title: Validation of noninvasive indices of global systolic function in patients with normal and abnormal loading conditions: a simultaneous echocardiography pressure-volume catheterization study.
abstract: BACKGROUND
  Noninvasive indices based on Doppler echocardiography are increasingly used in clinical cardiovascular research to evaluate left ventricular global systolic chamber function. Our objectives were to clinically validate ultrasound-based methods of global systolic chamber function to account for differences between patients in conditions of abnormal load, and to assess their sensitivity to load confounders.
  
  
  RESULTS
  Twenty-seven patients (8 dilated cardiomyopathy, 10 normal ejection fraction, and 9 end-stage liver disease) underwent simultaneous echocardiography and left heart catheterization with pressure-conductance instrumentation. The reference index, maximal elastance (Emax), was calculated from pressure-volume loop data obtained during acute inferior vena cava occlusion. A wide range of values were observed for left ventricular systolic chamber function (Emax: 2.8±1.0 mm Hg/mL), preload, and afterload. Among the noninvasive indices tested, the peak ejection intraventricular pressure difference showed the best correlation with Emax (R=0.75). A significant but weaker correlation with Emax was observed for ejection fraction (R=0.41), midwall fractional shortening (R=0.51), global circumferential strain (R=-0.53), and strain rate (R=-0.46). Longitudinal strain and strain rate failed to correlate with Emax, as did noninvasive single-beat estimations of this index. Principal component and multiple regression analyses demonstrated that peak ejection intraventricular pressure difference was less sensitive to load, whereas ejection fraction and longitudinal strain and strain rate were heavily influenced by afterload.
  
  
  CONCLUSIONS
  Current ultrasound methods have limited accuracy to characterize global left ventricular systolic chamber function in a given patient. The Doppler-derived peak ejection intraventricular pressure difference should be preferred for this purpose because it best correlates with the reference index and is more robust in conditions of abnormal load.
authors.affiliation: Departments of Cardiology.
authors.forename: Raquel
authors.initials: R
authors.lastname: Yotti
authors.forename: Javier
authors.initials: J
authors.lastname: Bermejo
authors.forename: Yolanda
authors.initials: Y
authors.lastname: Benito
authors.forename: Ricardo
authors.initials: R
authors.lastname: Sanz-Ruiz
authors.forename: Cristina
authors.initials: C
authors.lastname: Ripoll
authors.forename: Pablo
authors.initials: P
authors.lastname: Martínez-Legazpi
authors.forename: Candelas Pérez
authors.initials: CP
authors.lastname: del Villar
authors.forename: Jaime
authors.initials: J
authors.lastname: Elízaga
authors.forename: Ana
authors.initials: A
authors.lastname: González-Mansilla
authors.forename: Alicia
authors.initials: A
authors.lastname: Barrio
authors.forename: Rafael
authors.initials: R
authors.lastname: Bañares
authors.forename: Francisco
authors.initials: F
authors.lastname: Fernández-Avilés
mesh_terms: D000368:Aged; D006328:Cardiac Catheterization; D002311:Cardiomyopathy, Dilated / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000503:physiopathology; D015150:Echocardiography, Doppler; D005260:Female; D006333:Heart Failure / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D016014:Linear Models; D008103:Liver Cirrhosis / Q000000981:diagnostic imaging / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D025341:Principal Component Analysis; D015203:Reproducibility of Results; D013318:Stroke Volume; D013599:Systole; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000503:physiopathology; D016277:Ventricular Function, Left; D017725:Ventricular Pressure
keywords: cardiac catheterization; echocardiography; hemodynamics; systole