title: The prevalence of apical wall motion abnormalities in patients with long-term right ventricular apical pacing.
abstract: BACKGROUND
  Long-term right ventricular apical pacing (RVAP) can lead to adverse clinical outcomes. Although left ventricular (LV) dyssynchrony is the major causative factor, other potential mechanisms are not fully understood. We sought to clarify whether RVAP elicits apical wall motion abnormalities that contribute to LV contractile dysfunction.
  
  
  METHODS
  We studied annual echocardiographic data over a 5-year period after pacemaker implantation (PMI) for 74 patients who underwent RVAP. The patients were divided into two groups according to the percentage of ventricular pacing: right ventricular (RV) pacing < 50% and RV pacing ≥ 50%. We assessed LV ejection fraction, LV end-diastolic volume, and left atrial dimension. To assess regional wall motion abnormalities, the wall motion score index was calculated.
  
  
  RESULTS
  LV wall motion abnormality was observed in 64% of the subjects and was more pronounced in apical segments than in other segments. At 2 years after PMI, brain natriuretic peptide levels were significantly higher in the group with RV pacing ≥ 50% than in the group with RV pacing < 50%. The subjects with RV pacing ≥ 50% had higher LV end-diastolic dimension and lower ejection fraction at 3 years after PMI.
  
  
  CONCLUSIONS
  Long-term RVAP elicits apical wall motion abnormalities that could in part contribute to LV contractile dysfunction.
authors.affiliation: Department of Cardiovascular Medicine, Akita University Graduate School of Medicine, Akita, Japan.
authors.forename: Takako
authors.initials: T
authors.lastname: Sato-Iino
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Watanabe
authors.forename: Takashi
authors.initials: T
authors.lastname: Koyama
authors.forename: Kenji
authors.initials: K
authors.lastname: Iino
authors.forename: Toshimitsu
authors.initials: T
authors.lastname: Kosaka
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ito
mesh_terms: D000368:Aged; D005260:Female; D006325:Heart Atria / Q000000981:diagnostic imaging / Q000473:pathology*; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000473:pathology*; D006801:Humans; D008297:Male; D020097:Natriuretic Peptide, Brain; D015995:Prevalence; D012189:Retrospective Studies; D012804:Sick Sinus Syndrome / Q000097:blood / Q000000981:diagnostic imaging / Q000473:pathology; D018709:Statistics, Nonparametric; D013318:Stroke Volume; D013997:Time Factors; D014463:Ultrasonography; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging / Q000473:pathology*; D018497:Ventricular Dysfunction, Right / Q000000981:diagnostic imaging / Q000473:pathology*; D016277:Ventricular Function, Left
chemical_list: D020097:Natriuretic Peptide, Brain