HOLTER RECORDINGS WITH CONTINUOUS MARKER ANNOTATIONS - A NEW TOOL IN PACEMAKER DIAGNOSTICS

Pacemakers provide marker annotations to facilitate the interpretation of pacemaker electrocardiograms (ECGs) and can be used in cases of su spected pacemaker malfunction or to understand pacemaker behavior. Due to the need for a programmer, only short-term evaluations are possibl e. We evaluated a prototype Telemetry Data Logger (TDL) designed to co ntinuously transfer markers from the pacemaker to a conventional Holte r recorder. A miniaturized telemetry receiving coil was attached to pa tient's skin above the pacemaker, which was programmed to transmit mar kers continuously. The TDL, which receives and converts markers into e ight positive and eight negative deflections, ranging from -2.5 to +2. 5 mV in amplitude, was connected to one channel of a conventional Holt er recorder (Tracker 2). We performed 20 Holters in 13 patients who ha d implanted VDDR or DDDR devices from the same manufacturer and evalua ted three versions of software. Marker transmission was possible in al l patients, producing Holter ECGs with complete marker annotations. Ar tifacts occurred < 4 % of the time. A 50-ms rectangular pulse was opti mal for marker interpretation. The device, which was easy to use and w ell accepted by the patients, assisted in the diagnosis of inappropria te pacemaker programming, even when the such ce ECG seemed to show reg ular pacemaker function. In the presence of low quality surface ECGs, marker annotations allowed the assessment of pacemaker function. The c apability to annotate the onset of special algorithms, like tachycardi a termination algorithms or mode switching, facilitates interpretation of pacemaker behavior, enabling a reliable assessment of the appropri ateness of such algorithms. Conclusion: The TDL effectively enables pa cemaker markers to be inscribed onto a conventional Holter recording, facilitating the interpretation of pacemaker ECGs and the diagnosis of inappropriate pacemaker programming even when not discernible from th e surface ECG alone.