Final answer:
In patients with Marfan's syndrome, the echocardiogram commonly reveals mitral valve prolapse and aortic dilatation. These are characteristic cardiovascular manifestations of Marfan's syndrome, which is a genetic disorder affecting connective tissue.
Step-by-step explanation:
The cardiac abnormalities that are frequently noted on the echo of patients with Marfan's syndrome are mitral valve prolapse and aortic dilatation. Marfan's syndrome is a genetic disorder that affects the body's connective tissue, and these two abnormalities are characteristic of the cardiovascular manifestations of the syndrome. Mitral valve prolapse can lead to mitral regurgitation, which is when the mitral valve does not close tightly, allowing blood to flow backward into the left atrium. Aortic dilatation, or enlargement of the aorta, can increase the risk of aortic dissection or rupture, both of which are life-threatening conditions.
It is worth noting that heart sounds heard via auscultation with a stethoscope include the closing of the atrioventricular valves ("lub") and semilunar valves ("dub"), which can be affected by these cardiac abnormalities. Furthermore, while stenosis and other valve disorders such as regurgitations and insufficiencies can also affect the heart, in Marfan's syndrome, mitral valve prolapse and aortic dilatation are more commonly diagnosed through echocardiography.