title: His or para-His pacing preserves left ventricular function in atrioventricular block: a double-blind, randomized, crossover study.
abstract: OBJECTIVE
  To compare left ventricular function after a long-term His or para-His pacing (HP) and right ventricular septal pacing (RVSP) in patients with atrioventricular block (AVB).
  
  
  RESULTS
  We included consecutive patients with AVB, a narrow QRS < 120 ms, and a preserved left ventricular ejection fraction (LVEF) >0.40, in a prospective, randomized, double-blinded, crossover design. All patients were treated with 12 months HP and 12 months RVSP. A total of 38 patients [mean age, 67 ± 10 years; 30 (79%) men] were included. The primary endpoint was LVEF, which was significantly lower after a 12 months RVSP (0.50 ± 0.11) than after 12 months of HP (0.55 ± 0.10), P = 0.005. We measured the difference in time-to-peak systolic velocity between opposite basal segments in the apical views by using tissue Doppler imaging. In the four-chamber view, the difference was 58 (±7) ms after RVSP and 49 (±7) ms after HP, P = 0.27; in the two-chamber view, the difference was 45 (±5) ms after RVSP and 31 ±(4) ms after HP, P = 0.02, and in the apical long-axis view, the difference was 63 (±6) after RVSP and 44 (±7) after HP, P = 0.03. There was no difference in New York Heart Association class, 6-min hall walk test, quality-of-life assessments, or device-related complications. The mean threshold was significantly higher in HP leads than in RVSP leads.
  
  
  CONCLUSIONS
  His or para-His pacing preserves LVEF and mechanical synchrony as compared with RVSP after 12 months pacing in patients with AVB, narrow QRS, and LVEF > 0.40.
authors: Department of Cardiology, Aarhus University Hospital, Skejby, Brendstrupgaardsvej 100, DK-8200 Aarhus, Denmark Mads.Brix.Kronborg@ki.au.dk.
authors: Mads B
authors: MB
authors: Kronborg
authors: Department of Cardiology, Aarhus University Hospital, Skejby, Brendstrupgaardsvej 100, DK-8200 Aarhus, Denmark.
authors: Peter T
authors: PT
authors: Mortensen
authors: Department of Cardiology, Aarhus University Hospital, Skejby, Brendstrupgaardsvej 100, DK-8200 Aarhus, Denmark.
authors: Steen H
authors: SH
authors: Poulsen
authors: Department of Cardiology, Aarhus University Hospital, Skejby, Brendstrupgaardsvej 100, DK-8200 Aarhus, Denmark.
authors: Jens C
authors: JC
authors: Gerdes
authors: Department of Cardiology, Aarhus University Hospital, Skejby, Brendstrupgaardsvej 100, DK-8200 Aarhus, Denmark.
authors: Henrik K
authors: HK
authors: Jensen
authors: Department of Cardiology, Aarhus University Hospital, Skejby, Brendstrupgaardsvej 100, DK-8200 Aarhus, Denmark.
authors: Jens C
authors: JC
authors: Nielsen
mesh_terms: D000368:Aged; D054537:Atrioventricular Block / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D002036:Bundle of His / Q000000981:diagnostic imaging / Q000503:physiopathology*; D058406:Cardiac Resynchronization Therapy / Q000009:adverse effects / Q000379:methods*; D058409:Cardiac Resynchronization Therapy Devices; D018592:Cross-Over Studies; D003718:Denmark; D004311:Double-Blind Method; D015150:Echocardiography, Doppler; D004867:Equipment Design; D004868:Equipment Failure; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011788:Quality of Life; D013318:Stroke Volume; D013997:Time Factors; D016896:Treatment Outcome; D016277:Ventricular Function, Left; D016278:Ventricular Function, Right; D054088:Ventricular Septum / Q000503:physiopathology
keywords: Atrioventricular block; His-pacing; Left ventricular function; Pacing