Imaging and color flow Doppler echocardiography are an integral part of any 
evaluation of a patient with the Marfan syndrome. The major cardiovascular 
manifestations of this condition are aortic dilation, which may involve the 
proximal and distal aorta, aortic regurgitation, aortic dissection, mitral valve 
prolapse, and mitral regurgitation. Patients who have the Marfan syndrome should 
have serial echocardiograms to measure aortic root diameter carefully at the 
sinuses of Valsalva and subsequent levels (sinotubular junction, arch, 
descending and abdominal aorta). Additionally, color Doppler echocardiography 
assists in the diagnosis of aortic dissection and facilitates evaluation of the 
severity of aortic and mitral regurgitation that commonly complicate the Marfan 
syndrome. The risk of aortic dissection, which is the most serious manifestation 
of the Marfan syndrome, increases as the aorta enlarges. Therefore, elective 
composite graft surgery is recommended when the aortic root size reaches 60 mm, 
regardless of symptom status, or 55 mm in the presence of severe aortic 
regurgitation. Surgical replacement of the aortic root with a composite graft 
does not end the disease process. Color flow Doppler is useful in the diagnosis 
of dehiscence of the conduit sewing ring, coronary artery aneurysm, distal 
aortic dissections, and prosthetic valve dysfunction.