title: Left ventricular assist improves autonomic imbalance in patients with persistent myocardial dysfunction.
abstract: BACKGROUND
  Left ventricular assist devices (LVAD) are an effective therapeutic option for end-stage heart failure (HF). Reduced heart rate variability (HRV) as a result of autonomic derangement is evident in chronic heart failure and several studies have established the independent prognostic value of HRV in chronic heart failure.
  
  
  OBJECTIVE
  In the present study we investigated whether autonomic function is restored in patients after LVAD implantation with persistent, severely depressed left ventricular function.
  
  
  METHODS
  Ambulatory Holter ECG recordings were collected in heart failure patients with an LVAD (n=8) und age-matched heart failure patients without an LVAD (n=7) both on optimal medical therapy. Cardiac dimensions and function were assessed by echocardiography or angiography.
  
  
  RESULTS
  Analysis for heart rate variability revealed reduced SDNN (67±4 ms), SDANN (56±4 ms) and triangular index (18±1) in heart failure patients on optimal medical therapy. However patients with LVAD demonstrated a restoration in heart rate variability with normal SDNN (108±9 ms), SDANN (103±8 ms) and triangular index (29±2). Compared to patients without LVAD this difference was statistically significant (p<0.01).
  
  
  CONCLUSIONS
  In end-stage heart failure patients autonomic imbalance indicated by severely reduced heart rate variability is restored after LVAD implantation with unloading of the failing heart.
authors.affiliation: Department of Cardiovascular Medicine, Hannover Medical School, Hannover, Germany. gardiwal@gmail.com
authors.forename: Ajmal
authors.initials: A
authors.lastname: Gardiwal
authors.forename: Philipp
authors.initials: P
authors.lastname: Roentgen
authors.forename: Ulrich
authors.initials: U
authors.lastname: Luesebrink
authors.forename: Thorben
authors.initials: T
authors.lastname: Koenig
authors.forename: Gunnar
authors.initials: G
authors.lastname: Klein
authors.forename: Hanno
authors.initials: H
authors.lastname: Oswald
mesh_terms: D000328:Adult; D001341:Autonomic Nervous System / Q000503:physiopathology*; D016022:Case-Control Studies; D002908:Chronic Disease; D015716:Electrocardiography, Ambulatory; D005858:Germany; D006333:Heart Failure / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D006339:Heart Rate; D006352:Heart Ventricles / Q000294:innervation / Q000503:physiopathology*; D006353:Heart-Assist Devices; D006801:Humans; D008875:Middle Aged; D020127:Recovery of Function; D012720:Severity of Illness Index; D013318:Stroke Volume; D013997:Time Factors; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D016277:Ventricular Function, Left