The purpose of this study is to 1) identify individuals scheduled to undergo elective ERCP as part of their plan-of-care and perform transthoracic echocardiography for surveillance of intracardiac air embolus 2) record aspects of their past medical history that may potentially contribute to increased risk of systemic venous air embolus. This evaluation has not been presented in the literature and the primary end-point of this study would be to determine the frequency at which venous air embolus associated with ERCP occurs.