左心房收缩期应变和应变率对心脏再同步治疗疗效的影响

背景　左心房功能是心脏整体功能的重要组成部分，左心房容积能够独立影响心脏再同步治疗（CRT）疗效。目的　本研究试图通过二维斑点追踪技术量化评价左心房功能，评价左心房收缩期应变（Sa）和应变率（SRa）对CRT疗效的影响。方法　回顾性选取2015年5月-2018年1月因心力衰竭于中国科学技术大学附属第一医院心内科行CRT的患者共121例。CRT有反应定义为CRT术后6个月左心室收缩末期容积（LVESV）缩小≥15%，反之为无反应。根据CRT疗效将患者分为有反应组和无反应组。CRT术前和术后6个月应用二维斑点追踪技术评价左心房Sa和SRa，评价基线左心房Sa和SRa对CRT疗效的影响。结果　CRT术后共有70例（57.9%）患者纳入有反应组，51例（42.1%）患者纳入无反应组。有反应组术后6个月Sa和SRa较术前明显改善（P<0.05）。Spearman秩相关分析显示Sa与SRa呈负相关（rs=-0.770，P<0.001）。多因素Logistic回归分析显示SRa（OR=5.039，P=0.020）和Sa（OR=1.094，P=0.010）是CRT疗效的影响因素，其他影响因素包括左束支传导阻滞（OR=4.913，P=0.002）、QRS时限（OR=1.041，P=0.005）、E/A（OR=0.309，P=0.008）和肺动脉收缩压（OR=0.950，P=0.013）。结论　基线Sa和SRa是CRT疗效的独立预测因素，CRT术后有反应者左心房收缩功能改善。

Relationship of Left Atrial Systolic Strain and Strain Rate Evaluated by Two-dimensional Speckle Tracking in Cardiac Resynchronization Therapy

Background　Left atrial function is an important component of cardiac function.Studies have shown that left atrial volume can independently affect the efficacy of cardiac resynchronization therapy（CRT）.Objective　In this study，two-dimensional speckle tracking technique was used to quantitatively assess left atrial function and evaluate its effect on the outcome of CRT.The research was meant to evaluate the influence of left atrial strain（Sa） and strain rate（SRa） during atrial contraction on the efficacy of CRT.Methods　A total of 121 patients who underwent CRT implantation in Cardiovascular Department，the First Affiliated Hospital of USTC due to heart failure between May 2015 and January 2018 were selected retrospectively.Two-dimensional speckle-tracing technique was used to evaluate the Sa and SRa of left atrial.CRT response was defined as a reduction of LVESV by at least 15% within six months after surgery.Patients were divided into response group and non-response group by efficacy of CRT.Pre- and post-surgery left atrial Sa and SRa were compared，and relationships of the two with the efficacy of CRT were evaluated.Results　51 patients（42.1%）showed no response to CRT.In other 70 patients（57.9%） with response to CRT，both left atrial Sa and SRa improved significantly at six months after surgery（P<0.05）.The Spearman's rank correlation coefficient between Sa and SRa was -0.770（P<0.001）.Both SRa（OR=5.039，P=0.020） and Sa（OR=1.094，P=0.010）were factors influencing on the efficacy of CRT according to multivariate Logistic regression analysis.Other influencing factors included left bundle branch block（OR=4.913，P=0.002），QRS duration（OR=1.041，P=0.005），E/A ratio（OR=0.309，P=0.008），and pulmonary artery systolic pressure（OR=0.950，P=0.013）.Conclusion　Baseline Sa and SRa were independent predictors of CRT responsiveness.Left atrial systolic function improved significantly in those with response to implantation of CRT.