TOMOGRAPHIC 3-DIMENSIONAL ECHOCARDIOGRAPHIC DETERMINATION OF CHAMBER SIZE AND SYSTOLIC FUNCTION IN PATIENTS WITH LEFT-VENTRICULAR ANEURYSM - COMPARISON TO MAGNETIC-RESONANCE-IMAGING, CINEVENTRICULOGRAPHY, AND 2-DIMENSIONAL ECHOCARDIOGRAPHY

Background Two-dimensional (2D) echocardiographic approaches based on geometric assumptions face the greatest limitations and inaccuracies i n patients with left ventricular (LV) aneurysms. Three-dimensional (3D ) echocardiographic techniques can potentially overcome these limitati ons to date, however, although tested in experimental models of aneury sms, they have not been applied to a series of patients with such dist ortion. The purpose of this study was therefore to validate the clinic al application of tomographic 3D echocardiopraphy (3DE) by the routine transthoracic approach to determine LV chamber size and systolic func tion without geometric assumptions in patients with LV aneurysms. Meth ods and Results In 23 patients with chronic stable LV aneurysms, LV en d-systolic and end-diastolic volumes (LVEDV, LVESV) and ejection fract ion (LVEF) by tomographic 3DE were compared with results from 3D magne tic resonance tomography (3DMRT) as an independent reference as well a s with the conventional techniques of single plane and biplane 2D echo cardiography and biplane cineventriculography. Dynamic 3DE image data sets were obtained from a transthoracic apical view with the use of a rotating probe with acquisition gated to control for ECG and respirati on (Echo-scan, TomTec). Volumes were calculated from the 3D data sets by summating the volumes of multiple parallel disks. 3DE results corre lated and agreed well with those by 3DMRT, with better correlation and agreement than provided by other techniques for LVEDV (3DE: r=.97, SE E=14.7 mL, SD of differences from 3DMRT=14.5 mL; other techniques: r=. 84 to .93, SEE=30.7 to 41.6 mL [P<.001 versus 3DE by F test], SD of di fferences = 31.5 to 40.7 mL [P<.001 versus 3DE by F test]). The same a lso pertained to LVESV (3DE: r=.97, SEE=12.4 mL, SD of differences=12. 9 mL; other techniques: r=.81 to .90, SEE=24.7 to 37.2 mL [P<.001], SD of differences=27.6 to 36.8 mL [P<.005]) and LVEF (3DE: r=.74, SEE=5. 6%, SD of differences=6.7%; other techniques: r=.14 to .59, SEE=9.5% t o 10.1% [P<.01], SD of differences=9.5% to 12.6% [P<.05]). Compared wi th 3DMRT, 3DE was less lime consuming and patient discomfort was less. Conclusions Tomographic 3DE is an accurate noninvasive technique for calculating LV volumes and systolic function in patients with LV aneur ysm. Unlike current 2D methods, tomographic 3DE requires no geometric assumptions that limit accuracy.