title: Effect of chronic right ventricular apical pacing on left ventricular function.
abstract: The determinants of change in left ventricular (LV) ejection fraction (EF) over time in patients with impaired LV function at baseline have not been clearly established. Using a nuclear database to assess changes in LV function over time, we included patients with a baseline LVEF of 25% to 40% on a gated single-photon emission computed tomographic study at rest and only if second-gated photon emission computed tomography performed approximately 18 months after the initial study showed an improvement in LVEF at rest of > or =10 points or a decrease in LVEF at rest of > or =7 points. In all, 148 patients qualified for the EF increase group and 59 patients for the EF decrease group. LVEF on average increased from 33 +/- 4% to 51 +/- 8% in the EF increase group and decreased from 35 +/- 4% to 25 +/- 5% in the EF decrease group. The strongest multivariable predictor of improvement of LVEF was beta-blocker therapy (odds ratio 3.9, p = 0.002). The strongest independent predictor of LVEF decrease was the presence of a permanent right ventricular apical pacemaker (odds ratio 6.6, p = 0.002). Thus, this study identified beta-blocker therapy as the major independent predictor for improvement in LVEF of > or =10 points, whereas a permanent pacemaker (right ventricular apical pacing) was the strongest predictor of a LVEF decrease of > or =7 points.
authors.affiliation: Mid-America Heart Institute, Kansas City, Missouri 64111, USA. jhokeefe@cc-pc.com
authors.forename: James H
authors.initials: JH
authors.lastname: O'Keefe
authors.forename: Hussam
authors.initials: H
authors.lastname: Abuissa
authors.forename: Philip G
authors.initials: PG
authors.lastname: Jones
authors.forename: Randall C
authors.initials: RC
authors.lastname: Thompson
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Bateman
authors.forename: A Iain
authors.initials: AI
authors.lastname: McGhie
authors.forename: Brian M
authors.initials: BM
authors.lastname: Ramza
authors.forename: David M
authors.initials: DM
authors.lastname: Steinhaus
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D000368:Aged; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D002908:Chronic Disease; D003131:Combined Modality Therapy; D018450:Disease Progression; D005080:Exercise Test; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010138:Pacemaker, Artificial; D012189:Retrospective Studies; D013223:Statistics as Topic; D013318:Stroke Volume / Q000187:drug effects / Q000502:physiology*; D015899:Tomography, Emission-Computed, Single-Photon; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D016278:Ventricular Function, Right / Q000187:drug effects / Q000502:physiology*
chemical_list: D000319:Adrenergic beta-Antagonists; D000806:Angiotensin-Converting Enzyme Inhibitors