title: Novel dyssynchrony evaluation by M-mode imaging in left bundle branch block and the application to predict responses for cardiac resynchronization therapy.
abstract: BACKGROUND
  To determine an appropriate M-mode method in assessing left ventricular (LV) dyssynchrony in left bundle branch block (LBBB), and to assess feasibility of the method to predict cardiac resynchronization therapy (CRT) responses.
  
  
  RESULTS
  Fifty-one patients with LBBB were enrolled. Among them 31 patients underwent CRT. In addition to original septal to posterior wall motion delay (SPWMD), first peak-SPWMD was proposed as time of difference between the first septal displacement and the maximum displacement of the posterior. If an early septal point was not present, anatomical M-mode was used to visualize an early septal displacement spreading scan-area until inferoseptal wall. CRT responders were defined as LV end-systolic volume reduction (>15%) at 6 months after CRT. Twenty patients (65%) were identified as CRT responders. First peak-SPWMD in responders was significantly higher than those in nonresponders, although SPWMD did not differ between groups. Strong predicting ability of first peak-SPWMD was revealed (first peak-SPWMD: 80/90/83%; SPWMD: 35/100/58%), and area under the curve in receiver operating characteristic analysis of first peak-SPWMD (0.88) was significantly higher than that of SPWMD (0.61) (p<0.05).
  
  
  CONCLUSIONS
  In patients with LBBB, time differences between early septal and delayed displacement of posterolateral wall on M-mode images were the appropriate dyssynchrony parameter, and could improve the predictive ability for CRT responses.
authors.affiliation: Department of Clinical Laboratory, University of Tsukuba Hospital, Tsukuba, Japan.
authors.forename: Fumiko
authors.initials: F
authors.lastname: Sakamaki
authors.affiliation: Cardiovascular Division, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan. Electronic address: yo-seo@md.tsukuba.ac.jp.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Seo
authors.affiliation: Cardiovascular Division, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Atsumi
authors.affiliation: Cardiovascular Division, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan.
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Yamamoto
authors.affiliation: Cardiovascular Division, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Machino-Ohtsuka
authors.affiliation: Cardiovascular Division, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan.
authors.forename: Ryo
authors.initials: R
authors.lastname: Kawamura
authors.affiliation: Cardiovascular Division, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan.
authors.forename: Hiro
authors.initials: H
authors.lastname: Yamasaki
authors.affiliation: Cardiovascular Division, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan.
authors.forename: Miyako
authors.initials: M
authors.lastname: Igarashi
authors.affiliation: Cardiovascular Division, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan.
authors.forename: Yukio
authors.initials: Y
authors.lastname: Sekiguchi
authors.affiliation: Cardiovascular Division, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Ishizu
authors.affiliation: Cardiovascular Division, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan.
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Aonuma
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002037:Bundle-Branch Block / Q000000981:diagnostic imaging* / Q000628:therapy*; D058406:Cardiac Resynchronization Therapy; D004452:Echocardiography / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D005544:Forecasting; D006801:Humans; D008297:Male; D008875:Middle Aged; D016896:Treatment Outcome
keywords: Cardiac resynchronization therapy; Dyssynchrony; Left bundle branch block; M-mode echocardiography