title: Incidence and predictors of right ventricular pacing-induced cardiomyopathy in patients with complete atrioventricular block and preserved left ventricular systolic function.
abstract: Right ventricular (RV) pacing may worsen left ventricular cardiomyopathy in patients with reduced left ventricular ejection fraction (LVEF) and advanced atrioventricular block.
  
  
  
  The objectives of this study were to calculate incidence and identify predictors of RV pacing-induced cardiomyopathy (PICM) in complete heart block (CHB) with preserved LVEF and to describe outcomes of subsequent cardiac resynchronization therapy (CRT) upgrade.
  
  
  
  An analysis of consecutive patients receiving permanent pacemaker (PPM) from 2000 to 2014 for CHB with LVEF >50% was performed. PICM was defined as CRT upgrade or post-PPM LVEF ≤40%. PICM association was determined via multivariable regression analysis. CRT response was defined by LVEF increase ≥10% or left ventricular end-systolic volume decrease ≥15%.
  
  
  
  Of the 823 study patients, 101 (12.3%) developed PICM over the mean follow-up of 4.3 ± 3.9 years, with post-PPM LVEF being 33.7% ± 7.4% in patients with PICM vs 57.6% ± 6.1% in patients without PICM (P < .001). In multivariable analysis, lower pre-PPM LVEF (hazard ratio [HR] 1.047 per 1% LVEF decrease; 95% confidence interval [CI] 1.002-1.087; P = .042) and RV pacing % both as a continuous (HR 1.011 per 1% RV pacing; 95% CI 1.002-1.02; P = .021) and as a categorical (<20% or ≥20% RV pacing) (HR 6.76; 95% CI 2.08-22.0; P = .002) variable were independently associated with PICM. Only 29 patients with PICM (28.7%) received CRT upgrade despite an 84% responder rate (LVEF increase 18.5% ± 8.1% and left ventricular end-systolic volume decrease 45.1% ± 15.0% in responders). CRT upgrade was associated with greater post-PPM LVEF decrease, lower post-PPM LVEF, and post-PPM LVEF ≤35% (P = .006, P = .004, and P = .004, respectively).
  
  
  
  PICM is not uncommon in patients receiving PPM for CHB with preserved LVEF and is strongly associated with RV pacing burden >20%. CRT response rate is high in PICM, but is perhaps underutilized.
authors.affiliation: Department of Cardiovascular Medicine.
authors.forename: Erich L
authors.initials: EL
authors.lastname: Kiehl
authors.affiliation: Department of Internal Medicine, Cleveland Clinic Foundation, Cleveland, Ohio.
authors.forename: Tarek
authors.initials: T
authors.lastname: Makki
authors.affiliation: Department of Internal Medicine, Cleveland Clinic Foundation, Cleveland, Ohio.
authors.forename: Rahul
authors.initials: R
authors.lastname: Kumar
authors.affiliation: Department of Internal Medicine, Cleveland Clinic Foundation, Cleveland, Ohio.
authors.forename: Divya
authors.initials: D
authors.lastname: Gumber
authors.affiliation: Department of Cardiovascular Medicine, Imaging Section, Cleveland Clinic Foundation, Cleveland, Ohio.
authors.forename: Deborah H
authors.initials: DH
authors.lastname: Kwon
authors.affiliation: Department of Cardiovascular Medicine, Electrophysiology Section, Cleveland Clinic Foundation, Cleveland, Ohio.
authors.forename: John W
authors.initials: JW
authors.lastname: Rickard
authors.affiliation: Department of Cardiovascular Medicine, Electrophysiology Section, Cleveland Clinic Foundation, Cleveland, Ohio.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Kanj
authors.affiliation: Department of Cardiovascular Medicine, Electrophysiology Section, Cleveland Clinic Foundation, Cleveland, Ohio.
authors.forename: Oussama M
authors.initials: OM
authors.lastname: Wazni
authors.affiliation: Department of Cardiovascular Medicine, Electrophysiology Section, Cleveland Clinic Foundation, Cleveland, Ohio.
authors.forename: Walid I
authors.initials: WI
authors.lastname: Saliba
authors.affiliation: Department of Cardiovascular Medicine, Electrophysiology Section, Cleveland Clinic Foundation, Cleveland, Ohio.
authors.forename: Niraj
authors.initials: N
authors.lastname: Varma
authors.affiliation: Department of Cardiovascular Medicine, Electrophysiology Section, Cleveland Clinic Foundation, Cleveland, Ohio.
authors.forename: Bruce L
authors.initials: BL
authors.lastname: Wilkoff
authors.affiliation: Department of Cardiovascular Medicine, Electrophysiology Section, Cleveland Clinic Foundation, Cleveland, Ohio. Electronic address: cantild@ccf.org.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Cantillon
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D054537:Atrioventricular Block / Q000175:diagnosis / Q000628:therapy*; D058406:Cardiac Resynchronization Therapy / Q000009:adverse effects* / Q000379:methods; D009202:Cardiomyopathies / Q000453:epidemiology / Q000209:etiology / Q000503:physiopathology; D004452:Echocardiography / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006352:Heart Ventricles / Q000503:physiopathology; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D014481:United States / Q000453:epidemiology; D016277:Ventricular Function, Left
keywords: Atrioventricular block; Cardiac resynchronization therapy; Cardiomyopathy; Complete heart block; Ejection fraction; Heart failure; Incidence; Pacing; Pacing-induced cardiomyopathy; Predictors