title: Comparison of quick optimization of interventricular delay between simple methods: intracardiac electrogram and surface electrocardiogram after cardiac resynchronization therapy.
abstract: OBJECTIVE
  It is time consuming to obtain optimal interventricular (VV) delay by conventional methods. This study is designed to compare quick optimization between intracardiac electrogram (IEGM) with surface electrocardiogram (ECG)-guided VV delay optimization for cardiac resynchronization therapy (CRT).
  
  
  RESULTS
  Fifty-one heart failure patients (M/F = 34/17, age = 71 ± 10-year-old) scheduled for CRT implantation were included. After atrioventricular optimization, VV delay optimization was performed by either the IEGM or surface ECG method. Aortic velocity time integral (AVTI) was used  as a reference in comparing these two methods. Real-time three-dimensional echocardiography was studied under three varying parameters-CRT switched off or CRT switched on, and VV delay optimized by IEGM guided or surface ECG. The AVTI could be improved equally by either IEGM-guided or surface ECG-guided VV optimization. All the other parameters [QRS width, systolic dyssynchrony index (SDI), left ventricular ejection fraction (LVEF), left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV)] could be improved by either the IEGM or ECG method in these patients. In the multivariate logistic regression analysis, the immediate improvement of acute LVEF was independently related to favourable outcomes (odds ratio 1.23, 95% CI = 1.03-1.47, P = 0.02).
  
  
  CONCLUSIONS
  The AVTI, QRS width, SDI, LVEF, LVEDV, and LVESV could be improved equally by either IEGM-guided or surface ECG-guided method after CRT.
authors.affiliation: Division of Cardiology, Department of Medicine, Fong Yuan Hospital, Taiwan.
authors.forename: Chien-Ming
authors.initials: CM
authors.lastname: Cheng
authors.forename: Jin-Long
authors.initials: JL
authors.lastname: Huang
authors.forename: Tsu-Juey
authors.initials: TJ
authors.lastname: Wu
authors.forename: Chieh-Shou
authors.initials: CS
authors.lastname: Su
authors.forename: Hsi-Yen
authors.initials: HY
authors.lastname: Pai
authors.forename: Mau-Fang
authors.initials: MF
authors.lastname: Liao
authors.forename: Chih-Tai
authors.initials: CT
authors.lastname: Ting
authors.forename: Shih-Ann
authors.initials: SA
authors.lastname: Chen
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D018780:Body Surface Potential Mapping / Q000379:methods*; D058406:Cardiac Resynchronization Therapy; D019560:Echocardiography, Three-Dimensional / Q000379:methods; D022062:Electrophysiologic Techniques, Cardiac / Q000379:methods*; D005260:Female; D006333:Heart Failure / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy; D006801:Humans; D008297:Male; D012189:Retrospective Studies; D013318:Stroke Volume / Q000502:physiology; D016896:Treatment Outcome