Chapter 9
Pericardial diseases
Aetiology
The pericardium may be involved in the large number of disease processes listed in the box below. In some patients, pericardial disease is the primary disease process dominating the clinical picture, whereas in others it is a manifestation of a systemic disease. The most common causes are idiopathic, viral, uraemic, neoplastic, tuberculous pericarditis, and acute myocardial infarction (MI). The spectrum of pericardial disease is determined by the age and social circumstances of the patient. In an elderly North American and Western European population, the commonest causes are malignancy, followed by uraemia and MI. In less privileged communities and in developing countries, tuberculosis (TB) is still the predominant cause of pericardial disease.
Causes of pericardial disease
Syndromes of pericardial disease
Pericardial reaction to the various disease processes is limited, and we are thus able to distinguish five clinical and pathological forms of pericarditis:
Acute pericarditis without effusion
(‘Dry’ pericarditis)
Aetiology: Any of the causes listed in the box on Aetiology, p. 460 may cause dry pericarditis. The clinical syndrome is commonly seen in acute viral pericarditis or after MI.
Pathology: There is a fibrinous exudate with an inflammatory reaction involving the visceral and parietal pericardium. The epicardium is also involved and this accounts for the electrocardiography (ECG) changes that are seen, and the rise in cardiac enzymes (e.g. troponin I).
Symptoms: Sharp, stabbing, central chest pain is common, with radiation to the shoulders and upper arm. It is relieved by sitting up and leaning forward, and aggravated by lying down, and may be accentuated by inspiration, cough, swallowing, or movement of the trunk. Fever, night sweats, and other constitutional symptoms may be present, depending on the underlying cause.
Signs: A pericardial friction rub is frequently heard. This is a superficial, scratchy, grating sound that is best heard in the second to fourth intercostal spaces when pressure is exerted on the diaphragm of the stethoscope. Positioning the patient leaning forward and listening in held inspiration may bring it out. The rub is classically described as being triphasic. Usually you hear at least two components due to atrial systole and ventricular systole. Occasionally, a third component attributed to rapid ventricular filling is heard.
ECG: The patient is usually in sinus rhythm but atrial fibrillation (AF) may occur. In the early stages there is widespread ST segment elevation with concavity directed upwards, and PR segment deviation opposite to the polarity of the P wave. After a few days the ST segments, followed by PR segments, return to normal, and T waves become inverted.
Chest X-ray (CXR): The cardiac shadow is not enlarged in dry pericarditis.
Differential diagnosis: Acute pericarditis must be differentiated from MI, spontaneous pneumothorax, and pleurisy.
Diagnosis of acute pericarditis is based on typical symptoms of chest pain, pericardial rub, and/or characteristic ECG changes.
Management: Treat the underlying cause. Good pain relief can be achieved by the use of non-steroidal anti-inflammatory agents (NSAIDs).
Pericardial effusion with or without tamponade
Aetiology: Any of the causes listed in the box on Aetiology, p. 460 may cause pericardial effusion. Large effusions are common with neoplasia, TB, uraemic pericarditis, and myxoedema.
Pathology: In addition to fibrinous inflammation, there is significant fluid exudation. The pericardial fluid may be serous, sero-sanguineous, haemorrhagic, or purulent, depending on the underlying cause. Haemorrhagic effusion is common in TB or neoplasia. Brownish fluid with an anchovy-sauce appearance is highly suggestive of amoebic pericarditis.
Clinical features: The clinical presentation varies, depending on the rate of accummulation of the fluid, the amount of fluid that accumulates, and the stage at which the patient is first seen.
Symptoms: Chest pain may be typically pericardial (as described under dry pericarditis), or it may be dull and heavy due to distension of the pericardium. Dyspnoea is common, and orthopnoea may occur later in the course of the disease. Cough may be present due to compression of surrounding structures. Constitutional symptoms may be present, depending on the cause of the disease.
Signs: Typically, praecordial dullness extends beyond the apex beat (which may be impalpable), and dullness is present to the right of the sternum. Dullness and bronchial breathing at the left base posteriorly may be found, due to compression of the left lower lobe bronchus (Ewart’s sign). Cardiac tamponade should be considered in a patient with hypotension, raised jugular venous pressure (JVP), and quiet heart sounds (Beck’s triad). The primary defect in cardiac tamponade is interference with diastolic filling of the heart. The other clinical features of cardiac tamponade are the presence of tachycardia, pulsus paradoxus (fall in systolic blood pressure on inspiration of >10 mmHg or inspiratory fall in systolic blood pressure that exceeds half the pulse pressure), elevated JVP with brisk ‘x’ descents and absent ‘y’ descents, rise in JVP on inspiration (Kussmaul’s sign), dyspnoea or tachypnoea with clear lungs, and hepatomegaly.
ECG: Sinus tachycardia, generalized low-voltage QRS complexes with non-specific ST segment and T-wave changes. Electrical alternans, involving the QRS complex, suggests the presence of a massive pericardial effusion. Total electrical alternans (P-QRS-T), which is uncommon, is pathognomonic of cardiac tamponade.
Echocardiography: Is diagnostic, showing an ECHO-free zone surrounding the heart. The fluid may not be evenly distributed. Diastolic collapse of the right ventricle and right atrium indicate cardiac tamponade. The following features are more common in patients with tuberculous or malignant causes of pericardial effusion: soft tissue density masses, thickening of the visceral pericardium, and presence of fibrinous strands. The hallmark of benign, idiopathic effusion is a clear ECHO-free space, whereas malignancy, bacterial infection, and haemorrhagic effusions are more likely to have solid components or stranding.
CXR: Shows a large globular heart, usually with clear lung fields.
Cardiac catheterization: Establishes the diagnosis and severity of tamponade. The important findings are:
Differential diagnosis: Myocardial infarction and pulmonary embolism.
Management
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