A 48-yr-old female with headache and dyspnoea

A 48-yr-old white female was referred for an abnormality on her plain chest radiograph in the setting of progressive exertional dyspnoea. She had initially sought a medical evaluation 2 months previously for worsening headaches and a magnetic resonance imaging (MRI) scan of her brain was ordered. This MRI revealed an old infarct in her right posterior-inferior cerebellar hemisphere. She underwent a transoesophageal echocardiogram that showed a structurally normal heart but a positive bubble contrast study suggesting a right to left shunt. The cardiologist interpreting the study noted that there was no evidence of intracardiac shunt, but the delay after venous injection of the contrast bubbles until their appearance in the left heart suggested an anomalous, perhaps congenital, systemic venous connection to the left atrium. Two days after the echocardiogram was completed, the patient presented to a local emergency department complaining of chest discomfort. She denied any cough, fevers, night sweats, or weight loss. Past history was significant for ∼20 pack-yrs of cigarette smoking, though she quit 15 yrs ago, and had 1–2 episodes of bronchitis per year. The patient's physical examination showed: temperature 37.8°C; pulse 72 beats·min−1; respirations 14 breaths·min−1; and blood pressure (BP) 135/75 mmHg. She was mildly obese and in no distress. Examination of skin, nose and mouth revealed no abnormalities. …