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66 Chapter 2: Cardiovascular system

friction rub is pathognomonic but may be transient, best Aetiology
heard at the left sternal edge accentuated by leaning for- Haemopericardium, tuberculous pericarditis and acute
ward and held expiration. pericarditis may result in constrictive pericarditis. In
many cases there is no identifiable cause.
Complications
Pericarditis is often complicated by pericardial effusion Pathophysiology
and occasionally tamponade. Where there is an associ- Chronicinflammation,orhealingafteracutepericarditis
atedmyocarditis,featuresofheartfailuremaybepresent. may cause the pericardium to become thick, fibrous and
calcified. This surrounds and constricts the ventricles
such that the heart cannot fill properly, hence causing a
Macroscopy/microscopy
reductionincardiac output.
An acute inflammatory reaction with both pericardial
surfaces coated in a fibrin-rich exudate.
Clinical features
Thepredominantfeaturesareofright-sidedheartfailure:
Investigations
Raised jugular venous pressure, ascites, hepatomegaly,
ECG usually shows widespread ST elevation, concave

ankle and sacral oedema.
upwards (as opposed to the convex upward configu-
The JVP has a steep y descent (Friedreich’s sign). Dur-
ration of a myocardial infarction).
ing inspiration there is an increase in pressure and
Other investigations are required to help identify an

hence neck vein distension (Kussmaul’s sign).
underlying cause, e.g. FBC (infection), U&Es (renal
Pulsus paradoxus may occur, this is a greater than nor-
failure), ESR and cardiac enzymes (to exclude my-
malfallinpulsevolumeduringinspiration.Thisisdue
ocardial infarction).
to the transient reduction in left ventricular filling,
Chest X-ray may suggest a pericaridal effusion (glob-

which occurs as a result of reduction in pulmonary
ular looking heart with increased size of the cardiac
venous return to the left atrium during inspiration.
shadow).
There is initially sinus tachycardia and atrial fibrilla-
Other investigations may be indicated, including

tion may develop. Auscultation reveals soft S1 and S2
echocardiogram, viral titres and blood cultures.
with a loud diastolic (early third) heart sound or peri-
Pericardial aspiration may be used to obtain fluid for

cardial knock due to rapid but abbreviated ventricular
diagnosis, but is only considered where there is either
filling.
a significant fluid collection or an undetermined aeti-
ology.
Investigations
Chest X-ray is frequently normal but may show a rel-

Management
atively small heart. There may be a shell of calcified
Analgesia and anti-inflammatory treatment with aspirin
pericardium particularly on the lateral film.
or NSAIDs is usually effective. A small percentage of ECG shows low QRS voltages with flat or inverted T
patients may have a later relapse when steroids may be
waves.
required. Drainage is necessary for cardiac tamponade. Echocardiogram can sometimes show thickening of
the pericardium and an abnormal ventricular filling
Prognosis pattern. However, it may be normal even in the pres-
Most cases of acute pericarditis, particularly of viral ori- ence of the disease.
gin, run a benign and self-limiting course. MRI is the investigation of choice to define the loca-
tion of pericardial thickening and also may evaluate
ventricular and valvular function.
Constrictive pericarditis
Definition Management
Acondition in which reduced elasticity of the peri- Medical intervention is of little value except for digoxin
cardium results in poor cardiac output. to control atrial fibrillation. The treatment of choice is