title: Combination of real time three-dimensional echocardiography with diagnostic catheterization to derive left ventricular pressure-volume relations.
abstract: OBJECTIVE
  The aim of this study was to investigate the left ventricular (LV) myocardial contractility index-Emax using transesophageal real time three-dimensional echocardiography (RT3DE) combined with catheterization.
  
  
  METHODS
  Transesophageal RT3DE (single beat, X7-2 × matrix, iE33, Philips) was used to obtain real time LV volumes in pigs. Volumes were integrated with LV pressures from conductance catheterization (CC) to create RT3DE pressure-volume relations. At the same time, CC was used for measuring conventional pressure-volume relations that served as reference. The slope Emax was determined from RT3DE and CC end-systolic pressure-volume relations. All measurements were made at rest and during dobutamine infusion.
  
  
  RESULTS
  In six pigs, the mean ± SD (mmHg/mL) values were Emax-CC 1.86 ± 1.1 and Emax-RT3DE 1.78 ± 1.2 (P = 0.502) at baseline. On dobutamine, mean Emax-CC was 3.43 ± 1.5 and Emax-RT3DE 3.60 ± 1.23 (P = 0.171). Bland-Altman analysis showed good agreements between the RT3DE- and CC-derived Emax for measurements performed at baseline and on dobutamine.
  
  
  CONCLUSIONS
  Emax can be determined from RT3DE integrated with catheterization-derived pressures. RT3DE is a promising method for enhancing clinical applicability of pressure-volume relations for assessment of myocardial contractility.
authors.affiliation: Division of Cardiology, University of Nebraska Medical Center and Children's Hospital and Medical Center, Omaha, Nebraska.
authors.forename: Shelby
authors.initials: S
authors.lastname: Kutty
authors.forename: Ling
authors.initials: L
authors.lastname: Li
authors.forename: Asif
authors.initials: A
authors.lastname: Padiyath
authors.forename: Paul
authors.initials: P
authors.lastname: Gribben
authors.forename: Shunji
authors.initials: S
authors.lastname: Gao
authors.forename: John
authors.initials: J
authors.lastname: Lof
authors.forename: Keshore R
authors.initials: KR
authors.lastname: Bidasee
authors.forename: David A
authors.initials: DA
authors.lastname: Danford
authors.forename: Titus
authors.initials: T
authors.lastname: Kuehne
mesh_terms: D000818:Animals; D001794:Blood Pressure; D001795:Blood Pressure Determination / Q000379:methods*; D006328:Cardiac Catheterization / Q000379:methods*; D003199:Computer Systems; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D009200:Myocardial Contraction / Q000502:physiology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013318:Stroke Volume; D013552:Swine; D014463:Ultrasonography; D016277:Ventricular Function, Left / Q000502:physiology*
keywords: catheterization; left ventricle; myocardial contractility; pressure-volume relationship; three-dimensional echocardiography