Solution: Pertinent finding in this case is air that appears within the left ventricle during the procedure. Air embolism is a rare, but dire complication of cardiothoracic interventions. It is more frequently seen in the setting of cardiac and pulmonary surgery, but can be seen in the setting of percutaneous interventions, including lung biopsy. The exact mechanism is not known, but likely is related to one of two occurences. If the needle is positioned within a pulmonary vein and the stylet is not in place when the patient inspires, then air will be pulled into the needle and thus the pulmonary vein, creating an air embolism. Alternatively, if the needle traverses both a pulmonary vein and an airway, a temporary fistulous connection may be created, with subsequent air embolism. Systemic air emboli are generally not life threatening or dangerous since they ultimately end up in the lungs are are resorbed. However, pulmonary venous sir emboli are dangerous because they can go to the brain or the coronary arteries resulting in stroke and myocardial infarction. Treatment is trendelenberg positioning to try to prevent further embolism to the head and 100% oxygen, possibly in a hyperbaric chamber. Outcome can be fatal, but if treated appropriately and quickly patient\'s often return to baseline function. A somewhat delayed sequelae can be platelet aggregation in the vasculature affected by the embolism, so some would recommend aspirin or other anti-platelet medication as part of the treatment.