What is the most common cause of aortic root dilation in the United States?

Aortic root dilation is commonly associated with various conditions, and Marfan's syndrome is the most prevalent cause in the United States. Marfan's syndrome is a genetic connective tissue disorder that leads to abnormal structural integrity of the aorta, which can result in dilation of the aortic root over time. The disorder is characterized by a range of cardiovascular complications, including aneurysms and regurgitation, especially involving the aortic valve and root.

Individuals with Marfan's syndrome have a defect in the fibrillin-1 protein, which contributes to the tensile strength and elasticity of connective tissues. This can make the aortic wall more susceptible to dilation and subsequent aneurysm formation due to changes in biomechanical properties.

While other conditions, such as atherosclerosis, syphilis, and trauma, can also contribute to aortic dilation, they are less common causes in the general population. Atherosclerosis primarily impacts older adults and is associated with coronary artery disease, while syphilis-related aortic dilation is relatively rare today. Trauma may result in acute injuries to the aorta but does not account for chronic conditions like aortic root dilation as seen in Marfan's syndrome. Thus, when considering the demographics and prevalence, Marfan's syndrome emerges as