title: Assessment of apical rocking: a new, integrative approach for selection of candidates for cardiac resynchronization therapy.
abstract: OBJECTIVE
  Current attempts of improving patient selection in cardiac resynchronization therapy (CRT) are mainly based on echocardiographic timing of myocardial velocity peaks. Regional myocardial function is neglected. Apical transverse motion (ATM) is a new parameter to quantify apical rocking as an integrative surrogate of both temporal and functional inhomogeneities within the left ventricle. In this study, we tested the predictive value of apical rocking for response to CRT.
  
  
  RESULTS
  Sixty-nine patients eligible for CRT were assessed by echocardiography before and 11 ± 5 months after pacemaker implantation. Response was defined as left ventricular (LV) end-systolic volume decrease >15%. Rocking was quantified (ATM) and visually assessed by four blinded readers. Predictive value for CRT response of both assessments was compared with conventional dyssynchrony parameters. ATM in the four-chamber view plane differentiated best between responders and non-responders (2.2 ± 1.5 vs. 0.06 ± 1.9 mm, P< 0.0001). Quantified ATM predicted reverse remodelling with a sensitivity, specificity, and accuracy of 75, 96, and 83% whereas visual rocking assessment resulted in 89, 75, and 83%, respectively. The accuracy of conventional parameters was significantly lower.
  
  
  CONCLUSIONS
  Apical rocking is a new marker to assess LV dyssynchrony and predict CRT response. It is superior to conventional parameters. Even its simple visual assessment may be sufficiently accurate in the clinical setting.
authors.affiliation: Department of Cardiovascular Diseases, University Hospital Gasthuisberg, Catholic University Leuven, Herestraat 49, 3000 Leuven, Belgium.
authors.forename: Mariola
authors.initials: M
authors.lastname: Szulik
authors.forename: Monique
authors.initials: M
authors.lastname: Tillekaerts
authors.forename: Vanessa
authors.initials: V
authors.lastname: Vangeel
authors.forename: Javier
authors.initials: J
authors.lastname: Ganame
authors.forename: Rik
authors.initials: R
authors.lastname: Willems
authors.forename: Radoslaw
authors.initials: R
authors.lastname: Lenarczyk
authors.forename: Frank
authors.initials: F
authors.lastname: Rademakers
authors.forename: Zbigniew
authors.initials: Z
authors.lastname: Kalarus
authors.forename: Tomasz
authors.initials: T
authors.lastname: Kukulski
authors.forename: Jens-Uwe
authors.initials: JU
authors.lastname: Voigt
mesh_terms: D019540:Area Under Curve; D002304:Cardiac Pacing, Artificial; D016009:Chi-Square Distribution; D015150:Echocardiography, Doppler; D005260:Female; D006333:Heart Failure / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000502:physiology; D018579:Patient Selection; D012372:ROC Curve; D012680:Sensitivity and Specificity