title: Left ventricular mechanics during right ventricular apical or left ventricular-based pacing in patients with chronic atrial fibrillation after atrioventricular junction ablation.
abstract: OBJECTIVE
  The aim of the study was to evaluate whether left ventricular (LV) mechanics are better under LV-based pacing than under right ventricular (RV) apical pacing in patients with permanent atrial fibrillation (AF) after atrioventricular junction (AVJ) ablation.
  
  
  BACKGROUND
  "Ablate and pace" is an acceptable therapy for drug-refractory AF. However, the RV apical stimulation commonly used seems to interfere with the beneficial hemodynamic effect of regularization of heart rhythm.
  
  
  METHODS
  The study included 12 patients (5 men, mean age 62 +/- 8.3 years), 6 with impaired and 6 with normal LV systolic function. All of them had a biventricular pacemaker system implanted and underwent atrioventricular node ablation for drug-refractory chronic AF. Using a conductance catheter, we analyzed LV pressure-volume loops during routine coronary angiography in order to evaluate short-term changes in LV mechanics during RV apical and LV-based (LV free wall or biventricular) pacing.
  
  
  RESULTS
  Compared with RV pacing, LV-based pacing significantly improved the indexes of LV systolic function (i.e., end-systolic pressure and volume, cardiac index, stroke work, preload recruitable stroke work, maximal rate of rise of LV pressure [dP/dt(max)], LV ejection fraction, and end-systolic elastance). The LV diastolic filling indexes, end-diastolic pressure and volume, were better during LV-based pacing, whereas LV diastolic function indexes, -dP/dt(max), passive diastolic chamber stiffness, and time constant of LV isovolumic relaxation showed no clear change.
  
  
  CONCLUSIONS
  In the short term, LV-based pacing is superior to RV apical pacing in terms of contractile function and LV filling after AVJ ablation for drug-refractory AF.
authors.affiliation: Cardiology Department, Heraklion University Hospital, PO Box 1352 Stavrakia, Heraklion, Crete, Greece.
authors.forename: Emmanuel N
authors.initials: EN
authors.lastname: Simantirakis
authors.forename: Konstantinos E
authors.initials: KE
authors.lastname: Vardakis
authors.forename: George E
authors.initials: GE
authors.lastname: Kochiadakis
authors.forename: Emmanuel G
authors.initials: EG
authors.lastname: Manios
authors.forename: Nikolaos E
authors.initials: NE
authors.lastname: Igoumenidis
authors.forename: Michele
authors.initials: M
authors.lastname: Brignole
authors.forename: Panos E
authors.initials: PE
authors.lastname: Vardas
mesh_terms: D001281:Atrial Fibrillation / Q000601:surgery / Q000628:therapy*; D001283:Atrioventricular Node / Q000601:surgery; D002304:Cardiac Pacing, Artificial; D017115:Catheter Ablation / Q000379:methods*; D002908:Chronic Disease; D004452:Echocardiography; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008944:Mitral Valve Insufficiency / Q000000981:diagnostic imaging / Q000503:physiopathology; D013318:Stroke Volume; D016896:Treatment Outcome