Aortic valve replacement is necessary when the aortic valve has become diseased. The aortic valve can suffer from insufficiency (inability to perform adequately) or stenosis. An insufficient valve is leaky and allows blood flow retrograde from the aorta to the left ventricle during diastole. A stenotic valve prevents the flow of blood antegrade from the left ventricle to the aorta, during systole.
Either situation can result in heart failure and an enlarged left ventricle. With aortic stenosis (narrowing), angina pectoris, fainting, and congestive heart failure will develop with the severity of the narrowing. There is an increased rate of sudden death of patients with aortic stenosis. Dyspnea (labored breathing), fatigue, and palpitations are late symptoms of aortic insufficiency. Angina pectoris is associated with the latest stages of aortic insufficiency.
Congenital birth defects involving a bicuspid aortic valve can develop stenosis. These patients may become symptomatic in mid-teen years through age 65. Patients with a history rheumatic fever have a disposition for aortic stenosis, but may live symptom free for more then four decades. Calcification of the aortic valve tends to effect an older population with 30% of patients over age 85 having stenosis at autopsy.
Patients with aortic stenosis who have angina, dyspnea, or fainting are candidates for aortic valve replacement. Asymptomatic patients undergoing coronary artery bypass grafting should be treated with aortic valve replacement, but otherwise are not candidates for preventive aortic valve replacement.
Patients with a history of rheumatic fever or syphilitic aortitis (inflammation of the aorta) face the possibility of developing aortic insufficiency. Successful treatment has decreased this causative relationship. Primary causes of aortic disease commonly include bacterial endocarditis, trauma, aortic dissection, and congenital diseases.
Patients showing acute symptoms, including pulmonary edema, heart rhythm problems, or circulatory collapse, are candidates for aortic valve replacement. Chronic pathologies are recommended for surgery when patients appear symptomatic, demonstrating angina and dyspnea. Asymptomatic patients must be monitored for heart dysfunction. Left ventricular dimensions greater then 2 in (50 mm) at diastole or 3 in (70 mm) at systole are indications for replacement when aortic insufficiency is diagnosed.
Allison Joan Spiwak MSBME, The Gale Group Inc., Gale, Detroit,