Effect of chronic right ventricular apical pacing on left ventricular function.
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.
O'Keefe
James H
JH
Mid-America Heart Institute, Kansas City, Missouri 64111, USA. jhokeefe@cc-pc.com
Abuissa
Hussam
H
Jones
Philip G
PG
Thompson
Randall C
RC
Bateman
Timothy M
TM
McGhie
A Iain
AI
Ramza
Brian M
BM
Steinhaus
David M
DM
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*
D000319:Adrenergic beta-Antagonists; D000806:Angiotensin-Converting Enzyme Inhibitors