Abstract 16522: Improved Screening for Aortic Root Dilation by Transthoracic Echocardiography
Intro: Aortic root dilation is a potent risk factor for aortic complications such as dissection or rupture, which are often catastrophic. Transthoracic echo (TTE) reliably assesses aortic root size, which is currently best correlated with body surface area (BSA), but is a weak correlation in patients over 40 years old (r=0.4). Scaling to internal cardiac structures, specifically the left ventricular outflow tract (LVOT), has not yet been explored, and can improve on existing practice. Accurately detecting aortic dilation can help optimize surgical intervention and minimize complications. Hypothesis: The LVOT size correlates with aortic root size and can thus be used for screening of aortic root dilation.
Methods: Images from the Stanford echo database were reviewed and measures of the aortic root, at the level of the sinuses of Valsalva, and the LVOT, were performed on parasternal long axis view. The study population consisted of 76 normal controls and 74 patients with known cardiovascular disease selected at random. Patients with poor image quality, history of aortic root/valve repair or replacement, malformed aortic valves, cardiac transplant, and more than mild aortic regurgitation were excluded.
Results: Of the 150 patients, there were 79 women and 71 men, with a mean age of 49 ± 18 years, height 169 ± 10 cm, and weight 74 ± 23 kg. The mean aortic root diameter was 3.26 ± 0.31 cm and LVOT 2.15 ± 0.24 cm. Overall, there was very good correlation between aortic root and LVOT diameters with r = 0.82 (p < .0001), see Figure 1. For men, r = 0.69, and for women, r = 0.74. For the normals, r = 0.77, and r = 0.9 for the abnormals. The correlation of aortic root diameter was 0.58 with BSA, 0.32 with body mass index, 0.55 with height, and 0.49 with weight (p < .0001 for all). Fig 1: Bivariate fit model, 95% confidence limits
Conclusions: LVOT size on TTE is an easy and excellent parameter for screening of aortic root dilation in adults and is more accurate than the current practice of utilizing body surface area.
- © 2010 by American Heart Association, Inc.