COARCTATION OF THE AORTA

COARCTATION OF THE AORTA (see also [For More Information] ). This malformation is likely to produce significant symptoms either in early infancy or after age 20 to 30 years.5,17 The majority of patients who survive early life live to reach adulthood, but sporadic examples of exceptional longevity should not obscure the inherent risks that shorten life span.5 Half of unoperated patients die by age 30, and more than three-quarters by age 50.17 The oldest recorded survivor was a 92-year-old man reported by Reynaud in 1828.18

Survival and morbidity in adults with aortic coarctation are influenced by coexisting congenital and acquired cardiac and vascular diseases. The most common associated congenital malformation is the bicuspid aortic valve5 (see above). Infective endocarditis is more likely to involve the bicuspid aortic valve than the site of coarctation.5 A less common but potentially lethal coexisting malformation is a congenital aneurysm of the circle of Willis (Fig. 30–3 Fig. 30–3 ), which typically becomes manifested by sudden rupture.19 Dissection or rupture of the aorta itself is a dramatic complication with peak incidence in the third and fourth decades.5 The proximal ascending aorta is the most common site, a susceptibility influenced in part by a coexisting bicuspid aortic valve or by XO Turner’s syndrome.5 The second site of rupture or dissection is in the postcoarctation aorta, which, like the aortic root, histologically resembles cystic medial necrosis.20 Left ventricular failure in unoperated patients with coarctation of the aorta occurs either before the first year of life or after age 40 but seldom in between.5 Systemic hypertension predisposes to premature coronary artery disease.21

PULMONARY VALVE STENOSIS

PULMONARY VALVE STENOSIS (see also [For More Information] , and Fig. 29–42 Fig. 29–42 ). Represented by a pliant conical or dome-shaped valve with a narrow outlet at its apex, this malformation typically occurs as an isolated anomaly and is the most common variety of congenital obstruction to right ventricular outflow.5 Survival into adolescence and adulthood is the rule, except for pinpoint pulmonary stenosis in neonates. Longevity depends chiefly on three variables: (1) the initial severity of obstruction, (2) whether a given degree of obstruction remains constant or progresses, and (3) the functional adequacy of the pressure-overloaded right ventricle.22–24 The orifice size of isolated pulmonary valve stenosis usually increases appropriately with body growth. However, the development of secondary hypertrophic subpulmonary stenosis (Fig. 30–4 Fig. 30–4 ) or fibrocalcific thickening in older patients may augment the degree of obstruction. Although subjective complaints become more prevalent as years go by, equivalent degrees of stenosis may limit one patient in childhood yet leave another relatively unencumbered as an adult.5 Right ventricular failure is the most common cause of death. Infective endocarditis is a risk, except perhaps in mild pulmonary valve stenosis.

Date: 2014-12-21; view: 1094