title: Assessment of Left Ventricular Dissipative Energy Loss by Vector Flow Mapping in Patients With End-Stage Renal Disease.
abstract: OBJECTIVE
  Dissipative energy loss derived from vector flow mapping represents the viscous dissipation of turbulent blood flow. We aimed to determine the left ventricular (LV) energy loss in patients with end-stage renal disease (ESRD).
  
  
  METHODS
  Patients with ESRD and a preserved LV ejection fraction, who consisted of a group receiving peritoneal dialysis, a group receiving hemodialysis, and a group receiving preparation for dialysis initiation, were examined by echocardiography; a group of healthy control participants were examined as well. Vector flow mapping analysis was then performed from the apical 4-chamber view to calculate the energy loss during diastole and systole in the left ventricle.
  
  
  RESULTS
  Conventional transthoracic echocardiography and LV energy loss calculations were successfully performed in 63 cases and 50 controls. The patients with ESRD had significantly higher diastolic energy loss [median (interquartile range), 71.73 (46.08-106.75) versus 23.32 (17.17-29.26) mW/m; P < .001] and higher systolic energy loss [25.28 (19.03-33.93) versus 12.52 (9.35-16.47) mW/m; P < .001]. A significant difference in diastolic energy loss between the peritoneal dialysis and preparation groups was found [54.92 (39.28-89.94) versus 84.82 (62.58-171.4) mW/m; P = .04]. In patients with ESRD, the log-transformed diastolic energy loss had a significant association with the peak early diastolic transmitral flow velocity (P = .011), peak early diastolic transmitral flow velocity-to-peak early diastolic mitral annular flow velocity ratio (P = .001), LV mass index (P = .017), and heart rate (P = .003).
  
  
  CONCLUSIONS
  Impaired blood flow efficiency was detected in patients with ESRD by using dissipative energy loss derived from vector flow mapping. The energy loss value could be a novel parameter for evaluating the ventricular workload of uremic hearts in terms of fluid mechanics.
authors.affiliation: Department of Cardiology, West China Hospital of Sichuan University, Chengdu, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Zhong
authors.affiliation: Department of Cardiology, West China Hospital of Sichuan University, Chengdu, China.
authors.forename: Yanting
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Cardiology, West China Hospital of Sichuan University, Chengdu, China.
authors.forename: Ting
authors.initials: T
authors.lastname: Wu
authors.affiliation: Department of Cardiology, West China Hospital of Sichuan University, Chengdu, China.
authors.forename: Huizi
authors.initials: H
authors.lastname: Song
authors.affiliation: Department of Cardiology, West China Hospital of Sichuan University, Chengdu, China.
authors.forename: Zhongxiu
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Department of Cardiology, West China Hospital of Sichuan University, Chengdu, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhu
authors.affiliation: Department of Cardiology, West China Hospital of Sichuan University, Chengdu, China.
authors.forename: Yuyan
authors.initials: Y
authors.lastname: Cai
authors.affiliation: Department of Cardiology, West China Hospital of Sichuan University, Chengdu, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Department of Cardiology, West China Hospital of Sichuan University, Chengdu, China.
authors.forename: Wenjuan
authors.initials: W
authors.lastname: Bai
authors.affiliation: Department of Cardiology, West China Hospital of Sichuan University, Chengdu, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Tang
authors.affiliation: Department of Cardiology, West China Hospital of Sichuan University, Chengdu, China. lrlz1989@163.com.
authors.forename: Li
authors.initials: L
authors.lastname: Rao
mesh_terms: D000328:Adult; D000368:Aged; D001783:Blood Flow Velocity; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D007676:Kidney Failure, Chronic / Q000150:complications / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D014672:Vectorcardiography / Q000379:methods*; D018487:Ventricular Dysfunction, Left / Q000150:complications / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D055815:Young Adult
keywords: dissipative energy loss; echocardiography; end-stage renal disease; vector flow mapping