PROGRESS in immunosuppression following heart transplantation (HTX) can be achieved either by introducing more specific immunosuppressive drugs or by improving rejection diagnosis and therapy control. Endomyocardial biopsy (EMB), the current golden standard of rejection surveillance, is an invasive method and cannot be repeated daily. Information gained by new methods for rejection monitoring should at least be equivalent to the reference method. CHARM (Computerized Heart Acute Rejection Monitoring) is a new, noninvasive method for graft surveillance following HTX. Rejection grade 2 or higher, according to the guidelines of the International Society for Heart and Lung Transplantation ISHLT 1 can be detected safely. Quicker and more frequent data acquisition further improves graft surveillance. he major advantage of noninvasive cardiac rejection monitoring is unrestricted access to intramyocardial electrograms (IE) at any time of the day. CHARM is a tool for daily rejection diagnosis.