title: Easy-to-use comprehensive speckle-tracking approach for cardiac resynchronization therapy.
abstract: BACKGROUND
  Left ventricular (LV) dyssynchrony has emerged as an important mechanism contributing to the patient's response to cardiac resynchronization therapy (CRT), but other potential factors, especially LV myocardial viability, are also influential. METHODS AND RESULTS: We studied 132 patients undergoing CRT. LV dyssynchrony was determined by anteroseptal-to-posterior wall delay on the mid-LV short-axis view using 2-dimensional speckle-tracking radial strain (≥130 ms as significant). Global circumferential strain (GCS), considered as a parameter of LV intrinsic myocardial function, was also determined as the peak GCS from the same view. Long-term follow-up was tracked over 40 months. Kaplan-Meier analysis indicated that patients with GCS >3.9% experienced fewer cardiovascular events overall (log-rank P=0.034). Similarly, patients with GCS >3.9% and ≥6.6% experienced fewer cardiovascular events than those with GCS ≤3.9% and <6.6% among patients with and without LV dyssynchrony (log-rank P=0.025 and P=0.029, respectively). An important finding from multivariate Cox proportional hazards analysis was that LV dyssynchrony and GCS were independently associated with cardiovascular events. Of note, only 2±1 min per patient were needed to analyze both LV dyssynchrony and GCS from the same routine mid-LV short-axis view.
  
  
  CONCLUSIONS
  This easy-to-use combined assessment of LV dyssynchrony and myocardial function using speckle-tracking strain from the same mid-LV short-axis view may well have clinical implications for CRT.
authors.affiliation: Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine.
authors.forename: Yasuhide
authors.initials: Y
authors.lastname: Mochizuki
authors.forename: Hidekazu
authors.initials: H
authors.lastname: Tanaka
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Tatsumi
authors.forename: Kensuke
authors.initials: K
authors.lastname: Matsumoto
authors.forename: Junichi
authors.initials: J
authors.lastname: Imanishi
authors.forename: Akihiro
authors.initials: A
authors.lastname: Yoshida
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Yokoyama
authors.forename: Hiroya
authors.initials: H
authors.lastname: Kawai
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Hirata
mesh_terms: D000368:Aged; D001145:Arrhythmias, Cardiac / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy; D058406:Cardiac Resynchronization Therapy; D004452:Echocardiography; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy