How Do QRS Pattern and Duration Affect Response to CRT?

In a large cohort of Medicare patients receiving resynchronization, outcomes were best in those with left bundle-branch block and QRS durations ≥150 milliseconds.

In several clinical trials, cardiac resynchronization therapy (CRT) improved mortality and heart failure (HF) events (NEJM JW Cardiol Oct 29 2008, Sep 1 2009, and Nov 14 2010). Factors associated with super-responsiveness to CRT included female sex, left bundle-branch block (LBBB), QRS duration of ≥150 milliseconds, and nonischemic cardiomyopathy (NEJM JW Cardiol Aug 8 2012). Now, investigators have used the National Cardiovascular Data Registry's Implantable Cardioverter-Defibrillator Registry to assess outcomes in 24,169 Medicare-enrolled patients who received CRT defibrillators. Patients were divided into four groups based on QRS duration (120–149 ms vs. ≥150 ms) and morphology (LBBB vs. non-LBBB).

At 3-year follow-up, mortality was lowes…

Reviewing Author

Mark S. Link, MD

Disclosures

Editorial BoardsCirculation; UpToDate

Mark S. Link, MD

Disclosures

Editorial BoardsCirculation; UpToDate

How Do QRS Pattern and Duration Affect Response to CRT?

Topics

Reviewing Author