Comparison of 3-dimensional echocardiographic left ventricular volume assessment from different acoustic windows.

Three-dimensional echocardiography (3DE) has been reported to be accurate and precise in left ventricular (LV) volume assessment. We validated the accuracy of 3DE for quantifying LV volume acquired from various different acoustic windows. Twenty patients with good acoustic windows were enrolled. The 3DE images were acquired from the point of maximal intensity (PMI) (A, apical 4-chamber view), the point of 1 intercostal space above from the PMI (B), the point of medial side of PMI with angling probe laterally, toward the patients' left shoulder (C, right ventricular modified 4-chamber view) and the point of 4th intercostal space of midclavicular line (D). The measurements of LV volume at end diastole and end systole by 3DE acquired from 4 different acoustic windows were done offline and analyzed. We set the LV volume quantified from image of apical 4-chamber view as the standard LV volume. Linear association between the methods was measured with simple linear regression analysis and with Pearson correlation coefficient. Bland-Altman plot was created to calculate the limits of agreement. The end diastolic and end systolic LV volumes measured from apical 4-chamber view ranged from 45.7 to 105.5 mL and from 17 to 35.5 mL. Using simple linear regression analysis and Bland-Altman plot analysis, both the end diastolic and end systolic LV volumes measured from each image acquired from each positions showed high agreement. Using the semi-automated analysis tool of the QLAB Advanced Ultrasound Quantification Software Release 8.1, the maximal time required for the volume measurement of images from A, B, C and D were 180, 208, 248 and 359 seconds, respectively. Our results demonstrated the feasibility and accuracy of 3DE for clinical assessment of LV volume irrespective of any acoustic windows.