SWAN-GANZ CATHETER - A special hemodynamic monitoring device (long thin catheter) that is introduced into a large vein (in the neck, chest, or groin) and advanced through the right heart to the pulmonary artery. Measurements of cardiac function and blood pressure can be made with this device that can greatly increase the physician's diagnostic ability and provide a way to monitor the patient's response to different medications. May be used to diagnose pulmonary hypertension.