The marker channel: a telemetric diagnostic aid.

Interpretation of ECG records from patients who have sophisticated pacemakers is often difficult. To address this problem, radiofrequency telemetry of diagnostic data is now being provided in varying forms from such pacemakers. A particularly useful aid to ECG analysis is offered by transmission of a Marker Channel which provides detailed information regarding occurrence and timing of pacing and sensing events. Use of the Marker Channel in combination with an appropriate programmer makes it possible to obtain ECGs with fully diagrammed pacemaker operation in minutes, with sufficient detail to free the user from the need to memorize unique pacemaker characteristics. This system is described and sample records are discussed.