Reduction of RV pacing by continuous optimization of the AV interval

Goran Milasinovic, Johannes Sperzel, Timothy W. Smith, Hardwin Mead, Johan Brandt, Wesley K. Haisty, J. Russell Bailey, Marc Roelke, Jay Simonson, Bart Gerritse, Jennifer Englund, Steven J. Compton

Research output: Contribution to journalArticlepeer-review

28 Scopus citations


Background: In patients requiring permanent pacing, preservation of intrinsic ventricular activation is preferred whenever possible. The Search AV+ (SAV+) algorithm in Medtronic EnPulse™ dual-chamber pacemakers can increase atrioventricular (AV) intervals to 320 ms in patients with intact or intermittent AV conduction. This prospective, multicenter study compared the percentage of ventricular pacing with and without AV interval extension. Methods: Among 197 patients enrolled in the study, the percentage of ventricular-paced beats was evaluated via device diagnostics at the 1-month follow-up. Patient cohorts were defined by clinician assessment of conduction via a 1:1 AV conduction test at the 2-week follow-up. The observed percentage of ventricular pacing with SAV + ON and the predicted percentage of ventricular pacing with SAV + OFF were determined from the SAV + histogram data for the period between the 2-week and 1-month follow-up visits. Results: Of 197 patients, 110 (55.8%) had intact 1:1 AV conduction, of which 109 had 1-month data. SAV + remained ON in 99/109 patients; 10 patients had intrinsic A-V conduction intervals beyond SAV + nominal and therefore SAV + disabled. The mean percentage of ventricular pacing in the 109 patients was SAV+ ON = 23.1% (median 3.7%) versus SAV + OFF = 97.2% (median 99.7%). In 87 patients without 1:1 AV conduction, SAV + was programmed OFF in 6, automatically disabled in 52, and remained ON in 29. In 8 of these patients, 80-100% reduction in ventricular pacing was observed with SAV + ON. Conclusion: The Search AV+ algorithm in the EnPulse pacemaker effectively promotes intrinsic ventricular activation and substantially reduces unnecessary ventricular pacing.

Original languageEnglish
Pages (from-to)406-412
Number of pages7
JournalPACE - Pacing and Clinical Electrophysiology
Issue number4
StatePublished - Apr 2006


  • Dual-chamber pacing
  • Intrinsic ventricular activation
  • Search AV+
  • Unnecessary ventricular pacing


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