title: Time course of left ventricular volumes in severe congestive heart failure patients treated by optimized AV sequential left ventricular pacing alone--a 3-dimensional echocardiographic study.
abstract: BACKGROUND
  This study evaluates the acute and chronic resynchronizing effects of AV sequential left ventricular (LV) pacing on LV function in patients with impaired cardiac function and conduction disorders by 3-dimensional transesophageal echocardiography.
  
  
  RESULTS
  Twenty-nine patients with congestive heart failure, with LV ejection fraction (LVEF) < or = 30%, QRS duration > or = 120 milliseconds, and New York Heart Association Class II to IV, were implanted with a cardiac resynchronization device using an LV lead only, according to the invasively determined hemodynamic optimal pacing site and AV delay. Patients underwent 3-dimensional transesophageal echocardiography before randomization to treatment (baseline) and at 12-month follow-up (resynchronization--12 months). Three-dimensional volumes were acquired on resynchronization and during intermittent switch-off at intrinsic depolarization. The values of stroke volume were 43.2 +/- 13.3 (intrinsic-baseline), 51.7 +/- 17.4 (intrinsic--12 months), 57.2 +/- 15.6 (resynchronization-baseline), and 64.6 +/- 18.9 (resynchronization--12 months). Analysis of variance demonstrated a significant effect of resynchronization at different periods (P < .001) and a significant time effect (P < .05) for stroke volume. Similar results were observed with ejection fraction (LVEF). No effect was observed with LV end-diastolic volume, whereas a therapy effect with no time effect was observed with LV end-systolic volume.
  
  
  CONCLUSIONS
  A significant acute increase of LV stroke volume and LVEF was found by resynchronization by LV pacing alone. A continuous improvement of LV stroke volume and LVEF occurred with time of follow-up (reverse remodeling). The initial therapeutic effect persisted during 12-month follow-up independently of time of follow-up and QRS width. No significant decrease of LV end-diastolic size during chronic resynchronization was detected in contrast to previous studies with resynchronization by biventricular pacing.
authors.affiliation: German Heart Institute, Berlin, Germany. c.butter@immanuel.de
authors.forename: Christian
authors.initials: C
authors.lastname: Butter
authors.forename: Ernst
authors.initials: E
authors.lastname: Wellnhofer
authors.forename: Martin
authors.initials: M
authors.lastname: Seifert
authors.forename: Michael
authors.initials: M
authors.lastname: Schlegl
authors.forename: Walter
authors.initials: W
authors.lastname: Hoersch
authors.forename: Alexander
authors.initials: A
authors.lastname: Goehring
authors.forename: Eckart
authors.initials: E
authors.lastname: Fleck
mesh_terms: D002304:Cardiac Pacing, Artificial; D019560:Echocardiography, Three-Dimensional; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy*; D006352:Heart Ventricles / Q000000981:diagnostic imaging* / Q000473:pathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D013997:Time Factors