Author + information
- Zhiyong Qian,
- Ningchao Tao,
- Yao Wang,
- Xiaofeng Hou and
- Jiangang Zou
Background: Few data for super-response to cardiac resynchronization therapy (CRT) were reported. Previous studies paid attention to left ventricular (LV) mechanical dyssynchrony in predicting response to CRT. However, a certain proportion of heart failure (HF) patients with left bundle branch block (LBBB) exhibited normal LV synchrony. We aimed to evaluate the echocardiographic response to CRT recipients with LBBB and homogeneous LV contraction pattern assessed by phase analysis of gated single-photon emission computed tomography.
Methods: Prospective, observational study of 58 HF patients with LBBB underwent LV synchrony evaluation and CRT implantation. Super-response is defined as a left ventricular ejection fraction (LVEF) over 45% or twice of baseline at 1-year follow-up. Homogeneous LV contraction pattern is characterized as LV activation spreading from septum to apex, anterior, and then inferior or lateral wall without acute change in propagation direction in the whole LV contraction process.
Results: Homogeneous contraction pattern was determined in 37.9% (22/58) of the patients at baseline evaluation. Compared with non-homogeneous group, patients in homogeneous group showed better LV synchrony (phase standard deviation: 26.9±14.2 vs. 60.9±16.2, p < 0.001; and phase histogram bandwidth: 81.4±43.9 vs. 211.5±67.6, p < 0.001). Super-response was more common in homogeneous group (16/22 vs. 15/36, p = 0.02) with LVEF improved from 34.0±2.0% to 53.7±6.0%. In multivariate analysis, only homogeneous pattern was associated with CRT super-response with an odds ratio of 3.66 (95% confidential interval = 1.09-11.64, p = 0.03). Intrinsic QRS measurement showed that QRS narrowing in homogeneous group was more notable than that in non-homogeneous group (-21.3 ms vs. -5.7 ms, p = 0.05). Three super-responders in homogeneous group and one in non-homogeneous group restored normal QRS duration.
Conclusions: Super-response in CRT recipients with LBBB and homogeneous LV contraction pattern were accompanied by reversal structural and electrical remodeling. The mechanism was supposed to be electrical disturbance-induced cardiomyopathy and needed further investigation.
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: 1199-246
- 2017 American College of Cardiology Foundation