A system and method of treating a patient is described, where an implantable device is introduced into the patient and guided to an appropriate location using a 2-dimentsional X ray taken prior to the introduction of the device, and a fluoroscopic image taken from the same aspect during the procedure, and using the same portion of a physiological cycle. The implantable device may be a percutaneous aortic heart valve (PHV), and the location of the device may be determined with respect to specific bodily structures identified in the 2-dimensional X-ray, such as the aortic valve and the coronary ostia. The installation position of the device is selected so as to avoid obstruction of the coronary ostia.