An inadvertent vent in the right ventricle (RV) resulted during dissection of a deep intramyocardial left anterior descending coronary artery (LAD), during off-pump coronary artery bypass grafting (OPCAB), led to pulmonary artery air embolism and hemodynamic instability, requiring conversion to cardiopulmonary bypass (CPB) prior to repair. This required a special maneuver in positioning the patient to identify the RV injury and prevent the pulmonary air embolism.