Transtelephonic monitoring (TTM) is a technology that allows patients to report symptoms and/or transmit data from a medical device (usually a pacemaker) over the phone for medical evaluation by their physician. TTM may be used to allow patients to have their pacemaker checks done over the phone, or to transmit data from an electrocardiograph (EKG) machine over the phone for evaluation. Signals from the devices are converted into sound waves, sent over the phone, received by the monitoring station at the other end of the phone, and reconverted back into the original signals. TTM may be significantly more convenient and less time-consuming than an office visit, but this technology is not a substitute for physician evaluation or the physician-patient relationship.

It is important to note that data cannot be transmitted to a monitoring station by cordless phone, including cell phones, because of electronic interference.