Malignant pericardial effusions are well recognised in malignancy [1, 2], and need to be diagnosed early in light of their life-threatening nature should tamponade occur. Various cases have been reported with many primary malignancies and the best course of oncological management is a source of some debate [3, 4]. It is however much more uncommon for the pericardial effusion to be the presenting feature of a hitherto undiagnosed malignancy with literature searches revealing very few reported such presentations .
Malignant pericardial effusion sufficient to require drainage is a poor prognostic factor, with reported median survival of 6.1 months .
Other common causes of pericardial effusions include acute myocardial infarction, PCI, uraemia, tuberculosis, infection, connective tissue disorders and trauma. The aetiology is unknown in 40 - 85% of cases .
Patient's presentation and development of symptoms depends on three principle factors - the volume of the pericardial effusion, the rate of accumulation and the elasticity of the pericardium. Larger volume effusions are better tolerated if the rate of accumulation is slow and the pericardial elasticity is high.
Patients do infrequently present in a state of haemodynamic embarrassment secondary to pericardial tamponade from their effusion. Clinical parameters suggesting this include hypotension, tachycardia, elevated JVP, quiet heart sounds, oliguria, and pulsus paradoxus. A friction rub is pathognomonic but frequently absent. ECG changes include low voltage complexes and ST segment changes that can mimic those seen in pericarditis. The diagnosis is confirmed with echocardiography, and findings indicating tamponade include diastolic collapse of the right atrium or ventricle with respiratory Doppler variation in transvalvar flows .
The treatment of cardiac tamponade is drainage of the effusion. Medical measures should only be utilised whilst arrangements for this are made and should not be viewed as alternatives. Intravenous resuscitation in the volume deplete patient may boost right heart filling pressures, whilst mechanical ventilation increases intrathoracic pressure thus impeding right sided filling pressures and can therefore be counter-productive. As adrenergic activation is already high in tamponade inotropic agents are not regarded as beneficial but are frequently trialled [8, 9].
Pericardiocentesis should be carried out in a cardiac catheter laboratory by experienced staff with appropriate nursing and technical support. Rarely clinical urgency will necessitate "blind" intervention in less than ideal facilities. This should be regarded as only being indicated in an absolute emergency. A 15 cm 18 gauge pericardiocentesis needle should be inserted just left of the xiphoid process until just behind the bony ribcage. It should then be angled at about 20o to the abdominal wall, aiming for the left shoulder tip. Lignocaine should be infiltrated as the needle is advanced, and repeated aspirations should be rewarded with a feeling of "give" once access to the pericardial sac is achieved. Complications include pneumothorax, arrythmias, ventricular laceration, and pyopericardium .
Pericardial window formation prevents pericardial fluid from reaccumulating following the removal of a pericardiocentesis drain. This can be done by thoracoscopy or by a subxiphoid approach. Where thoracoscopy would be preferred but is unavailable as minithoracotomy may be used instead. The thoracoscopic technique permits visualisation of the pericardium and pleura to allow adequate tissue to be sampled for histology when the underlying cause of the effusion is uncertain, and is generally preferred for when pleural drainage is needed as well. However, in malignant pericardial effusions it risks contamination of the pleural space with cancerous cells and a subxiphoid approach is utilised. A retrospective analysis comparing subxiphoid and thoracoscopic techniques found they had similar recurrence rates, postoperative complications, lengths of stay and need of intensive care unit admission .
Teaching Points: Pericardial effusions are recognised complications of malignancy;
Initial presentation of a malignancy with a pericardial effusion is unusual;
Presentation with cardiac tamponade is a medical emergency requiring prompt and expert treatment;
Pericardiocentesis is a safe procedure in expert hands with echocardiographic or fluoroscopic monitoring;
Blind Pericardiocentesis should only ever be attempted in an absolute emergency.