Therapeutic system with implantable therapeutic unit (ITU) comprising control unit (CU), memory, telemetry unit connected (in)directly to CU for wireless bidirectional transmission of data to/from external device (ED) and detection unit for detecting physiological patient data or operational data. CU triggers outgoing data transmission (DT) from ITU to ED based on preselected internal events and establishes standby mode for reception on part of telemetry unit for receiving beginning (header) of incoming DT from ED to therapeutic unit exclusively within preselected response time window after DT from ITU to ED. System designed to add to incoming DT follow-up signaling data which signals an imminent follow-up examination, whereby CU also prompts sensor unit at preselected time point in response to receipt of follow-up signaling data to detect preselected physiological data required for follow-up examination or to detect operational data of therapeutic and store in memory and transmit with subsequent outgoing DT to ED.