Echocardiographic mapping of left ventricular resynchronization during cardiac resynchronization therapy procedures

• Published in: Chinese medical journal 2010-07, Vol.123 (13), p.1645-1651
• Main Authors: Chan, Ngai-Yin, Choy, Chi-Chung, Cheung, Kar-Chun, Lau, Chun-Leung, Lo, Ying-Keung, Chu, Pui-Shan, Yuen, Ho-Chuen, Lau, Suet-Ting, Choi, Yuen-Choi
• Format: Article
• Language: English
• Subjects: Aged; Cardiac Resynchronization Therapy - methods; Echocardiography - methods; Female; Heart Failure - therapy; Humans; Male; Middle Aged; Ventricular Dysfunction, Left - therapy; 再同步; 左心室; 心力衰竭; 超声心动图; 边值问题
• ISSN: 0366-6999; 2542-5641
• DOI: 10.3760/cma.j.issn.0366-6999.2010.13.006

Background Cardiac resynchronization therapy （CRT） is an effective electrical therapy for patients with moderate to severe heart failure and cardiac dyssynchrony. This study aimed to investigate the degree of acute left ventricular （LV） resynchronization with biventricular pacing （BVP） at different LV sites and to examine the feasibility of performing transthoracic echocardiography （TTE） to quantify acute LV resynchronization during CRT procedure. Methods Fourteen patients with NYHA Class Ⅲ-Ⅳ heart failure, LV ejection fraction 〈35%, QRS duration 〉120 ms and septal-lateral delay （SLD） 〉60 ms on tissue Doppler imaging （TDI）, underwent CRT implant. TDI was obtained from three apical views during BVP at each accessible LV site and SLD during BVP was derived. Synchronicity gain index （Sg） by SLD was defined as （I＋（SLD at baseline - SLD at BVP）/SLD at baseline）. Results Seventy-two sites were studied. Positive resynchronization （R＋, Sg〉1） was found in 42 （58%） sites. R＋ was more likely in posterior or lateral than anterior LV sites （66% vs. 36%, P 〈0.001）. Concordance of empirical LV lead implantation sites and sites with R＋ was 50% （7/14）. Conclusions The degree of acute LV resynchronizaUon by BVP depends on LV lead location and empirical implantation of LV lead results in only 50% concordance with R＋. Performing l-rE during CRT implantation is feasible to identify LV sites with positive resynchronization.