title: Electrical remodeling and cardiac dimensions in patients treated by cardiac resynchronization and heart failure controls.
abstract: BACKGROUND
  Cardiac resynchronization therapy (CRT) reduces the left ventricular diameter (LVEDD) in heart failure (HF) patients with left bundle branch block (LBBB). The study compares structural and electrical remodeling in HF patients on CRT and matched HF controls without LBBB.
  
  
  METHODS
  In 42 patients (64 +/- 9 years left ventricular ejection fraction [LVEF] 25 +/- 8%, 16 coronary artery disease, 26 nonischemic cardiomyopathy, 21 with LBBB and CRT indication vs 21 controls [matched for gender, age, LVEF, and underlying disease]) an unpaced electrocardiogram (ECG) and echocardiogram were recorded at baseline (bl) and after 20.6 +/- 13.8 months (fup). LVEDD, left atrial (LA) width, mitral regurgitation (MR), P-wave, PR interval, QRS width, QRS vector, and QT interval were analyzed.
  
  
  RESULTS
  LVEDD diminished with CRT (bl 68.7 +/- 10.3 vs fup 62.0 +/- 7.7 mm, P = 0.002). Controls showed no change (bl 64.1 +/- 9.4 vs fup 64.8 +/- 8.4 mm, P = n.s.). MR improved with CRT (bl 1.2 +/- 0.6 vs fup 0.8 +/- 0.7, P = 0.02), but not among controls. LA width tended to decrease on CRT (CRT bl 48.9 +/- 4.4 vs fup 46.9 +/- 7.2 mm, P = 0.17, controls bl 48.5 +/- 5.1 vs fup 47.5 +/- 6.5 mm, P = 0.49). PR interval lengthened in both groups (CRT bl 175 +/- 29 vs fup 188 +/- 30 ms, P = 0.03, controls bl 177+/-25 vs fup 187 +/- 19 ms, P = 0.27). QRS increased in both groups (CRT bl 165 +/- 22 vs fup 171 +/- 20 ms, P = 0.07, controls bl 111 +/- 17 vs fup 118 +/- 19 ms, P = 0.01). Analyses revealed no significant association of echocardiographic and ECG parameters.
  
  
  CONCLUSIONS
  Despite LVEDD reduction with CRT, electrical activation does not recover. Electrical remodeling does not differ between LBBB patients under CRT and matched controls without CRT indication.
authors.affiliation: Charité-Universitaetsmedizin Berlin, Campus Virchow-Klinikum, Medizinische Klinik mit Schwerpunkt Kardiologie, Berlin, Germany. martin.stockburger@charite.de
authors.forename: Martin
authors.initials: M
authors.lastname: Stockburger
authors.forename: Aischa
authors.initials: A
authors.lastname: Nitardy
authors.forename: Suzanne
authors.initials: S
authors.lastname: Fateh-Moghadam
authors.forename: Alice
authors.initials: A
authors.lastname: Krebs
authors.forename: Ozlem
authors.initials: O
authors.lastname: Celebi
authors.forename: Tim
authors.initials: T
authors.lastname: Karhausen
authors.forename: Rainer
authors.initials: R
authors.lastname: Dietz
mesh_terms: D000368:Aged; D002037:Bundle-Branch Block / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D016022:Case-Control Studies; D004452:Echocardiography; D004562:Electrocardiography; D005260:Female; D006333:Heart Failure / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D018709:Statistics, Nonparametric; D020257:Ventricular Remodeling