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Part 1: SyncAV CRT Technology - Options to Achieve the Narrowest QRS for Improved Response1

Abbott Cardiac Rhythm Management | March 13, 2023
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Every patient deserves the life-changing therapy that SyncAV™ CRT technology delivers. This 4-part series examines the different facets – and positive clinical outcomes – that this Abbott-exclusive technology provides. Part 1 defines what SyncAV CRT technology is, and starts exploring how the technology achieves QRS narrowing and its associated benefits to patients.

SyncAV CRT technology dynamically adjusts the timing of AV delays based on the intrinsic AV interval to deliver triple fusion pacing. Triple fusion pacing is the combination of intrinsic activation wavefronts with both the LV and RV pacing wavefronts. This patient-tailored algorithm shortens the QRS duration (QRSd) beyond what conventional biventricular (BiV) pacing can.2 SyncAV pacing provides the most QRS narrowing options at implant for patients, which allows higher patient survival rate, and has demonstrated a 30% cumulative reduction of heart failure hospitalizations at 2 years.3

100% of patients had a narrower QRS when SyncAV CRT technology was turned on1 and CRT-induced QRS narrowing has been shown to improve clinical outcomes for heart failure patients.4,5

Going a step further, in patients with left bundle-branch block (LBBB), QRS narrowing after CRT implant is associated with 2X lower mortality.6

Stay tuned for Part 2 of this series, which will further examine QRS narrowing benefits with SyncAV pacing, and click here to view Abbott’s full suite of CRT products.


  1. Varma N, O’Donnell D, Bassiouny M, et al. Programming cardiac resynchronization therapy for electrical synchrony: reaching beyond left bundle branch block and left ventricular activation delay. J Am Heart Assoc. Accessed 1/9/2023. https://www.ahajournals.org/doi/full/10.1161/JAHA.117.007489.
  2. Wang Z, Pan L, Zhang B, et al. Improvement of LV Reverse Remodeling Using Dynamic Programming of Fusion-Optimized Atrioventricular Intervals in Cardia Resynchronization. Therapy. Frontiers in Cardiovascular Medicine. August 2021. 
  3. Varma, N., Gain in CRT Efficacy with Dynamic Electrical Optimization: Real World Effect of SyncAV™ CRT on Heart Failure Hospitalizations. Poster presented at EHRA. May 2020. Accessed February 1, 2023. https://pubmed.ncbi.nlm.nih.gov/33965608/.
  4. Appert, L, Menet, A, Altes, A, et al. Clinical significance of electromechanical dyssynchrony and QRS narrowing in patients with heart failure receiving cardiac resynchronization therapy. Canadian Journal of Cardiology. January 1, 2019. Accessed January 8, 2023. http://doi.org/10.1016/j.cjca.2018.10.019.
  5. Okafor O, Zegard A, van Dam P, et al. Changes in QRS area and QRS duration after cardiac resynchronization therapy predict cardiac mortality, heart failure hospitalizations, and ventricular arrhythmias. J Am Heart Assoc. October 28, 2019. Accessed January 8, 2023. https://www.ahajournals.org/doi/10.1161/JAHA.119.013539.
  6. Jastrzębski M, Baranchuk A, Fijorek K, et al. Cardiac resynchronization therapy-induced acute shortening of QRS duration predicts long-term mortality only in patients with left bundle branch block. Europace. February 2019. Accessed February 1, 2023. https://doi.org/10.1093/europace/euy254.

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