The Influence of Test Window Width on Atrial Rhythm Classification in Dual Chamber Pacemakers

Abstract

IntroductionDual chamber pacing systems have been in use for more than ten years and have proven to provide superior hemodynamics compared to single chamber pacing systems. Since their introduction only minor modifications to tbe basic bebavior have been introduced. Tbe main principle of most dual cbamber pacemakers still consists of following all sensed atrial events, providing tbe ventricular rate does not exceed a certain, programmable upper rate limit. Pacemakers that control their upper rate by sensor information are becoming available, but so far only one pacemaker automatically reduces the upper rate limit when a pathological atrial rhythm is detected. A next step in dual cbamber pacing may consist of reliable beat-to-beat diagnosis of atrial sensed events. Tbis information in turn can influence the pacemaker response. Adaptive mode switching, whereby on a beat-to-beat basis tbe optimum pacemaker response is determined, is intended to provide maximum tracking of sensed atrial beats, with elimination of synchronization to pathological atrial rhythm.In tbis study beart rate variation is investigated and an atgoritbm that should reliably detect pathological rhythms based on tbe analysis of heart rhytbm alone is tested.

Automatic Mode Switching of Implantable Pacemakers: II. Clinical Performance of Current Algorithms and Their Programming

“…The Vitatron Diamond and Clarity DDDR (Vitatron Medical BV, Dieren, the Netherlands) pacemakers have a different AMS algorithm that use a physiological band to define normal versus pathological atrial rate. [20][21][22] A physiological atrial rate is calculated from the running average of the actual As or Ap atrial beats and the rate change in this moving average is limited to 2 beats/min (Fig. 7).…”

Different Automatic Mode Switching in DDDR Pacemakers

“…There are potential compromises between sensitivity and specificity with these algorithms, the balance of which may determine the frequency of arrhythmia-related symptoms. Atrial-based pacing is associated with a risk of developing atrial fibrillation lower than ventricular-based pacing for patients with sinus node dysfunction [22][23][24][25].…”