A 22-year-old woman presented with a 3-day history of fever, retrosternal chest pain and exertional dyspnoea. Her heart rate was 130 bpm with a blood pressure level of 109/68 mmHg. Physical examination suggested tamponade: distended jugular veins, pulsus paradoxus and muffled heart tones. The chest radiography was notable for the characteristic water-bottle sign (Figure, A).1 Contrast-enhanced chest computed tomography demonstrated a massive pericardial effusion (Figure, B) associated with venous engorgement of the superior and inferior vena cava (SVC, IVC), prevascular space (arrows), and bilateral axillary veins (arrowheads). An emergency thoracoscopic pericardial window was performed and 620 mL of bloody fluid was drained.