Coxsackie)
Autoimmune – SLE, rheumatoid arthritis etc.
Metabolic – anorexia, hypothyroidism, uraemia (causes “fibrinous” pericarditis)
Cardiac – post-MI, Dressler’s syndrome
Symptoms
Central chest pain, can be pleuritic in nature
Pain worse on lying flat and often relieved by sitting forward
Shortness of breath, may have a non-productive cough and low-grade fever
Key tests
ECG – global saddle shape ST segment elevation and PR segment depression
CXR – this is needed to rule out other causes of acute chest pain
Cardiac troponin – needed to rule out a myocardial infarction
Echocardiogram – needed to visualise the heart function
Management
NSAID or colchicine with gastric protection and treatment of underlying cause
Constrictive pericarditis
This is a condition which occurs when the heart is encased in a rigid pericardium.
The rigid pericardium prevents the ventricles from filling leading to a reduced cardiac output, causing some symptoms of right sided heart failure.
It can occur secondary to any cause of pericarditis
Causes
Any cause of acute pericarditis
Symptoms
Signs of right heart failure – raised JVP, oedema, hepatomegaly, ascites
Shortness of breath
Positive Kussmaul sign – this is a paradoxical rise in the JVP on inspiration (usually JVP drops as intra-thoracic pressure decreases)
Key tests
CXR shows pericardial calcification
Echocardiogram may show reduced ejection fraction
Management
Pericardial stripping, a surgical procedure which peels away the pericardium from the heart
Cardiac Tamponade
This is a condition in which fluid collects within the pericardial sac, leading to compression of the ventricles impeding cardiac output.
If the fluid increases over time, the pericardial sac can hold up to 2 litres, whereas if the increase is rapid, as little as 300 ml can result in cardiac tamponade.
Causes
Pericarditis
Myocardial rupture
Aortic dissection
Malignancy
Symptoms
Beck’s triad – hypotension, quiet heart sounds, jugular venous distension
Cardiogenic shock – shortness of breath, weakness, light headedness, tachycardia
Pulsus paradox – an abnormally large drop in blood pressure during inspiration
Key tests
CXR shows an enlarged, globular heart
Echocardiogram shows an echo-free zone around the heart
ECG shows low voltage QRS complexes, which may alternate (electrical alternans)
Management
Pericardiocentesis to drain the fluid in the pericardial sac
