Strain-time curve analysis by speckle tracking echocardiography in cardiac resynchronization therapy: Insight into the pathophysiology of responders vs. non-responders

Cardiovascular Ultrasound

Research

Rodolfo D. Benatti¹  James D. Thomas¹  Zoran B. Popović¹  Richard A. Grimm¹  Kimi Sato¹  Deborah Agler¹  Andrew C. Y. To²  Bruce L. Wilkoff³ 

[1]Section of Cardiovascular Imaging, Department of Cardiovascular Medicine, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, USA

[2]Section of Cardiovascular Imaging, Department of Cardiovascular Medicine, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, USA

[3]Department of Cardiology, North Shore Hospital, 124 Shakespeare Rd, Takapuna, Auckland, New Zealand

[4]Section of Electrophysiology, Department of Cardiovascular Medicine, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, USA

关键词: Cardiac resynchronization therapy;    Left bundle branch block;    Dyssynchrony;   

DOI  :  10.1186/s12947-016-0057-4

 received in 2016-03-09, accepted in 2016-04-08,  发布年份 2016

来源: Springer

【 摘 要 】

BackgroundPatients with non-ischemic heart failure etiology and left bundle branch block (LBBB) show better response to cardiac resynchronization therapy (CRT). While these patients have the most pronounced left ventricular (LV) dyssynchrony, LV dyssynchrony assessment often fails to predict outcome. We hypothesized that patients with favorable outcome from CRT can be identified by a characteristic strain distribution pattern.MethodsFrom 313 patients who underwent CRT between 2003 and 2006, we identified 10 patients who were CRT non-responders (no LV end-systolic volume [LVESV] reduction) with non-ischemic cardiomyopathy and LBBB and compared with randomly selected CRT responders (n = 10; LVESV reduction ≥15 %). Longitudinal strain (εlong) data were obtained by speckle tracking echocardiography before and after (9 ± 5 months) CRT implantation and standardized segmental εlong-time curves were obtained by averaging individual patients.ResultsIn responders, ejection fraction (EF) increased from 25 ± 9 to 40 ± 11 % (p = 0.002), while in non-responders, EF was unchanged (20 ± 8 to 21 ± 5 %, p = 0.57). Global εlong was significantly lower in non-responders at pre CRT (p = 0.02) and only improved in responders (p = 0.04) after CRT. Pre CRT septal εlong -time curves in both groups showed early septal contraction with mid-systolic decrease, while lateral εlong showed early stretch followed by vigorous mid to late contraction. Restoration of contraction synchrony was observed in both groups, though non-responder remained low amplitude of εlong.ConclusionsCRT non-responders with LBBB and non-ischemic etiology showed a similar improvement of εlong pattern with responders after CRT implantation, while amplitude of εlong remained unchanged. Lower εlong in the non-responders may account for their poor response to CRT.

【 授权许可】

CC BY   
© To et al. 2016