Incremental value of right parasternal transthoracic echocardiographic examination over the left parasternal approach in assessing ascending aorta size: Additional benefit of three-dimensional echocardiography.

Background: The ascending aorta (AA) has not been well studied using two-dimensional right parasternal transthoracic echocardiographic examination (2DRPE).

Aim: The aim of the present study was to assess the incremental value of 2DRPE over two-dimensional left parasternal transthoracic echocardiographic examination (2DLPE) in evaluating the size of AA in adult patients (pts) and, secondly, to determine whether live/real time three-dimensional (3D) RPE provided any additional benefit over 2DRPE.

Materials And Methods: The AA was successfully imaged by 2DLPE, 2DRPE, and 3D RPE in 87 of 141 (61.7%) pts which comprised of two groups of consecutive pts separated by an interval of 2 weeks.

Results: The maximum length of AA visualized by 2DRPE (4.98 ± 0.89) was larger than 2DLPE in 76/87(87%) pts (P < 0.001). Both the maximum systolic AA inner luminal width and leading edge-to-leading edge width by 2DRPE were greater than 2DLPE (P < 0.001). Similar to other noninvasive imaging modalities where mid-AA width is taken at level of right pulmonary artery, mid-AA width could also be taken at this level by 2DRPE in 79/87(91%) pts since this landmark was visualized during 2DRPE. However, this vessel could be visualized in only 2/87 (2%) pts with 2DLPE. 3DRPE conferred additional benefit over 2DRPE. The maximal AA length by 3DRPE was larger than 2DRPE in 60/87(69%) pts, and the maximal inner lumen and leading edge to leading edge widths were larger in 54/87(62%) and 66/87(76%) pts, respectively.

Conclusion: Our preliminary study demonstrates significant incremental value of 2DRPE over 2DLPE in the assessment of AA. 3DRPE confers an additional advantage over 2DRPE.