Aortic dilatation in bicuspid aortic valve disease.

Bicuspid aortic valve (BAV) is the most common congenital cardiac abnormality, occurring in 0.5%-1.4% of the population; this anomaly is sporadically transmitted genetically by an autosomaldominant pathway, with a 3:1 male predominance. BAV is clinically important, not only because of valve-related complications (valve dysfunction, infective endocarditis), but also because of its association with many vascular abnormalities, including aortic dilatation (Fig. 1A). The reported prevalence of BAV-related aortic dilatation ranges from 33%-80%. This variation is based on thresholds used to define dilatation, normal values for age and body surface area, and region of the aorta. Different types of aortic aneurysms have been described depending on the region involved, being the dilatation of the mid ascending tract (dilatation at the tubular ascending portion alone) the most frequent pattern observed. Age and BAV morphology have also been associated with ascending aorta (AscAo) dimension, although the role of morphology is not clearly defined.