title: Multi-site left ventricular pacing as a potential treatment for patients with postero-lateral scar: insights from cardiac magnetic resonance imaging and invasive haemodynamic assessment.
abstract: OBJECTIVE
  Multi-site left ventricular (LV) pacing may be superior to single-site stimulation in correcting dyssynchrony and avoiding areas of myocardial scar. We sought to characterize myocardial scar using cardiac magnetic resonance imaging (CMR). We aimed to quantify the acute haemodynamic response to single-site and multi-site LV stimulation and to relate this to the position of the LV leads in relation to myocardial scar.
  
  
  METHODS
  Twenty patients undergoing cardiac resynchronization therapy had implantation of two LV leads. One lead (LV1) was positioned in a postero-lateral vein, the second (LV2) in a separate coronary vein. LV dP/dtmax was recorded using a pressure wire during stimulation at LV1, LV2, and both sites simultaneously (LV1 + 2). Patients were deemed acute responders if ΔLV dP/dtmax was ≥ 10%. Cardiac magnetic resonance imaging was performed to assess dyssynchrony as well as location and burden of scar. Scar anatomy was registered with fluoroscopy to assess LV lead position in relation to scar.
  
  
  RESULTS
  LV dP/dtmax increased from 726 ± 161 mmHg/s in intrinsic rhythm to 912 ± 234 mmHg/s with LV1, 837 ± 188 mmHg/s with LV2, and 932 ± 201 mmHg/s with LV1 and LV2. Nine of 19 (47%) were acute responders with LV1 vs. 6/19 (32%) with LV2. Twelve of 19 (63%) were acute responders with simultaneous LV1 + 2. Two of three patients benefitting with multi-site pacing had the LV1 lead positioned in postero-lateral scar.
  
  
  CONCLUSIONS
  Multi-site LV pacing increased acute response by 16% vs. single-site pacing. This was particularly beneficial in patients with postero-lateral scar identified on CMR.
authors: St. Thomas' Hospital, London, UK. m.ginks@btinternet.com
authors: Matthew R
authors: MR
authors: Ginks
authors: Simon G
authors: SG
authors: Duckett
authors: Stamatis
authors: S
authors: Kapetanakis
authors: Julian
authors: J
authors: Bostock
authors: Shoaib
authors: S
authors: Hamid
authors: Anoop
authors: A
authors: Shetty
authors: Yingliang
authors: Y
authors: Ma
authors: Kawal S
authors: KS
authors: Rhode
authors: Gerald S
authors: GS
authors: Carr-White
authors: Reza S
authors: RS
authors: Razavi
authors: C Aldo
authors: CA
authors: Rinaldi
mesh_terms: D000368:Aged; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D005260:Female; D006333:Heart Failure / Q000628:therapy*; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology / Q000628:therapy