The main cardiovascular lesion caused by syphilis is an aortitis that causes aortic aneurysms, aortic regurgitation, and coronary ostial lesions. Spirochetal infection was once a common cause of aneurysm of the ascending thoracic aorta. These aneurysms cause complications including compression of the recurrent laryngeal nerve which results in hoarseness and pressure on the bronchi causes a brassy cough.
A characteristic radiologic finding is linear calcifica¬tion of the ascending aorta. Syphilitic aneurysms are now a rare finding in the western world as a result of aggres¬sive antibiotic treatment of syphilis in its early stages. The latent period from the initial syphilitic infection to significant aortic aneurysm formation is about 10–30 years. The aortic valve ring is typically severely dilated resulting in severe aortic regurgitation.
Microscopically, the vasa vasorum of the aorta are involved in an endarteritis obliterans that causes weakening of the arterial wall and aneurysm formation. Rupture of aneurysms may rarely occur.