Atrioventricular delay programming in cardiac resynchronization therapy devices: fixed or adaptive? A randomized monocenter trial

J Electrocardiol. 2012 Nov-Dec;45(6):783-6. doi: 10.1016/j.jelectrocard.2012.05.005. Epub 2012 Jun 20.


Introduction: Cardiac resynchronization therapy devices are routinely programmed on fixed atrioventricular delays (AVD) under resting conditions based on echocardiographic techniques. Whether this AVD also ensures optimal exercise hemodynamics, is unclear.

Methods: In order to compare fixed-AVD with rate-adaptive AVD, 100 patients with cardiac resynchronization therapy systems and sinus rhythm were randomized to fixed-AVD or adaptive-AVD. The patients then underwent bicycle ergometry with noninvasive hemodynamic monitoring. At rest and at peak exercise, stroke volume, cardiac output, and cardiac index were determined using "electrical velocimetry."

Results: There were no significant differences in clinical characteristics and baseline hemodynamic parameters between fixed or adaptive AVD. In patients randomized to adaptive AVD, a trend towards higher stroke volume, cardiac output, and cardiac index at peak exercise was encountered.

Conclusions: Based on the trend towards better exercise hemodynamics demonstrated by this pilot study, a randomized follow-up study with clinical end points appears to be justified to clarify this issue.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Algorithms*
  • Cardiac Resynchronization Therapy / methods*
  • Cardiac Resynchronization Therapy Devices
  • Diagnosis, Computer-Assisted / instrumentation
  • Diagnosis, Computer-Assisted / methods*
  • Electrocardiography / instrumentation
  • Electrocardiography / methods*
  • Female
  • Heart Failure / diagnosis*
  • Heart Failure / prevention & control*
  • Humans
  • Male
  • Middle Aged
  • Therapy, Computer-Assisted / instrumentation
  • Therapy, Computer-Assisted / methods*
  • Treatment Outcome