Real-time three-dimensional echocardiography for determining right ventricular stroke volume in an animal model of chronic right ventricular volume overload.
BACKGROUND
The lack of a suitable noninvasive method for assessing right ventricular (RV) volume and function has been a major deficiency of two-dimensional (2D) echocardiography. The aim of our animal study was to test a new real-time three-dimensional (3D) echo imaging system for evaluating RV stroke volumes.


RESULTS
Three to 6 months before hemodynamic and 3D ultrasonic study, the pulmonary valve was excised from 6 sheep (31 to 59 kg) to induce RV volume overload. At the subsequent session, a total of 14 different steady-state hemodynamic conditions were studied. Electromagnetic (EM) flow probes were used for obtaining aortic and pulmonic flows. A unique phased-array volumetric 3D imaging system developed at the Duke University Center for Emerging Cardiovascular Technology was used for ultrasonic imaging. Real-time volumetric images of the RV were digitally stored, and RV stroke volumes were determined by use of parallel slices of the 3D RV data set and subtraction of end-systolic cavity volumes from end-diastolic cavity volumes. Multiple regression analyses showed a good correlation and agreement between the EM-obtained RV stroke volumes (range, 16 to 42 mL/beat) and those obtained by the new real-time 3D method (r=0.80; mean difference, -2.7+/-6.4 mL/beat).


CONCLUSIONS
The real-time 3D system provided good estimation of strictly quantified reference RV stroke volumes, suggesting an important application of this new 3D method.
Shiota
T
T
Oregon Health Sciences University, Portland 97201-3098, USA.
Jones
M
M
Chikada
M
M
Fleishman
C E
CE
Castellucci
J B
JB
Cotter
B
B
DeMaria
A N
AN
von Ramm
O T
OT
Kisslo
J
J
Ryan
T
T
Sahn
D J
DJ
D000818:Animals; D019560:Echocardiography, Three-Dimensional; D004574:Electromagnetic Fields; D006439:Hemodynamics; D006801:Humans; D015588:Observer Variation; D012044:Regression Analysis; D015203:Reproducibility of Results; D012756:Sheep; D013318:Stroke Volume; D018497:Ventricular Dysfunction, Right / Q000000981:diagnostic imaging / Q000503:physiopathology*; D016278:Ventricular Function, Right