Bicuspid aortic valve (BAV) disease is the most common congenital cardiovascular malformation with prevalence of 1-2% in the human population (Hoffman, 1990;Hoffman & Kaplan, 2002). Current clinical and scientific studies reveal that bicuspid aortic disease is not a simple valve condition. It increasingly appears to be a genetically based connective tissue disorder. It has been reported that a molecular abnormality in the extracellular matrix may lead to abnormal cell differentiation during valvulogenesis; however, the exact mechanism remains unclear (Nataatmadja et al., 2003;Eisenberg et al., 1995;Fedak et al., 2002). An important problem is that the aorta of patients with BAV is not normal in strength or size. BAV is frequently associated with other cardiovascular malformations, including aortic root dilatation, aortic stenosis, coarctation of the aorta, and ventricular defects. Although symptoms often manifest in adulthood, there is a wide spectrum of presentations ranging from severe disease detected in utero to asymptomatic disease in old age. Complications can include aortic valve stenosis or incompetence, endocarditis, aortic aneurysm formation, and aortic dissection. Two large contemporary series have demonstrated that the life expectancy in adults with normally functioning BAV is not shortened when compared with that of the general population whereas age and severity of disease were associated with primary cardiac events (Michelena et al., 2008;Tzemos et al., 2008). The risk of aortic dilatation and aortic dissection is higher in patients with BAV than in the general population. In most of patients with BAV, symptoms and physical findings often are absent for many years, whereas the clinical consequences in patients with BAV are associated with regurgitation, endocarditis, and aortic aneurism and dissection. Endocarditis is an important complication for patients with BAV. It occurs particularly in patients with regurgitant or obstructive valves, although the risk of endocarditis may also be high also in hemodynamically stable patients. Prior studies reported significant mortality in patients with infected BAV. However, the last ACC/AHA guidelines recommend that antibiotic prophylaxis is not indicated in young patients and adolescents with BAV (Nishimura et al., 2008). Patients with moderate valvular dysfunction and normal left ventricular dimensions should be systematically monitored using echocardiography. In adition hypertension should be carefully followed by a cardiologist or cardiac surgeon with specific interest in this valve pathology. Adequate oral hygiene and antibiotic prophylaxis during dental procedures or when a poor cardiac condition is present are important for preventing endocarditis. Surgery is indicated for severe valvular dysfunction, symptomatic patients, and aortic dilatation.
www.intechopen.comAortic Valve 276This article addresses the embryology, genetic, pathophysiology, clinical presentation, diagnostic procedures, and therapeutic strategies for BAV. In this chapter we will prese...