title: Assessment of left ventricular function by pulse wave analysis in critically ill patients.
abstract: OBJECTIVE
  Left ventricular (LV) performance is often quantified by echocardiography in critically ill patients. Pulse wave analysis (PWA) systems can also monitor cardiac function but in a continuous fashion. We compared echocardiographic and PWA-derived indices of LV function.
  
  
  METHODS
  We enrolled 70 critically ill patients equipped with invasive arterial pressure monitoring who required echocardiography. We simultaneously assessed LV ejection fraction (LVEF), the rate of LV pressure rise during systole (dP/dt MAX) obtained with echocardiography (EC-dP/dt MAX), the ratio of effective arterial elastance to LV end-systolic elastance (E a/E es) determined by echocardiography, the dP/dt MAX estimated from the arterial pressure waveform (AP-dP/dt MAX) and the cardiac cycle efficiency (CCE) using PWA.
  
  
  RESULTS
  Mean LVEF was 53 ± 18 % and CCE 0.16 ± 0.26. CCE was correlated linearly with LVEF (r = 0.88, 95 % CI 0.81 to 0.92, P < 0.001), and the dP/dt MAX values from the two techniques were linearly correlated (r = 0.93, 95 % CI 0.87 to 0.96, P < 0.001). There was minimal bias between the techniques for measurement of dP/dt MAX (23.7 mmHg/ms; 95 % CI -23.6 to 71.0). E a/E es and CCE were inversely correlated (r = -0.81, 95 % CI -0.88 to -0.71, P < 0.001). A CCE value of <0.07 predicted LVEF <40 % with a sensitivity of 0.93 and a specificity of 0.96 (AUC 0.98, 95 % CI 0.90 to 1.0, P < 0.001). A CCE value of >0.12 predicted LVEF ≥50 % with a sensitivity of 0.96 and a specificity of 0.82 (AUC 0.94, 95 % CI 0.87 to 1.0, P < 0.001). A CCE value <0.12 predicted E a/E es ≥1.3 with a sensitivity of 0.93 and a specificity of 0.89 (AUC 0.94, 95 % CI 0.83 to 1.0, P < 0.001).
  
  
  CONCLUSIONS
  PWA-derived variables provide relevant information on cardiac contractility and performance in critically ill patients. PWA provides an easy method for online hemodynamic evaluation in critically ill patients.
authors.affiliation: Department of Intensive Care, Erasme University Hospital, Université Libre de Bruxelles, Route de Lennik, 808, 1070 Brussels, Belgium.
authors.forename: Sabino
authors.initials: S
authors.lastname: Scolletta
authors.forename: Laurent
authors.initials: L
authors.lastname: Bodson
authors.forename: Katia
authors.initials: K
authors.lastname: Donadello
authors.forename: Fabio S
authors.initials: FS
authors.lastname: Taccone
authors.forename: Alessandro
authors.initials: A
authors.lastname: Devigili
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Vincent
authors.forename: Daniel
authors.initials: D
authors.lastname: De Backer
mesh_terms: D016638:Critical Illness; D004452:Echocardiography; D005260:Female; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D063177:Pulse Wave Analysis; D012680:Sensitivity and Specificity; D016277:Ventricular Function, Left / Q000502:physiology*