Superiority of 3-dimensional versus 2-dimensional echocardiography for left ventricular volume assessment in small piglet hearts

To evaluate the accuracy of 3-dimensional (3D) echocardiography in the estimation of left ventricular (LV) volume in vivo, we studied 15 newborn piglets ranging in weight from 2.6 to 11.8 kg. Measurements of beating LV volumes by 3D echocardiograms were compared with measurements by conductance catheter and transthoracic 2-dimensional (2D) echocardiograms with the use of Simpson's rule. The results of both 3D and 2D echocardiograms correlated strongly with the actual volume (r = 0.98 and 0.95 for LV end-diastolic volume, and 0.998 and 0.95 for LV end-systolic volume, respectively). However, the standard error of estimate (SEE) for 2D echocardiography was larger than for 3D. The SEE values for LV end-diastolic volume for 2D and 3D echocardiograms were 2.30 mt and 1.85 mt, respectively, and 1.52 mt and 0.5 mL for LV end-systolic volume. We conclude that 3D echocardiography not only accurately measures LV volume and systolic function in a newborn heart, it is more precise than measurements from 2D echocardiography in the assessment of small beating hearts.