title: Dependency of cardiac resynchronization therapy on myocardial viability at the LV lead position.
abstract: OBJECTIVE
  This study sought to analyze the effectiveness of cardiac resynchronization therapy (CRT) related to the viability in the segment of left ventricular (LV) lead position defined by myocardial deformation imaging.
  
  
  BACKGROUND
  Echocardiographic myocardial deformation analysis allows determination of LV lead position as well as extent of myocardial viability.
  
  
  METHODS
  Myocardial deformation imaging based on tracking of acoustic markers within 2-dimensional echo images (GE Ultrasound, GE Healthcare, Horton, Norway) was performed in 65 heart failure patients (54 ± 6 years of age, 41 men) before and 12 months after CRT implantation. In a 16-segment model, the LV lead position was defined based on the segmental strain curve with earliest peak strain, whereas the CRT system was programmed to pure LV pacing. Nonviability of a segment (transmural scar formation) was assumed if the peak systolic circumferential strain was >-11.1%.
  
  
  RESULTS
  In 47 patients, the LV lead was placed in a viable segment, and in 18 patients, it was placed in a nonviable segment. At 12-month follow-up there was greater decrease of LV end-diastolic volumes (58 ± 13 ml vs. 44 ± 12 ml, p = 0.0388) and greater increase of LV ejection fraction (11 ± 4% vs. 5 ± 4%, p = 0.0343) and peak oxygen consumption (2.5 ± 0.9 ml/kg/min vs. 1.7 ± 1.1 ml/kg/min, p = 0.0465) in the viable compared with the nonviable group. The change in LV ejection fraction and the reduction in LV end-diastolic volumes at follow-up correlated to an increasing peak systolic circumferential strain in the segment of the LV pacing lead (r = 0.61, p = 0.0274 and r = 0.64, p = 0.0412, respectively). Considering only patients with ischemic heart disease, differences between viable and nonviable LV lead position group were even greater.
  
  
  CONCLUSIONS
  Preserved viability in the segment of the CRT LV lead position results in greater LV reverse remodeling and functional benefit at 12-month follow-up. Deformation imaging allows analysis of viability in the LV lead segment.
authors.affiliation: Department of Cardiology, RWTH Aachen University, Aachen, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Becker
authors.forename: Christian
authors.initials: C
authors.lastname: Zwicker
authors.forename: Markus
authors.initials: M
authors.lastname: Kaminski
authors.forename: Andreas
authors.initials: A
authors.lastname: Napp
authors.forename: Ertunc
authors.initials: E
authors.lastname: Altiok
authors.forename: Christina
authors.initials: C
authors.lastname: Ocklenburg
authors.forename: Zvi
authors.initials: Z
authors.lastname: Friedman
authors.forename: Dan
authors.initials: D
authors.lastname: Adam
authors.forename: Patrick
authors.initials: P
authors.lastname: Schauerte
authors.forename: Nikolaus
authors.initials: N
authors.lastname: Marx
authors.forename: Rainer
authors.initials: R
authors.lastname: Hoffmann
mesh_terms: D058406:Cardiac Resynchronization Therapy; D058409:Cardiac Resynchronization Therapy Devices; D009202:Cardiomyopathies / Q000209:etiology / Q000503:physiopathology; D015150:Echocardiography, Doppler; D004867:Equipment Design; D005260:Female; D005858:Germany; D006333:Heart Failure / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D017202:Myocardial Ischemia / Q000150:complications / Q000503:physiopathology; D009206:Myocardium / Q000473:pathology*; D010101:Oxygen Consumption; D011237:Predictive Value of Tests; D020127:Recovery of Function; D013318:Stroke Volume; D013997:Time Factors; D014022:Tissue Survival; D016896:Treatment Outcome; D016277:Ventricular Function, Left; D020257:Ventricular Remodeling