All individuals that meet inclusion criteria will be approached and consented in the pre-operative area prior to the planned procedure (ERCP). Their past medical history will be reviewed with the patient and special attention placed on particular co-morbid conditions that might be related to this phenomenon including but not limited to: portal hypertension, cirrhosis, portal vein thrombosis, and recent liver biopsy. The patient will then proceed to the procedure room as planned and while the patient is placed in the left lateral decubitus position and induced under anesthesia. An echocardiography-trained anesthesiologist will perform a transthoracic echocardiogram (TTE) concurrently while the gastroenterologist is performing the ERCP. We plan on conducting serial images at least every ten to fifteen minutes throughout the ERCP and more often as needed. At the conclusion of the procedure (ERCP) if there are no significant findings on TTE the patient will be returned to the supine position and taken to the recovery room. The written record of the TTE will then be entered into the study database within a separate research chart. In the event that the TTE shows the presence of intracardiac air embolus during the procedure the member of the study group performing the TTE will notify the endoscopist and anesthesia provider of the findings if the findings are significant enough to require a change in the patient's medical care. Reference to the algorithm will be made in each case and be available online if needed. Unless a moderate to severe embolic event occurs, the findings will not be communicated to the gastroenterologist so that he is blinded to the result maintained in the research chart. The purpose of this is to keep clinically insignificant emboli from being reported in the patient's medical record.