Transmyocardial laser revascularization: A procedure by which a physician uses a laser to make holes in the heart to relieve the pain of severe angina. Transmyocardial laser revascularization has been done from both the outside and inside of the heart. When done from the outside, a laser (carbon dioxide or holmium laser) is placed in proximity to the left ventricle of the heart and sufficient energy is applied to create small channels from the outside (epicardial) surface to the inside (endocardial) surface of the heart. Thus, a number (10-50) of tiny holes are created right through the heart muscle (the myocardium). More recently, this procedure has moved into the cardiac catheterization lab and the laser works from the inside outward.