Author + information
- Received July 21, 2009
- Revision received September 3, 2009
- Accepted September 16, 2009
- Published online February 1, 2010.
- Olusegun Oyenuga, MD,
- Hideyuki Hara, MD,
- Hidekazu Tanaka, MD,
- Han-Na Kim, MD,
- Evan C. Adelstein, MD,
- Samir Saba, MD and
- John Gorcsan III, MD⁎ ()
- ↵⁎Reprint requests and correspondence:
Dr. John Gorcsan III, University of Pittsburgh, Scaife 564, 200 Lothrop Street, Pittsburgh, Pennsylvania 15213-2582
Objectives To test the hypothesis that echocardiographic dyssynchrony may assist in the selection of patients with borderline QRS duration for cardiac resynchronization therapy (CRT).
Background Although echocardiographic dyssynchrony is currently not recommended to select patients with QRS duration widening for CRT, its utility in patients with borderline QRS widening is unclear.
Methods Of 221 consecutive heart failure patients with an ejection fraction (EF) ≤35% referred for CRT, 86 had a borderline QRS duration of 100 to 130 ms (115 ± 8 ms) and 135 patients had wide QRS >130 ms (168 ± 26 ms). Dyssynchrony was assessed using interventricular mechanical delay, tissue Doppler imaging longitudinal velocity opposing wall delay, and speckle tracking radial strain for septal to posterior wall delay. Response to CRT was defined as ≥15% increase in EF, and reverse remodeling as ≥10% decrease in end-systolic volume.
Results There were 201 patients with baseline quantitative echocardiographic data available, and 187 with follow-up data available 8 ± 5 months after CRT. A smaller proportion of borderline QRS duration patients (53%) were EF responders compared with 75% with widened QRS (p < 0.05). Interventricular mechanical delay ≥40 ms and opposing wall delay ≥65 ms were predictive of EF response in the wide QRS duration group, but not the borderline QRS duration group. Speckle tracking radial dyssynchrony ≥130 ms, however, was predictive of EF response in both wide QRS interval patients (88% sensitivity, 74% specificity) and borderline QRS interval patients (79% sensitivity, 82% specificity) and associated reverse remodeling with reduction in end-systolic volume (p < 0.0005).
Conclusions Radial dyssynchrony by speckle tracking strain was associated with EF and reverse remodeling response to CRT in patients with borderline QRS duration and has the potential to assist with patient selection.
Dr. Gorcsan was supported in part by NIH award K24 HL04503-01 and receives research support in the form of donated equipment from the GE Corporation, and research grant support from Medtronic, St. Jude Medical, and Biotronik.
- Received July 21, 2009.
- Revision received September 3, 2009.
- Accepted September 16, 2009.
- American College of Cardiology Foundation