Quiz

SafeR 1: switch for first degree atrioventricular block

Patient

  • 65-year-old man
  • Reply DR pacemaker (Sorin) for sinus dysfunction
  • SafeR algorithm
  • programmed value for long PR 350 ms (AR 450 ms)
  • episodes of switch to DDD for first degree AV block (AVB1)  recorded in AIDA (memory of the device)

Tracing 

  • atrial pacing with ventricular sensing (AR)
  • AR intervals between 367 and 406 ms (less than the programmed value)
  • prolongation of the AR intervals (> 450 ms)
  • after 6 consecutive cycles with AR interval > 450 ms, switch to DDD (vertical line)
  • atrial and ventricular pacing

 

Comments

  • the device switches to DDD when PR or AR intervals are longer than the programmed maximum programmable value during 6 consecutive cycles
  • only the long PR (sensed atrial activity) interval is programmable
  • the long AR value (paced atrial activity) = long PR + 100 ms
  • The AVB I (first degree AV block) criterion can be programmed to: rest + exercise (the device may switch to DDD during rest and exercise phases) or to exercise only (the device may switch to DDD during exercise phase only)

 

SafeR 1: switch for first degree atrioventricular block