Aortic stenosis (AS or AoS) is the narrowing  of the exit of the left ventricle of the heart (where the aorta begins), such that problems result. It may occur at the aortic valve as well as above and below this level. It typically gets worse over time. Symptoms often come on gradually with a decreased ability to exercise often occurring first. If heart failure, loss of consciousness, or heart related chest pain occur due to AS the outcomes are worse. Loss of consciousness typically occurs with standing or exercising. Signs of heart failure include shortness of breath especially when lying down, at night, or with exercise, and swelling of the legs. Thickening of the valve without narrowing is known as aortic sclerosis.Causes include being born with a bicuspid aortic valve, and rheumatic fever; a normal valve may also harden over the decades. A bicuspid aortic valve affects about one to two percent of the population. As of 2014 rheumatic heart disease mostly occurs in the developing world. Risk factors are similar to those of coronary artery disease and include smoking, high blood pressure, high cholesterol, diabetes, and being male. The aortic valve usually has three leaflets and is located between the left ventricle of the heart, and the aorta. AS typically results in a heart murmur. Its severity can be divided into mild, moderate, severe, and very severe, distinguishable by ultrasound scan of the heart.Aortic stenosis is typically followed using repeated ultrasound scans.
Infection with the bacteria Chlamydia pneumoniae has been demonstrated in some patients prior to the development of Cogan syndrome, leading some researchers to hypothesize that the autoimmune disease may be initiated by the infection. C. pneumoniae is a common cause of mild pneumonia, and the vast majority of patients who are infected with the bacteria do not develop Cogan syndrome. Diagnosis
While the white blood cell count, erythrocyte sedimentation rate, and C-reactive protein tests may be abnormal and there may be abnormally high levels of platelets in the blood or too few red blood cells in the blood, none of these findings is a reliable indicator of the disease. A slit-lamp examination is essential. Recent work has suggested that high-resolution MRI and antibodies to inner ear antigens may be helpful. Cogan syndrome can occur in children, and is particularly difficult
to recognize in that situation. Treatment
For more severe disease, oral corticosteroids may be necessary to reduce the inflammatory response. When large amounts of steroids are required or if the disease is severe and is not responding to steroid therapy, other immunosuppressive medications often are recommended. These immunosuppressive drugs include methotrexate, cyclophosphamide, cyclosporine or azathioprine. In some cases, combinations of these medicines are prescribed. Occasionally, if the disease has damaged blood vessels in the ear, cochlear implantation may be used to restore some sense of hearing.Cinnarizine is mainly used to treat nausea and vomiting associated with motion sickness, vertigo, Ménières disease, or Cogan syndrome. Studies have shown it to produce significant improvement in hearing loss in some patients.