The incidence of moderate and severe forms of congeni¬tal heart disease (CHD) is about 6 per 1000 live births, but it is 19 per 1000 live births if the potentially serious bicuspid aortic valve is included. If very small muscular ventricular septal defects (VSDs) are included, all forms increase to 75 per 1000 live births. Although several classifications are used, the oldest and most meaningful is the division into cyanotic and noncyanotic CHD.
Cyanotic CHD involves right-to-left shunts. The arterial circulatory system receives an overflow of deoxy-genated blood from the right side of the heart resulting in a discoloration of the tongue, lips, and mucous membranes. Organs and tissues receive blood low in oxygen. Noncyanotic CHD mainly involves left-to-right shunts and valvular defects. In individuals with left-to-right shunts oxygenated blood flows from the left side of the heart into the right atrium or ventricle and is returned to the lungs. Usually there is no significant hypoxemia, except in children with severe defects. Fortunately noncyanotic CHD is much more common than cyanotic disease. The noncyanotic group includes the following:
1. Ventricular septal defect, incidence ^30%, more than 80% close before age 2–3

Страницы: 1 | 2