dbanta,

Thanks for your question. 

Aortic stenosis is a narrowing of the aortic valve.  Located in the left ventricle, this valve prevents blood from flowing back into the heart when it contracts.  Narrowing of this valve obstructs and impedes the heart's ability to pump blood out of the heart.  As the obstruction increases, patients can develop symptoms, most commonly congestive heart failure which is cause by the pressure backing up into the lungs, squeezing fluid out and resulting in shortness of breath.  Another symptom is syncope, or loss of consciousness, which is caused by the heart's inability to meet the demand of exercise, and the lack of blood leads to passing out. 

The prevalence of aortic stenois is 2% in people over the age of 65, 3% over age 75, and 4% over the age of 85.  As the population is getting older, the prevalence of this disease is increasing.  The range of stenosis can be mild to severe, or critical.

When a doctor listens to the heart, he is checking for many different things: the rhythm; the rate; the opening and closing sounds; extra sounds which we call gallops, clicks, and rubs; and finally murmurs.  When we hear a murmur, we take special note of the timing in relation to the heart beat; intensity, location, character, and transmission of the murmur to different locations, such as the neck.  We often check the murmur in different positions, and note how the murmur changes with different breathing maneuvers.  Aortic stenosis has certain characteristics that lead a physician to suspect this diagnosis.  An electrocardiogram will add more information to the heart's status, and a special sound wave test, an echocardiogram, will help visualize the valve, left ventricle, pumping ability of the heart, and even measure the cross sectional area of the valve as well as estimating pressures on either side of the structure. 

Some people have stenosis for years without progression, while others have progressive obstruction leading to congestive heart failure and eventually surgery.  As this is usually an elderly population of patients, the decision to recommend surgery can be difficult. 

Medication can help the heart in many ways such as minimizing congestive failure, and also assisting the heart in its pumping action.  When medications cannot control the problem, surgery is hen considered.  The echocardiogram findings and the patient's condition all go into this decision.  Mortality of surgery ranges from 1 to 5%. 

As far as mortality of patients with the diagnosis, it's difficult to say.  It is important to add that follow up monitoring by the doctor, serial echocardiograms, and proper timing of surgical intervention, reduce the death rate significantly. 

I hope this has been helpful.

Martin Cane, M.D.