title: Echocardiography versus intracardiac electrocardiography-based optimization for cardiac resynchronization therapy : a comparative clinical long-term trial.
abstract: BACKGROUND
  Optimization of AV and VV delay programming has been shown to be essential for the success of cardiac resynchronization therapy (CRT). Acute hemodynamic improvement can be obtained by intracardiac electrocardiogram (IEGM)-based optimization. The aim of the present study was to evaluate whether this IEGM-based algorithm is comparable to the current gold standard of echocardiography.
  
  
  METHODS
  After device implantation patients with standard criteria for CRT, AV and VV delay programming was either optimized by an IEGM-based algorithm (IEGM group, n = 24) or by echocardiography (echo group, n = 24). Cardiopulmonary exercise capacity was assessed after 3 and 12 months on the basis of NYHA class and the 6-min-walk test. Left ventricular ejection fraction was evaluated by echocardiography.
  
  
  RESULTS
  In both groups there was a significant decrease in NYHA class and a significant increase in 6-min-walk distance and ejection fraction after 3 and 12 months. After 12 months there was no significant difference in the proportion of responders, NYHA class and 6-min-walk distance between the IEGM the echo group.
  
  
  CONCLUSIONS
  The present data show that a sustained improvement of cardiopulmonary exercise capacity can be obtained by optimizing CRT patients on the basis of an IEGM algorithm. The comparable results for cardiopulmonary exercise parameters suggest that this new method might become an important tool for adjusting CRT programming in daily practice.
authors.affiliation: Department of Cardiology and Angiology, Elisabeth Hospital Essen, Germany.
authors.forename: C J
authors.initials: CJ
authors.lastname: Jensen
authors.forename: A
authors.initials: A
authors.lastname: Liadski
authors.forename: M
authors.initials: M
authors.lastname: Bell
authors.forename: C K
authors.initials: CK
authors.lastname: Naber
authors.forename: O
authors.initials: O
authors.lastname: Bruder
authors.forename: G V
authors.initials: GV
authors.lastname: Sabin
authors.forename: B
authors.initials: B
authors.lastname: Küpper
authors.forename: H
authors.initials: H
authors.lastname: Wieneke
mesh_terms: D000368:Aged; D000465:Algorithms; D002037:Bundle-Branch Block / Q000401:mortality / Q000503:physiopathology / Q000628:therapy; D058406:Cardiac Resynchronization Therapy / Q000379:methods*; D058409:Cardiac Resynchronization Therapy Devices; D004452:Echocardiography / Q000295:instrumentation / Q000379:methods*; D004562:Electrocardiography / Q000295:instrumentation / Q000379:methods*; D004567:Electrodes, Implanted; D004867:Equipment Design; D005080:Exercise Test; D005260:Female; D005500:Follow-Up Studies; D006325:Heart Atria / Q000503:physiopathology; D006333:Heart Failure / Q000401:mortality / Q000503:physiopathology / Q000628:therapy*; D006352:Heart Ventricles / Q000503:physiopathology; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation; D012984:Software; D015996:Survival Rate; D016896:Treatment Outcome