title: Absence of left ventricular apical rocking and atrial-ventricular dyssynchrony predicts non-response to cardiac resynchronization therapy.
abstract: OBJECTIVE
  Current imaging techniques attempt to identify responders to cardiac resynchronization therapy (CRT). However, because CRT response may depend upon several factors, it may be clinically more useful to identify patients for whom CRT would not be beneficial even under optimal conditions. We aimed to determine the negative predictive value of a composite echocardiographic index evaluating atrial-ventricular dyssynchrony (AV-DYS) and intraventricular dyssynchrony.
  
  
  RESULTS
  Subjects with standard indications for CRT underwent echo before and during the month following device implantation. AV-DYS was defined as a percentage of left ventricular (LV) filling time over the cardiac cycle. AV-DYS, which produces a characteristic rocking of the LV apex, was quantified as the percentage of the cardiac cycle over which tissue Doppler-derived displacement curves of the septal and lateral walls showed discordance. CRT responder status was determined based on the early haemodynamic response to CRT (intra-individual improvement >25% in the Doppler-derived LV dP/dt). Among 40 patients, optimal cut-points predicting CRT response were 31% for LV apical rocking and 39% for AV-DYS. The presence of either apical rocking >31% or AV-DYS ≤ 39% had a sensitivity of 95%, specificity of 80%, positive predictive value of 83%, and a negative predictive value of 94% for CRT response.
  
  
  CONCLUSIONS
  After pre-selection of candidates for CRT by QRS duration, application of a simple composite echocardiographic index may exclude patients who would be non-responders to CRT and thus improve the global rate of therapy success.
authors.affiliation: Cardiology Division, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA. francois.tournoux@cardiopixel.com
authors.forename: François
authors.initials: F
authors.lastname: Tournoux
authors.forename: Jagmeet P
authors.initials: JP
authors.lastname: Singh
authors.forename: Raymond C
authors.initials: RC
authors.lastname: Chan
authors.forename: Annabel
authors.initials: A
authors.lastname: Chen-Tournoux
authors.forename: David
authors.initials: D
authors.lastname: McCarty
authors.forename: Robert
authors.initials: R
authors.lastname: Manzke
authors.forename: Jeremy N
authors.initials: JN
authors.lastname: Ruskin
authors.forename: Marc
authors.initials: M
authors.lastname: Semigran
authors.forename: E Kevin
authors.initials: EK
authors.lastname: Heist
authors.forename: Stephanie
authors.initials: S
authors.lastname: Moore
authors.forename: Michael H
authors.initials: MH
authors.lastname: Picard
authors.forename: Arthur E
authors.initials: AE
authors.lastname: Weyman
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D058406:Cardiac Resynchronization Therapy / Q000379:methods*; D005260:Female; D006305:Health Status Indicators; D006325:Heart Atria / Q000000981:diagnostic imaging* / Q000473:pathology; D006333:Heart Failure / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy; D006352:Heart Ventricles / Q000000981:diagnostic imaging* / Q000473:pathology; D006801:Humans; D008297:Male; D011237:Predictive Value of Tests; D011379:Prognosis; D012680:Sensitivity and Specificity; D016896:Treatment Outcome; D018608:Ultrasonography, Doppler / Q000379:methods; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy