Stroke volume in-vivo using multiple 2D echo views from one echo window

We recently validated in-vitro a new mathematical approach to echocardiographic volume calculation. With this method all echo views are acquired from one point as the transducer is tilted. The angle of tilt of the transducer must be measured. A tilt frame was designed for use in-vivo that does not interfere with imaging. The method was then tested in-vivo by comparing echocardiographic stroke volume with stroke volume determined by the acetylene rebreathing technique. Normal subjects were studied with either lower body negative pressure or continuous isoproterenol infusion. The regression line was Echo SV=-19.7 + 1.2*Acet SV, with R=0.80, SEE=17.1, MPE=17%. We conclude that this is an accurate, non-geometric method for ventricular volume calculation.