title: Real Time Three-Dimensional Echocardiographic Evaluations of Fetal Left Ventricular Stroke Volume, Mass, and Myocardial Strain: In Vitro and In Vivo Experimental Study.
abstract: BACKGROUND
  Left ventricular stroke volume, mass, and myocardial strain are valuable indicators of fetal heart function. This study investigated the feasibility of nongated real time three-dimensional echocardiography (RT3DE) to determine fetal stroke volume (SV), left ventricular mass (LVM), and myocardial strain under different conditions.
  
  
  METHODS
  To evaluate fetal hearts, fetal-sized rabbit hearts were used in this study. The in vitro portion of this study was carried out using a balloon inserted into the LV of eight fresh rabbit hearts and driven by a calibrated pulsatile pump. RT3DE volumes were obtained at various pump-set SVs. The in vivo experiments in this study were performed on open-chest rabbits. RT3DE volumes were acquired at the following conditions: baseline, simulated hypervolemia, inferior vena cava (IVC) ligation, and ascending aorta (AAO) ligation. Displacement values and sonomicrometry data were used as references for RT3DE-derived SV, LVM, longitudinal strain (LS), and circumferential strain (CS).
  
  
  RESULTS
  Excellent correlations between RT3DE-derived values and reference values were demonstrated and accompanied by high coefficients of determination (R(2) ) for both in vitro and in vivo studies for SV, LVM, LS, and CS (in vitro: SV: R(2)  = 0.98; LVM: R(2)  = 0.97; LS: R(2)  = 0.87, CS: R(2)  = 0.80; in vivo: SV: R(2)  = 0.92; LVM: R(2)  = 0.98; LS: in vivo: R(2)  = 0.84; CS: in vivo: R(2)  = 0.76; all P < 0.05).
  
  
  CONCLUSIONS
  RT3DE is capable of quantifying the SV, LVM, and myocardial strain of fetal-sized hearts under different conditions. This nongated RT3DE may aid the evaluation of fetal cardiac function, providing a superior understanding of the progress of fetal heart disorders.
authors: Oregon Health & Science University, Portland, Oregon.
authors: Meihua
authors: M
authors: Zhu
authors: Oregon Health & Science University, Portland, Oregon.
authors: Muhammad
authors: M
authors: Ashraf
authors: Oregon Health & Science University, Portland, Oregon.
authors: Zhijun
authors: Z
authors: Zhang
authors: Oregon Health & Science University, Portland, Oregon.
authors: Cole
authors: C
authors: Streiff
authors: Oregon Health & Science University, Portland, Oregon.
authors: Eriko
authors: E
authors: Shimada
authors: Oregon Health & Science University, Portland, Oregon.
authors: Sumito
authors: S
authors: Kimura
authors: Oregon Health & Science University, Portland, Oregon.
authors: Traci
authors: T
authors: Schaller
authors: Oregon Health & Science University, Portland, Oregon.
authors: Xubo
authors: X
authors: Song
authors: Oregon Health & Science University, Portland, Oregon.
authors: David J
authors: http://orcid.org/0000-0003-1547-6231
authors: DJ
authors: Sahn
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D019560:Echocardiography, Three-Dimensional; D005260:Female; D005318:Fetal Heart / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D006352:Heart Ventricles / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology*; D066298:In Vitro Techniques; D009929:Organ Size; D011817:Rabbits; D013318:Stroke Volume / Q000502:physiology*; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology
keywords: fetal echocardiography; left ventricular mass, strain; real time imaging technique