title: Characterization of left ventricle energy loss in healthy adults using vector flow mapping: Preliminary results.
abstract: BACKGROUND
  Energy loss (EL) is a new quantitative hemodynamic index based on vector flow mapping (VFM). This study aimed to characterize EL of the left ventricle (LV) in healthy adults.
  
  
  METHODS
  Fifty-one healthy adults were enrolled in this study. EL of LV was analyzed frame by frame using color Doppler images of a standard apical three-chamber dynamic view on an offline VFM workstation. The average EL of systole and diastole was calculated, and the results were averaged over three cardiac cycles.
  
  
  RESULTS
  The average EL for systole and diastole was 11.07±5.82J/m/s and 11.58±5.54 J/m/s, respectively. Multivariate regression analysis showed that the aortic velocity time integral (AOVTI), A-wave peak velocity, and isovolumetric contraction time (IVCT) were independently associated with the average systolic EL. E-wave peak velocity, height, and IVCT were independently associated with the average diastolic EL. For females, the average systolic and diastolic EL was 12.66±7.06J/m/s and 13.90±5.37J/m/s, respectively. For males, the systolic and diastolic EL was 9.29±3.33J/m/s and 8.97±4.55J/m/s, respectively.
  
  
  CONCLUSIONS
  Energy loss in LV changes regularly during the cardiac cycle. The average systolic EL has a high positive correlation with AOVTI, whereas the average diastolic EL has with E-wave peak velocity. Women have higher average EL than men in both systole and diastole. By recognizing the EL characterization of healthy adults, the variation in EL may reflect cardiac dysfunction. These were preliminary results, and thus, the clinical implications of EL warrant further investigation.
authors.affiliation: Ultrasound Department, Xijing Hospital, Xi'an, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Xu
authors.affiliation: Ultrasound Department, Xijing Hospital, Xi'an, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Sun
authors.affiliation: Ultrasound Department, Xijing Hospital, Xi'an, China.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Zhu
authors.affiliation: Ultrasound Department, Xijing Hospital, Xi'an, China.|Ultrasound Department, The Third Hospital of People's Liberation Army, Bao Ji, China.
authors.forename: Weihua
authors.initials: W
authors.lastname: Liu
authors.affiliation: Ultrasound Department, Xijing Hospital, Xi'an, China.|Ultrasound Department, Yan'an People's Hospital, Yan'an, China.
authors.forename: Shengjun
authors.initials: S
authors.lastname: Ta
authors.affiliation: Ultrasound Department, Xijing Hospital, Xi'an, China.|Ultrasound Department, Ningxia Medical University, Yin Chuan, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Zhao
authors.affiliation: Ultrasound Department, Xijing Hospital, Xi'an, China.
authors.forename: Feifei
authors.initials: F
authors.lastname: Wang
authors.affiliation: Ultrasound Department, Xijing Hospital, Xi'an, China.
authors.forename: Liwen
authors.identifier: http://orcid.org/0000-0001-9838-5727
authors.initials: L
authors.lastname: Liu
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity / Q000502:physiology*; D004452:Echocardiography / Q000379:methods; D004735:Energy Transfer / Q000502:physiology; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D009200:Myocardial Contraction / Q000502:physiology*; D010865:Pilot Projects; D012016:Reference Values; D012212:Rheology / Q000379:methods*; D013318:Stroke Volume / Q000502:physiology*; D016277:Ventricular Function, Left / Q000502:physiology*
keywords: energy loss; healthy adult; left ventricle; vector flow mapping