title: Cardiac magnetic resonance-derived anatomy, scar, and dyssynchrony fused with fluoroscopy to guide LV lead placement in cardiac resynchronization therapy: a comparison with acute haemodynamic measures and echocardiographic reverse remodelling.
abstract: OBJECTIVE
  Left ventricular (LV) lead positioning for cardiac resynchronization therapy (CRT) is largely empirical and operator-dependent. Our aim was to determine whether cardiac magnetic resonance (CMR)-guided CRT may improve the acute and the chronic response.
  
  
  RESULTS
  CMR-derived anatomical models and dyssynchrony maps were created for 20 patients. The CMR targets (three latest activated segments with <50% scar) were overlaid on to live fluoroscopy. Acute haemodynamic response (AHR) to LV pacing was assessed using an intra-ventricular pressure wire. Chronic CRT response (end-systolic volume reduction ≥15%) was assessed 6 months post-implantation. All patients underwent successful CMR-guided LV lead placement. A CMR target segment was paced in 75% of patients. The mean change in LVdP/dtmax for the CMR target was +14.2 ± 12.5 vs. +18.7 ± 11.9% for the best AHR in any segment and +12.0 ± 13.8% for the segment based on coronary sinus (CS) venography. Using CMR guidance, the acute responder rate was 60 vs. 50% on the basis of venography. At 6 months 60% of patients were echocardiographic responders. Of the echocardiographic responders, 92% were successfully paced in a CMR target segment compared with only 50% of non-responders (P = 0.04).
  
  
  CONCLUSIONS
  CMR guidance compared well when validated against the AHR. Lead placement was possible in the CMR target region in most patients with an AHR comparable with the best achieved in any CS branch. The chronic response was significantly better in patients paced in a CMR target segment. These results suggest that CMR guidance may represent a clinically useful tool for CRT.
authors.affiliation: Department of Imaging Sciences, Rayne Institute, Kings College London, London, UK.
authors.forename: Anoop K
authors.initials: AK
authors.lastname: Shetty
authors.forename: Simon G
authors.initials: SG
authors.lastname: Duckett
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Ginks
authors.forename: Yinglaing
authors.initials: Y
authors.lastname: Ma
authors.forename: Manav
authors.initials: M
authors.lastname: Sohal
authors.forename: Julian
authors.initials: J
authors.lastname: Bostock
authors.forename: Stam
authors.initials: S
authors.lastname: Kapetanakis
authors.forename: Jagmeet P
authors.initials: JP
authors.lastname: Singh
authors.forename: Kawal
authors.initials: K
authors.lastname: Rhode
authors.forename: Matthew
authors.initials: M
authors.lastname: Wright
authors.forename: Mark D
authors.initials: MD
authors.lastname: O'Neill
authors.forename: Jaswinder S
authors.initials: JS
authors.lastname: Gill
authors.forename: Gerald
authors.initials: G
authors.lastname: Carr-White
authors.forename: Reza
authors.initials: R
authors.lastname: Razavi
authors.forename: Christopher Aldo
authors.initials: CA
authors.lastname: Rinaldi
mesh_terms: D000368:Aged; D000792:Angiography / Q000379:methods; D058406:Cardiac Resynchronization Therapy / Q000379:methods*; D002921:Cicatrix / Q000000981:diagnostic imaging / Q000473:pathology; D015331:Cohort Studies; D018618:Echocardiography, Doppler, Color; D005260:Female; D005471:Fluoroscopy / Q000379:methods; D005500:Follow-Up Studies; D006333:Heart Failure / Q000175:diagnosis / Q000628:therapy*; D006352:Heart Ventricles / Q000033:anatomy & histology*; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods; D008297:Male; D008875:Middle Aged; D008953:Models, Anatomic; D010138:Pacemaker, Artificial; D010690:Phlebography / Q000379:methods; D011446:Prospective Studies; D011930:Reaction Time; D015203:Reproducibility of Results; D012307:Risk Factors; D012720:Severity of Illness Index; D016896:Treatment Outcome; D020257:Ventricular Remodeling / Q000502:physiology*