title: A novel fluoroscopic method of measuring right-to-left interlead distance as a predictor of reverse left ventricular remodeling after cardiac resynchronization therapy.
abstract: OBJECTIVE
  In spite of technological breakthroughs, the choice of a suitable location for the coronary sinus (CS) lead in biventricular implants is still mostly empiric. The aim of this study was to investigate the utility of a radiological index-the distance between the right ventricular (RV) and CS lead tips on fluoroscopic recordings, measured by means of a new method-as a tool for selecting the most profitable left ventricular (LV) lead position.
  
  
  METHODS
  Forty-nine consecutive patients (36 male, 13female; mean age 63 ± 19 year), in whom the LV electrode was implanted in a lateral/postero-lateral position in the CS, were evaluated immediately after implantation. The fluoroscopic distances between the RV and LV lead tips were calculated off-line in antero-posterior (2DAP) and latero-lateral (2DLL) projections by means of integrated software.
  
  
  RESULTS
  On 1-year follow-up evaluation, 53 % patients were classed as responders (R) (>15 % reduction in LV end-systolic volume) and 47 % as non-responders (NR). On receiver-operating curve analysis, 2DAP and 2DLL showed cut-off values of 81 mm and 51 mm, respectively. In discriminating between R and NR, 2DAP >81 mm displayed 95 % specificity and 74 % sensitivity, while 2DLL >51 mm displayed 74 % specificity and 92 % sensitivity. On multivariate analysis, the cut-off values of 2DAP and 2DLL were significantly predictive of R to CRT.
  
  
  CONCLUSIONS
  In our single-center prospective experience, RV-LV interlead distance measured by means of a novel method on fluorographic recordings correlated with CRT response. The use of this method as an intra-operative guide to identifying suitable lead placement in the CS needs evaluating on-line and on a large scale.
authors.affiliation: Servizio di Elettrofisiologia, Ospedale San Giovanni Bosco, Via Filippo Maria Briganti 255, 80100, Napoli, Italy, covino.greg@gmail.com.
authors.forename: Gregorio
authors.initials: G
authors.lastname: Covino
authors.forename: Mario
authors.initials: M
authors.lastname: Volpicelli
authors.forename: Pietro
authors.initials: P
authors.lastname: Belli
authors.forename: Gennaro
authors.initials: G
authors.lastname: Ratti
authors.forename: Paolo
authors.initials: P
authors.lastname: Tammaro
authors.forename: Ciro
authors.initials: C
authors.lastname: Provvisiero
authors.forename: Carmine
authors.initials: C
authors.lastname: Ciardiello
authors.forename: Luca
authors.initials: L
authors.lastname: Auricchio
authors.forename: Ciro
authors.initials: C
authors.lastname: Fiorentino
authors.forename: Paolo
authors.initials: P
authors.lastname: Capogrosso
mesh_terms: D059925:Anatomic Landmarks / Q000000981:diagnostic imaging; D058406:Cardiac Resynchronization Therapy / Q000379:methods*; D005260:Female; D057918:Fiducial Markers; D005471:Fluoroscopy / Q000379:methods*; D006333:Heart Failure / Q000150:complications / Q000000981:diagnostic imaging* / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000209:etiology / Q000628:therapy*