Aortic Valve Diseases
AORTIC VALVE DISEASES
The aortic valve is located at the left ventricular outlet of the heart. It controls the flow of blood from the heart to the aorta which is the largest artery.
Aortic stenosis occurs most commonly as a result of acute rheumatic fever. Congenital or degenerative causes may also cause aortic stenosis.
The most common congenital cause is a bicuspid aortic valve, although it is supposed to be tricuspid. The valve attempts to overcome the obstruction in front of it by increasing the muscle mass (hypertrophy) of the left ventricle, which pumps blood to the body. Over time, the compensatory mechanism becomes inadequate and heart failure results. Patients usually live a long time without symptoms. The valve area is usually 2.5-3.5 cm2, and symptoms occur when this area falls below 1cm2.
The classic symptoms of aortic stenosis are:
congestive heart failure (dyspnea, fatigue, peripheral edema), chest pain, and syncope (fainting). After the appearance of these symptoms, the course of the disease worsens. Although an echocardiogram is sufficient for diagnosis, cardiac catheterization should be performed for preoperative assessment.
In an echocardiogram,
A valve area of less than 0.7 cm in asymptomatic patients or in patients with congestive heart failure, angina (chest pain), and syncope is sufficient to indicate surgery. If the average systolic pressure difference between the left ventricle and the aorta exceeds 50 mmHg, this is an indication for surgery.
Aortic Valve Regurgitation
The most common cause of aortic valve regurgitation is acute injury from rheumatic fever. In addition, disease and trauma to the connective tissue holding the valve can also cause valve regurgitation. In aortic valve regurgitation, some of the blood pumped into the aorta flows back into the left ventricle, resulting in an increased workload on the ventricle. Just as in stenosis, this condition is tolerated for a time by hypertrophy of muscle mass. However, over time, the function of the ventricles deteriorates. It takes many years for symptoms to appear. The first symptom is dyspnea due to left ventricular dysfunction. Over time, heart failure and angina (chest pain) occur.
Asymptomatic patients with normal left ventricular function should be treated medically and followed up. In asymptomatic patients, if left ventricular function deteriorates on echocardiogram (if there is a decrease in FS and EF with a left ventricular end-systolic diameter greater than 55 mm), catheterization should be arranged, and if severe aortic regurgitation and left ventricular dysfunction are found on catheterization, the patient should undergo surgery.
Patients with severe aortic regurgitation and congestive heart failure should be operated on as soon as possible.
Surgical treatment consists of replacing the heart valve with a prosthetic valve of appropriate size and structure. In some cases, the aorta (the main artery of the heart) is enlarged, and the valve is inadequate at the same time. In this case, it may be necessary to replace the aorta together with the valve with an artificial material in the form of a tube called a graft.