title: Discrepancy between electrical and mechanical dyssynchrony in patients with heart failure and an electrical disturbance.
abstract: BACKGROUND
  Cardiac resynchronization therapy (CRT) improves the survival rates of patients with heart failure, but 30-40% of them do not respond to CRT, partially because of the position of the left ventricular (LV) lead. The relationship between the electrical and mechanical activation of the left ventricle is unknown. The aim of this study was to compare the electrical and mechanical dyssynchrony.
  
  
  METHODS
  We inserted electrode catheters into the coronary sinus (CS) and venous branches of the CS during CRT implantations and constructed electroanatomical contact maps in 16 patients using the EnSite NavX™ system. Mechanical activation was evaluated by speckle-tracking echocardiography and the latest mechanical and electrical sites were compared. The degrees of the electrical and mechanical delays of the implanted LV lead were also compared.
  
  
  RESULTS
  The electroanatomical maps revealed that the latest electrical sites were anterior in one, anterolateral in five, lateral in eight, and posterolateral in two. Echocardiographic imaging revealed that the latest mechanical sites were anteroseptal in two, anterior in four, lateral in five, posterior in two, and inferior in three. The latest electrical and mechanical sites matched in only three patients. The degree of the local mechanical delay for the LV lead was significantly larger in the responders than nonresponders, whereas the local electrical delay did not differ.
  
  
  CONCLUSIONS
  A discrepancy between the electrical and mechanical dyssynchrony might affect an adequate LV lead positioning.
authors.affiliation: Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Ryudo
authors.initials: R
authors.lastname: Fujiwara
authors.forename: Akihiro
authors.initials: A
authors.lastname: Yoshida
authors.forename: Koji
authors.initials: K
authors.lastname: Fukuzawa
authors.forename: Asumi
authors.initials: A
authors.lastname: Takei
authors.forename: Kunihiko
authors.initials: K
authors.lastname: Kiuchi
authors.forename: Mitsuaki
authors.initials: M
authors.lastname: Itoh
authors.forename: Kimitake
authors.initials: K
authors.lastname: Imamura
authors.forename: Atsushi
authors.initials: A
authors.lastname: Suzuki
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Nakanishi
authors.forename: Soichiro
authors.initials: S
authors.lastname: Yamashita
authors.forename: Akinori
authors.initials: A
authors.lastname: Matsumoto
authors.forename: Hidekazu
authors.initials: H
authors.lastname: Tanaka
authors.forename: Ken-Ichi
authors.initials: K
authors.lastname: Hirata
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D058406:Cardiac Resynchronization Therapy / Q000379:methods*; D003937:Diagnosis, Differential; D004567:Electrodes, Implanted; D005260:Female; D006333:Heart Failure / Q000175:diagnosis* / Q000209:etiology / Q000517:prevention & control*; D006801:Humans; D008297:Male; D008875:Middle Aged; D019919:Prosthesis Implantation / Q000379:methods; D017180:Tachycardia, Ventricular / Q000150:complications / Q000175:diagnosis* / Q000517:prevention & control*; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000150:complications / Q000175:diagnosis* / Q000517:prevention & control*
keywords: cardiac resynchronization therapy; dyssynchrony; electrical delay; mechanical delay