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Aortic Stenosis
The aortic heart valve allows for the unidirectional ejection of oxygenated blood from inside the heart (left ventricle) to enter the systemic circulation. It is composed of two leaflets of tissue (bicuspid valve) which open and close systematically with the contraction and relaxation of the heart. Adequate functioning of the aortic valve is dependent on its complete opening, which allows the unobstructed passage of blood, and tight closure (after ejection of blood) which prevents back flow into the heart. The progressive narrowing of the aortic valve is referred to as aortic stenosis (AS).
Causes of Aortic Stenosis (AS)
1. Rheumatic Heart Disease (secondary to rheumatic fever)
2. Congenital cause (bicuspid valve): found in up to 2% of the general population.
3. Idiopathic sclerosis (scarring of the aortic valve in the elderly that occurs for unknown reasons).
The principal problem with aortic stenosis is obstruction to blood flow. This usually does not occur to a significant degree in cases of AS due to idiopathic sclerosis. Those with rheumatic heart disease, or bicuspid valve, can develop symptoms of AS (most commonly) between the age of 40 and 60. With an increase of obstruction to blood flow (through the stenotic valve), the heart attempts to compensate by enlarging. Eventually, the heart begins to decompensate and the patient will develop symptoms consistent with aortic stenosis. Common symptoms include: increasing shortness of breath with exertion, fainting (particularly with exertion), and chest pains. Advanced AS patients may develop congestive heart failure and cardiac arrhythmias (atrial fibrillation). Evaluation of suspected AS will include: EKG, CXR, and echocardiogram. Some patients may require cardiac catheterization prior to surgical correction of the diseased valve.
Treatment will consist primarily of artificial heart valve replacement in those who develop more significant symptoms. Salt restriction, diuretic therapy (furosemide), and digoxin are also effective. Strenuous exercise should be avoided. Once symptoms of AS develop, average life expectancy is less than 5 years if left untreated. The presence of congestive heart failure indicates advanced disease, with average survival estimated to be less than 2 years after its onset. Those with atrial fibrillation may require medications to control the rate, and blood thinning medications (warfarin) to decrease the risk of stroke. The Cardiologist is the expert in the evaluation of this problem. RECOMMENDATION: Patients with this condition should not smoke and should follow a cardiac diet low in fat and cholesterol. These patients should be cautioned against the use of any cardiac stimulants (decongestants and cold medications).Note: Patients with aortic stenosis will require antibiotic prophylaxis before dental or surgical procedures. See your doctor for assistance.
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