Author + information
- Ningchao Taoa,b,
- Haipeng Tanga,b,
- Yuanhao Qiua,b,
- Weihua Zhoua,b,
- Zhiyong Qiana,b,
- Yao Wanga,b,
- Xiaofeng Houa,b and
- Jiangang Zoua,b
Background: The U-shaped left-ventricular contraction pattern, identified by MRI and echocardiography, is associated with improved CRT response. Gated SPECT MPI can measure myocardial viability and mechanical dyssynchrony in a single scan. This study is aimed to applying gated MPI to identify contraction pattern and evaluate its influence to CRT response in patients with left bundle branch block (LBBB).
Methods: 58 patients with LBBB who met CRT guidelines, had pre-CRT MPI and received CRT were enrolled. MPI images were processed by Emory Cardiac Toolbox. The perfusion with <50% of maximum uptake was defined as scar. The regional contraction onsets (Figure 1) were used to identify contraction patterns. The U-shaped pattern was defined as presence of a significant delay in propagation direction (Figure 1A). The LVEF with ≥5% improvement after 6 months follow-up was defined as a responded CRT.
Results: 28 patients (48.3%) had a U-shaped pattern and 30 patients (51.7%) had a non-U-shaped pattern. The U-shaped group showed a significantly higher rate of response than the non-U-shaped group (89.3% vs. 56.7%; p=0.005). In addition, there were only 5 patients whose contraction block lines were inside scar and all of them were non-ischemic.
Conclusions: The U-shaped pattern identified by SPECT MPI is significantly associated with improved CRT response, which shows great promise to improve patient selection. Furthermore, the primary cause of U-shaped pattern is functional rather than scarring.
Poster Hall, Hall C
Saturday, March 18, 2017, 9:45 a.m.-10:30 a.m.
Session Title: Heart Failure and Cardiomyopathies: Heart Failure Gadgets Galore
Abstract Category: 14. Heart Failure and Cardiomyopathies: Therapy
Presentation Number: 1199-249
- 2017 American College of Cardiology Foundation