A 21-year-old college student with a history of mitral valve prolapse had sudden left back pain followed by dull persistent chest pain and breathlessness at rest. The initial examination did not show any specific finding. The chest distress lasted for approximately 2 hours. She returned for help and underwent an ECG, which revealed normal sinus rhythm, vertical frontal axis, and loss of r-wave progression in precordial leads (Figure 1). Chest radiography revealed a pleural line over the left lung (Figure 2, arrow) and a bulla over the left lower lung (Figure 2, arrowhead). Contrast-enhanced computed tomography before drainage of the lung identified a large bulla around the border of the left ventricle (Figure 3, asterisk), extending anteriorly. After drainage with a chest tube, repeated ECG revealed normal progression of the r wave in precordial leads (Figure 4). The patient was discharged from the hospital in good condition.
