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Clinical applications of the threshold tracking pacemaker

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      Abstract

      The concept of automatic threshold tracking is the most recent adaptation of artificial cardiac pacemakers to physiologic needs. Earlier pacemaker innovations were primarily in the area of timing of impulse delivery, whereas more recent changes have focused on alteration of the amplitude and duration of the pacemaker stimulus. Matching of this stimulus to the cardiac excitation threshold is important because a stimulus greater than necessary is wasteful of battery energy and may produce arrhythmias, whereas a stimulus of less than threshold intensity fails to pace the heart. Because of the wide range of clinically encountered threshold levels it is impossible to design a fixed output pacer that is efficient and safe for all patients at all times.
      The threshold tracking pacemaker searches for and finds the threshold level, and adjusts its stimulus to just above this level. The device ensures an adequate safety margin of stimulation, but reduces the stimulus level to the lowest safe level possible. It is fully automatic, adjusts immediately to any threshold changes and is not dependent on manual alteration.
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      References

        • Preston TA
        • Bowers DL
        The automatic threshold tracking pacemaker.
        Med Inst. 1974; 8: 322-355
        • Preston TA
        A new temporary pacing catheter with improved sensing and safety characteristics.
        Am Heart J. 1974; 88: 289-293
      1. Thalen HJ Cardiac Pacing, Proceedings of the 4th International Symposium. Assen, The Netherlands, Van Gorcum1973
        • Mugica J
        • Lazarus B
        • Buffet J
        • et al.
        Pacemaker with automatic adaptation to the pacing threshold.
        in: Thalen HJ Cardiac Pacing, Proceedings of the 4th International Symposium. Assen, The Netherlands, Van Gorcum1973: 150-155
        • Preston TA
        • Bowers DL
        Pacing, Proceedings of the 4th International Symposium. Assen. third edition. Report of a continuous threshold tracking system. Assen, The Netherlands, Van Gorcum1973: 295-299
        • Funke HD
        Ein Quarzgesteuerter Schwellwert-Schrittmacher in Weitgehend Integrierter Schaltungstechnik.
        Biomed Tech. 1973; 18: 87-91
        • Jlrak TL
        • Helland JR
        • Larson K
        Monitoring canine cardiac Stimulation threshold with an implanted automatic threshold-following pacemaker (abstr).
        Med Inst. 1974; 8: 41
        • Thalen HJ
        • van den Berg J
        • van der Helde JN
        • et al.
        The Artificial Cardiac Pacemaker.
        in: Charles C Thomas and Van Gorcum, Assen, The Netherlands1969: 177
      2. Furman S: Personal communication, November 21, 1973

        • Preston TA
        Anodal stimulation as a cause of pacemaker-induced ventricular fibrillation.
        Am Heart J. 1973; 86: 366-372
        • Spear JF
        • Moore EN
        • Horowitz LN
        Effect of current pulses delivered during the ventricular vulnerable period upon the ventricular fibrillation threshold.
        Am J Cardiol. 1973; 32: 814-822