Research Activities, October 2013
QRS duration good indicator of who will benefit from a pacemaker
Comparative Effectiveness Research
Research from AHRQ's Effective Health Care Program suggests that QRS duration (measurement of electrical conducting time measured with electrocardiogram) is a good indicator of which patients with heart failure will benefit from a pacemaker.
The research found that, among fee-for-service Medicare beneficiaries undergoing cardiac resynchronization therapy defibrillator (CRT-D) implantation in routine clinical practice, patients with left bundle-branch block (LBBB, a condition that causes disorganized electrical activity in the heart) and a QRS duration of 150 millisecond (ms) or greater, compared with LBBB and QRS duration less than 150 ms or no LBBB regardless of QRS duration, had lower risks of mortality and heart failure readmission.
These findings support the use of QRS morphology and duration to help identify patients who will have the greatest benefit from CRT-D implantation. The findings on patients receiving CRT-D in clinical practice are consistent with the recently updated American College of Cardiology/American Heart Association/Heart Rhythm Society Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities, which emphasize the importance of QRS duration and morphology on patient selection for CRT therapy. The guidelines provide stronger recommendations for patients with LBBB compared to those without, and for patients with more prolonged QRS duration.
See "QRS Duration, Bundle-Branch Block Morphology, and Outcomes Among Older Patients With Heart Failure Receiving Cardiac Resynchronization Therapy," by Pamela N. Peterson, M.D. M.S.P.H., Melissa A. Greiner, M.S., Laura G. Qualls, M.S., and others in JAMA Internal Medicine 310 (6), 2013.