Mode switching in dual chamber pacemakers: Effect of onset criteria on arrhythmia-related symptoms

Academic Article


  • Aims Various mode-switching algorithms are available with different tachyarrhythmia detection criteria to be satisfied to initiate mode-switching. This study evaluated three different mode-switching algorithms in patients with paroxysmal atrial fibrillation. Methods and Results Seventeen patients completed the study. Three mode-switching algorithms were downloaded as software into the pacemaker, each for 1 month in a single-blind, randomized sequence. The criteria to initiate mode-switching were: mean atrial rate ('standard'), '4-of-7' or '1-of-1' atrial intervals to exceed the atrial detection rate. Symptoms for each were measured using the Symptom Checklist-Frequency and Severity index. The median number of mode-switch episodes increased from 20 for 'standard' to 39 for '4-of-7' (P=0·029 vs 'standard') and 103 for '1-of-1' (P=0·0012 vs 'standard') onset criteria. Median duration of episodes decreased from 2-5 min with 'standard' to 1·4 min with '4-of-7' and 0·4 min with '1-of-1' onset criteria. Frequency of symptoms was lower using '4-of-7' (18·2 ± 12·0 vs 23 ± 12·0, P=0·08) or '1-of-1' (20·4 ± 12·4 vs 23 ± 12·0, P=0·07) than 'standard' onset criteria. Severity of arrhythmia tended to be less with either '4-of-7' (16 ± 10·4 vs 19·1 ± 19·4, P=0·12) or '1-of-1' (17·5 ± 10·3 vs 19·1 ± 9·4, P=0·18) than with 'standard' onset criteria. Conclusions The more sensitive onset criteria for detection of atrial tachyarrhythmias were associated with lower frequency and severity of symptoms.
  • Authors

    Published In

  • Europace  Journal
  • Digital Object Identifier (doi)

    Author List

  • Marshall HJ; Kay GN; Hess M; Plumb VJ; Bubien RS; Hummel J; Dawson D; Markewitz T; Gammage MD
  • Start Page

  • 49
  • End Page

  • 54
  • Volume

  • 1
  • Issue

  • 1