title: Left ventricular strain analysis reveals better synchrony and diastolic function for septal versus apical right ventricular permanent pacing.
abstract: OBJECTIVE
  Left ventricular function and synchrony may be altered by right ventricular (RV) apical pacing. Septal pacing might be a better alternative. We compared effects on cardiac synchrony and function, between the 2 pacing sites, in chronically implanted patients.
  
  
  METHODS
  40 pacing-dependent patients (74±9 years, 21 men), 20 paced at the apex, were studied 11±4 months after implantation (baseline); 32 of them were re-examined after 1 year. Systolic function was assessed from ejection fraction (EF), cardiac index (CI), mean longitudinal systolic strain (MLSS), and strain rate (MLSR); diastolic function from E/A, E/E', and E/Vp ratios. Intraventricular dyssynchrony from standard deviation (SSD) and maximal difference (MAXS) of the 12 LV myocardial systolic timings, and sum of all times from the aortic valve closure to peak strain (SUMTAVC) for those segments with post-systolic shortening; interventricular synchrony from the aorto-pulmonary delay (APD).
  
  
  RESULTS
  Four patients died, all of them from the apical group. NYHA functional class was not different. Cardiac synchrony was not significantly different between the two pacing sites at baseline, and after 1 year follow-up. Although at baseline there was a greater dyssynchrony for the septal site, this did not progress at follow-up, whereas this increased for the apical site. Meanwhile, there was a higher LV filling pressure (E/E' ratio) for the apical site at 1 year (13±6 vs.18±6; p=0.04).
  
  
  CONCLUSIONS
  Both septal and apical pacing sites affect negatively LV mechanical activation timings and synchrony. Apical, but not septal site, affects LV synchrony at 1 year, associated with increased filling pressure.
authors.affiliation: "Carol Davila" University of Medicine and Pharmacy, Bucharest, Romania ; Emergency University Hospital, Bucharest, Romania ; "Victor Babes" National Institute, Bucharest, Romania.
authors.forename: Roxana Cristina
authors.initials: RC
authors.lastname: Rimbas
authors.affiliation: "Carol Davila" University of Medicine and Pharmacy, Bucharest, Romania.
authors.forename: Andrei Dumitru
authors.initials: AD
authors.lastname: Margulescu
authors.affiliation: "Carol Davila" University of Medicine and Pharmacy, Bucharest, Romania.
authors.forename: Calin
authors.initials: C
authors.lastname: Siliste
authors.affiliation: "Carol Davila" University of Medicine and Pharmacy, Bucharest, Romania ; Emergency University Hospital, Bucharest, Romania.
authors.forename: Dragos
authors.initials: D
authors.lastname: Vinereanu
keywords: dyssynchrony; left ventricular function; septal pacing