title: Impact of left ventricular lead position in cardiac resynchronization therapy on left ventricular remodelling. A circumferential strain analysis based on 2D echocardiography.
abstract: OBJECTIVE
  To assess if myocardial deformation imaging allows definition of an optimal left ventricular (LV) lead position with improved effectiveness of cardiac resynchronization therapy (CRT) on LV reverse remodelling.
  
  
  METHODS
  Circumferential strain imaging based on tracking of acoustic markers within 2D echo images (GE Ultrasound) was performed in 47 heart failure patients (59 +/- 9 years, 28 men) at baseline, one day postoperatively, 3 and 10 months after initiation of CRT. Myocardial deformation imaging was used to determine(1) the segment with latest peak negative systolic circumferential strain prior to CRT, and(2) the segment with maximal temporal difference of peak strain before-to-on CRT as the segment with greatest benefit of CRT and assumed LV lead position. Anatomic LV lead position was determined by fluoroscopy. Optimal LV lead position was defined as concordance or immediate neighbouring of the segment with latest systolic strain prior to CRT and segment with assumed LV lead position.
  
  
  RESULTS
  Agreement of assumed LV lead position based on strain analysis and LV lead position defined by fluoroscopy were high (kappa = 0.847). At 10 month follow-up, there was greater increase of EF (12 +/- 3 vs. 7 +/- 4%, P < 0.001), greater decrease of left ventricular end-diastolic volume (LVEDV) (23 +/- 8 vs. 13 +/- 7 mL, P < 0.001) and left ventricular end-systolic volume (LVESV) (42 +/- 10 vs. 27 +/- 8 mL, P < 0.001), and greater increase of VO(2)max (2.8 +/- 0.8 vs. 1.9 +/- 1.0 mL/kg/min, P = 0.035) in the optimal (n = 28 patients) compared to the non-optimal LV lead position group (n = 19 patients). The distance between segment with latest systolic strain prior to CRT and segment with assumed LV lead position was the only independent predictor of DeltaLVEDV and DeltaLVESV at 10 month follow-up (R(2) = 0.2175, P = 0.0197) and (R(2) = 0.3774, P = 0.0054), respectively.
  
  
  CONCLUSIONS
  Detailed analysis of the myocardial contraction sequence using circumferential strain imaging allows determination of the LV lead position in CRT. Optimal LV lead position in CRT defined by circumferential strain analysis results in greater improvement in LV function and more LV reverse remodelling than non-optimal LV lead position.
authors.affiliation: Medical Clinic I, Department of Cardiology, University RWTH Aachen, Pauwelsstrasse 30, 52057 Aachen, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Becker
authors.forename: Rafael
authors.initials: R
authors.lastname: Kramann
authors.forename: Andreas
authors.initials: A
authors.lastname: Franke
authors.forename: Ole-A
authors.initials: OA
authors.lastname: Breithardt
authors.forename: Nicole
authors.initials: N
authors.lastname: Heussen
authors.forename: Christian
authors.initials: C
authors.lastname: Knackstedt
authors.forename: Christoph
authors.initials: C
authors.lastname: Stellbrink
authors.forename: Patrick
authors.initials: P
authors.lastname: Schauerte
authors.forename: Malte
authors.initials: M
authors.lastname: Kelm
authors.forename: Rainer
authors.initials: R
authors.lastname: Hoffmann
mesh_terms: D002304:Cardiac Pacing, Artificial / Q000379:methods*; D004452:Echocardiography; D004566:Electrodes; D005260:Female; D005471:Fluoroscopy; D006333:Heart Failure / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000502:physiology*; D010138:Pacemaker, Artificial; D016896:Treatment Outcome; D016277:Ventricular Function, Left / Q000502:physiology; D020257:Ventricular Remodeling / Q000502:physiology*