A woman in her 70s with rheumatoid arthritis presented to the emergency department with progressive dysnoea and sharp chest pain radiating to her back over the preceding day. No recent thoracic trauma was recollected. Examination demonstrated frailty, hypotension with a mean arterial pressure of 50, normal heart sounds and reduced air entry at the right base on ausculation of lung fields. No radial asymetry or pulsus paradoxus was present. An ECG demonstrated left bundle-branch block. Twenty-four hour high sensitivity troponin was negative. Serial arterial gas haemoglobin within 30 min demonstrated haemoglobin drop from 10.8 g/dL to 8 g/dL. Chest X-ray demonstrated widened mediastinum, appearing wider than prior imaging a year previously. Emergency echocardiogram revealed a 1 cm pericardial effusion with fibrin deposition extending 1.8 cm anteriorly. No diastolic ventricular collapse or respiratory …