title: A systematic review concerning the relation between the sympathetic nervous system and heart failure with preserved left ventricular ejection fraction.
abstract: BACKGROUND
  Heart failure with preserved left ventricular ejection fraction (HFPEF) affects about half of all patients diagnosed with heart failure. The pathophysiological aspect of this complex disease state has been extensively explored, yet it is still not fully understood. Since the sympathetic nervous system is related to the development of systolic HF, we hypothesized that an increased sympathetic nerve activation (SNA) is also related to the development of HFPEF. This review summarizes the available literature regarding the relation between HFPEF and SNA.
  
  
  RESULTS
  Electronic databases and reference lists through April 2014 were searched resulting in 7722 unique articles. Three authors independently evaluated citation titles and abstracts, resulting in 77 articles reporting about the role of the sympathetic nervous system and HFPEF. Of these 77 articles, 15 were included for critical appraisal: 6 animal and 9 human studies. Based on the critical appraisal, we selected 9 articles (3 animal, 6 human) for further analysis. In all the animal studies, isoproterenol was administered to mimic an increased sympathetic activity. In human studies, different modalities for assessment of sympathetic activity were used. The studies selected for further evaluation reported a clear relation between HFPEF and SNA.
  
  
  CONCLUSIONS
  Current literature confirms a relation between increased SNA and HFPEF. However, current literature is not able to distinguish whether enhanced SNA results in HFPEF, or HFPEF results in enhanced SNA. The most likely setting is a vicious circle in which HFPEF and SNA sustain each other.
authors: Department of Cardiology, University Medical Center Utrecht, Utrecht, the Netherlands.
authors: Willemien L
authors: WL
authors: Verloop
authors: Department of Cardiology, University Medical Center Utrecht, Utrecht, the Netherlands.
authors: Martine M A
authors: MM
authors: Beeftink
authors: Department of Cardiology, University Medical Center Utrecht, Utrecht, the Netherlands.
authors: Bernadet T
authors: BT
authors: Santema
authors: The Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, the Netherlands.
authors: Michiel L
authors: ML
authors: Bots
authors: Department of Nephrology, University Medical Center Utrecht, Utrecht, the Netherlands.
authors: Peter J
authors: PJ
authors: Blankestijn
authors: Department of Cardiology, University Medical Center Utrecht, Utrecht, the Netherlands.
authors: Maarten J
authors: MJ
authors: Cramer
authors: Department of Cardiology, University Medical Center Utrecht, Utrecht, the Netherlands.
authors: Pieter A
authors: PA
authors: Doevendans
authors: Department of Cardiology, University Medical Center Utrecht, Utrecht, the Netherlands.
authors: Michiel
authors: M
authors: Voskuil
mesh_terms: D000818:Animals; D016208:Databases, Factual; D004452:Echocardiography; D006333:Heart Failure / Q000175:diagnosis* / Q000503:physiopathology; D006801:Humans; D013564:Sympathetic Nervous System / Q000503:physiopathology*; D016277:Ventricular Function, Left / Q000502:physiology*