title: Combined identification of septal flash and absence of myocardial scar by cardiac magnetic resonance imaging improves prediction of response to cardiac resynchronization therapy.
abstract: Septal flash (SF) describes early inward motion of the ventricular septum in patients with left bundle branch block (LBBB), and correction corresponds to increased response to cardiac resynchronization therapy (CRT). SF has traditionally been assessed by echocardiography. We sought to determine if cardiac magnetic resonance (CMR) imaging could identify SF and if the additional assessment of scar would improve the ability of CMR to predict CRT response.
  
  
  METHODS
  Fifty-two patients with LBBB and heart failure underwent prospective CMR scanning prior to CRT implantation. The presence of SF was assessed visually and by using endocardial contour-tracking software. Presence and extent of myocardial scar was assessed by delayed enhancement imaging during CMR. The association between SF, scar and reverse remodelling (RR) at 6 months was explored.
  
  
  RESULTS
  RR rate to CRT at 6 months was 52%. CMR-derived SF was identified in 24 (46%) patients. RR was seen in more patients with SF than those without (88% vs 21%; P < 0.001). The absence of scar combined with the presence of SF had 96% specificity for predicting RR. In a multivariate regression model, the presence of SF was the only independent predictor of RR.
  
  
  CONCLUSIONS
  SF can be assessed by CMR and predicts increased response to CRT. The additional value of CMR is the assessment of scar. The presence of SF with no scar is a highly specific predictor of CRT response.
authors.affiliation: Division of Imaging Sciences and Biomedical Engineering, King's College London, London, UK, manav.sohal@gstt.nhs.uk.
authors.forename: Manav
authors.initials: M
authors.lastname: Sohal
authors.forename: Sana
authors.initials: S
authors.lastname: Amraoui
authors.forename: Zhong
authors.initials: Z
authors.lastname: Chen
authors.forename: Eva
authors.initials: E
authors.lastname: Sammut
authors.forename: Tom
authors.initials: T
authors.lastname: Jackson
authors.forename: Matthew
authors.initials: M
authors.lastname: Wright
authors.forename: Mark
authors.initials: M
authors.lastname: O'Neill
authors.forename: Jaswinder
authors.initials: J
authors.lastname: Gill
authors.forename: Gerald
authors.initials: G
authors.lastname: Carr-White
authors.forename: C Aldo
authors.initials: CA
authors.lastname: Rinaldi
authors.forename: Reza
authors.initials: R
authors.lastname: Razavi
mesh_terms: D002037:Bundle-Branch Block / Q000401:mortality* / Q000628:therapy*; D058406:Cardiac Resynchronization Therapy / Q000401:mortality*; D002921:Cicatrix / Q000401:mortality* / Q000473:pathology*; D015897:Comorbidity; D005260:Female; D006346:Heart Septum / Q000473:pathology*; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care / Q000379:methods; D015995:Prevalence; D011379:Prognosis; D015203:Reproducibility of Results; D012307:Risk Factors; D012680:Sensitivity and Specificity; D015996:Survival Rate; D016896:Treatment Outcome; D006113:United Kingdom / Q000453:epidemiology