<prompt> A 52-year-old businessman with nephrotic syndrome after a non-stop flight from New York to New Delhi presents with sudden onset of breathlessness, haemoptysis, and chest pain. He is brought into Casualty in shock. His chest X-ray is normal. The ECG shows sinus tachycardia.PneumothoraxMyocardial infarctionPulmonary embolismAoic dissection  <response>: 1. In this patient no pulmonary edema, MI absent and aoic dissection also absent. 2. Nephrotic syndrome patient will be in hypercoagulable state, long flight- DVT- pulmonary embolism- acute Cor pulmonale 3. Most common causes of Cor pulmonale- pulmonary embolism 4. CXR is normal because it is only a small clot and clot usually not visible on X-ray 