Under local anesthesia, a biopsy catheter is placed into a vein in the neck, or groin, and advanced to the heart. Small samples of tissue are "pinched" off and taken out to be examined in the Pathology Lab. Information is used to evaluate, diagnose, and monitor the heart muscle prior to, and after, heart transplantation. Procedure may be done in conjunction with a Right Heart Catheterization. Patient is restricted to bed rest for approximately 2-4 hours after the procedure. Usually the patient may eat and drink after the procedure, when awake.