title: Effect of transcatheter aortic valve replacement on P-wave duration, P-wave dispersion and left atrial size.
abstract: BACKGROUND
  P-wave dispersion (PWD), a measure of heterogeneity of atrial refractoriness, is defined as the difference between the maximum and minimum P-wave duration. In patients with severe aortic stenosis (AS), P-wave duration and PWD were shown to be increased, indicating atrial electrical remodeling. However, the effect of transcatheter aortic valve replacement (TAVR) on P-wave morphology has not been established yet. The aim of this study is to assess the short and long-term effects of TAVR with two types of bioprosthetic valves on P-wave duration and PWD in association with left atrial (LA) size.
  
  
  METHODS
  Fifty-two (36 female) eligible patients in sinus rhythm who underwent transfemoral TAVR between June 01, 2012 and July 31, 2014 with either a Medtronic CoreValve (MCV) (n = 32) or an Edwards SAPIEN XT Valve (n = 20) were enrolled. Standard 12-lead electrocardiogram and echocardiographic evaluations were performed pre-procedurally, post-TAVR day one and 6 months post-TAVR. P-wave duration and PWD were measured and correlation analyses with echocardiographic variables were performed.
  
  
  RESULTS
  P-wave duration and PWD were significantly decreased on post-TAVR day one (P < 0.05). They continued to decrease during the six month follow-up period, but were not significantly different from short-term values (P > 0.05). The decrease of LA diameter was found significant at the sixth-months of follow-up (P < 0.05). These changes were independent from the types of bioprosthetic valves implanted (P > 0.05). A positive correlation was detected between minimum P-wave duration and maximum aortic valve gradients at post-TAVR day one (r = 0.297, P = 0.032).
  
  
  CONCLUSIONS
  P-wave duration and PWD were significantly reduced early after TAVR indicating early reverse atrial electrical remodeling. Moreover, structural reverse remodeling of atrium was detected at the 6-months of follow-up. The effects of two types of bioprosthetic valves on atrial remodeling were similar.
authors.affiliation: Department of Cardiology, Faculty of Medicine, Dokuz Eylul University, Izmir, Turkey.
authors.forename: Huseyin
authors.initials: H
authors.lastname: Dursun
authors.affiliation: Clinic of Cardiology, Idil State Hospital, Sirnak, Turkey.
authors.forename: Zulkif
authors.initials: Z
authors.lastname: Tanriverdi
authors.affiliation: Department of Cardiology, Faculty of Medicine, Dokuz Eylul University, Izmir, Turkey.
authors.forename: Tugce
authors.initials: T
authors.lastname: Colluoglu
authors.affiliation: Department of Cardiology, Faculty of Medicine, Dokuz Eylul University, Izmir, Turkey.
authors.forename: Dayimi
authors.initials: D
authors.lastname: Kaya
keywords: Aortic stenosis; P-wave dispersion; Transcatheter aortic valve replacement