title: Reverse electrophysiologic remodeling after cardiac mechanical unloading for end-stage nonischemic cardiomyopathy.
abstract: BACKGROUND
  Left ventricular assist devices (LVAD)-induced unloading appear to cause reverse cardiac remodeling. However, its effect on arrhythmogenicity is a controversial issue, and prospective data are lacking. We sought to investigate the impact of LVAD-induced unloading on the electrical properties of the failing heart.
  
  
  METHODS
  We prospectively studied the effects of LVAD therapy on QRS, QT, and QTc durations and ventricular arrhythmias from electrocardiograms and 24-hour ambulatory electrocardiograms recorded before and during 6 months of mechanical support in 12 LVAD patients and 7 other patients with advanced nonischemic cardiomyopathy untreated with LVAD.
  
  
  RESULTS
  After 1 week of LVAD support, QTc duration had decreased from 479 ± 79 ms to 411 ± 57 ms (p = 0.037), and QRS duration from 150 ± 46 ms to 134 ± 32 ms (p = 0.029). At 6 months, QTc was found to be 372 ± 56 ms (p = 0.046 versus baseline, 15% shortening) and QRS 118 ± 25 ms (p = 0.028 versus baseline, 11% shortening). A strong correlation was found between QTc shortening and increase in left ventricular ejection fraction and decrease in left ventricular filling pressures. After 2 months of LVAD support, premature ventricular contractions had decreased from 3,507 ± 4,252 to 483 ± 417 in 24 hours (p = 0.043), ventricular couplets from 82 ± 99 to 29 ± 25 in 24 hours (p = 0.05), and ventricular runs from 9 ± 8 to 10 ± 9 (not significant). No patient died suddenly or suffered a symptomatic arrhythmic event during follow-up. No significant electrocardiographic, functional, or hemodynamic change was observed in the 7 patients untreated with LVAD.
  
  
  CONCLUSIONS
  The LVAD support caused progressive shortening of QTc and QRS intervals, consistent with reverse remodeling of the failing heart's electrical properties, accompanied by a decrease in frequency of ventricular arrhythmias.
authors.affiliation: Third Cardiology Department, University of Athens, Athens, Greece.
authors.forename: Stavros G
authors.initials: SG
authors.lastname: Drakos
authors.forename: John V
authors.initials: JV
authors.lastname: Terrovitis
authors.forename: John N
authors.initials: JN
authors.lastname: Nanas
authors.forename: Efstratios I
authors.initials: EI
authors.lastname: Charitos
authors.forename: Argirios S
authors.initials: AS
authors.lastname: Ntalianis
authors.forename: Konstantinos G
authors.initials: KG
authors.lastname: Malliaras
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Diakos
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Koudoumas
authors.forename: Stergios
authors.initials: S
authors.lastname: Theodoropoulos
authors.forename: Magdi H
authors.initials: MH
authors.lastname: Yacoub
authors.forename: Maria I
authors.initials: MI
authors.lastname: Anastasiou-Nana
mesh_terms: D002311:Cardiomyopathy, Dilated / Q000150:complications / Q000503:physiopathology* / Q000601:surgery; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000209:etiology / Q000503:physiopathology* / Q000601:surgery; D006353:Heart-Assist Devices; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D013997:Time Factors; D020257:Ventricular Remodeling / Q000502:physiology*