title: Reverse cardiac remodeling after renal denervation: Atrial electrophysiologic and structural changes associated with blood pressure lowering.
abstract: BACKGROUND
  Hypertension is the most common modifiable risk factor associated with atrial fibrillation.
  
  
  OBJECTIVE
  The purpose of this study was to determine the effects of blood pressure (BP) lowering after renal denervation on atrial electrophysiologic and structural remodeling in humans.
  
  
  METHODS
  Fourteen patients (mean age 64 ± 9 years, duration of hypertension 16 ± 11 years, on 5 ± 2 antihypertensive medications) with treatment-resistant hypertension underwent baseline 24-hour ambulatory BP monitoring, echocardiography, cardiac magnetic resonance imaging, and electrophysiologic study. Electrophysiologic study included measurements of P-wave duration, effective refractory periods, and conduction times. Electroanatomic mapping of the right atrium was completed using CARTO3 to determine local and regional conduction velocity and tissue voltage. Bilateral renal denervation was performed, and all measurements repeated after 6 months.
  
  
  RESULTS
  After renal denervation, mean 24-hour BP reduced from 152/84 mm Hg to 141/80 mm Hg at 6-month follow-up (P < .01). Global conduction velocity increased significantly (0.98 ± 0.13 m/s to 1.2 ± 0.16 m/s at 6 months, P < .01), conduction time shortened (32 ± 5 ms to 27 ± 6 ms, P < .01), and complex fractionated activity was reduced (37% ± 14% to 19% ± 12%, P = .02). Changes in conduction velocity correlated positively with changes in 24-hour mean systolic BP (R(2) = 0.55, P = .01). There was a significant reduction in left ventricular mass (139 ± 37 g to 120 ± 29 g, P < .01) and diffuse ventricular fibrosis (T1 partition coefficient 0.39 ± 0.07 to 0.31 ± 0.09, P = .01) on cardiac magnetic resonance imaging.
  
  
  CONCLUSIONS
  BP reduction after renal denervation is associated with improvements in regional and global atrial conduction and reductions in ventricular mass and fibrosis. Whether changes in electrical and structural remodeling are solely due to BP lowering or are due in part to intrinsic effects of renal denervation remains to be determined.
authors: Department of Cardiovascular Medicine, Alfred Hospital, Melbourne, Victoria, Australia; Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia; Cardiology Department, Royal Melbourne Hospital, Victoria, Australia; Faculty of Medicine, Dentistry, and Health Sciences, University of Melbourne, Victoria, Australia.
authors: Alex J A
authors: AJ
authors: McLellan
authors: Department of Cardiovascular Medicine, Alfred Hospital, Melbourne, Victoria, Australia; Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia; Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne, Australia; School of Medicine and Pharmacology-Royal Perth Hospital Campus, University of Western Australia, Perth, Australia.
authors: Markus P
authors: MP
authors: Schlaich
authors: Department of Cardiovascular Medicine, Alfred Hospital, Melbourne, Victoria, Australia; Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia.
authors: Andrew J
authors: AJ
authors: Taylor
authors: Department of Cardiovascular Medicine, Alfred Hospital, Melbourne, Victoria, Australia; Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia; Cardiology Department, Royal Melbourne Hospital, Victoria, Australia; Faculty of Medicine, Dentistry, and Health Sciences, University of Melbourne, Victoria, Australia.
authors: Sandeep
authors: S
authors: Prabhu
authors: Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia.
authors: Dagmara
authors: D
authors: Hering
authors: Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia.
authors: Louise
authors: L
authors: Hammond
authors: Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia.
authors: Petra
authors: P
authors: Marusic
authors: Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia.
authors: Jacqueline
authors: J
authors: Duval
authors: Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia.
authors: Yusuke
authors: Y
authors: Sata
authors: Department of Cardiovascular Medicine, Alfred Hospital, Melbourne, Victoria, Australia; Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia.
authors: Andris
authors: A
authors: Ellims
authors: Department of Cardiovascular Medicine, Alfred Hospital, Melbourne, Victoria, Australia; Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia; Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne, Australia.
authors: Murray
authors: M
authors: Esler
authors: Department of Cardiovascular Medicine, Alfred Hospital, Melbourne, Victoria, Australia; Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia.
authors: Karlheinz
authors: K
authors: Peter
authors: Department of Cardiovascular Medicine, Alfred Hospital, Melbourne, Victoria, Australia; Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia.
authors: James
authors: J
authors: Shaw
authors: Department of Cardiovascular Medicine, Alfred Hospital, Melbourne, Victoria, Australia; Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia.
authors: Antony
authors: A
authors: Walton
authors: Cardiology Department, Royal Melbourne Hospital, Victoria, Australia; Faculty of Medicine, Dentistry, and Health Sciences, University of Melbourne, Victoria, Australia.
authors: Jonathan M
authors: JM
authors: Kalman
authors: Department of Cardiovascular Medicine, Alfred Hospital, Melbourne, Victoria, Australia; Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia; Cardiology Department, Royal Melbourne Hospital, Victoria, Australia; Faculty of Medicine, Dentistry, and Health Sciences, University of Melbourne, Victoria, Australia. Electronic address: peter.kistler@bakeridi.edu.au.
authors: Peter M
authors: PM
authors: Kistler
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000209:etiology / Q000503:physiopathology; D064752:Atrial Remodeling / Q000502:physiology*; D001794:Blood Pressure / Q000502:physiology; D003714:Denervation / Q000379:methods*; D022062:Electrophysiologic Techniques, Cardiac / Q000379:methods; D005260:Female; D006325:Heart Atria / Q000503:physiopathology; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000503:physiopathology / Q000601:surgery; D007668:Kidney / Q000294:innervation*; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D008875:Middle Aged; D016896:Treatment Outcome
keywords: Atrial fibrillation; Cardiac magnetic resonance imaging; Electrophysiologic study; Remodeling; Renal denervation