Cardiovascular Diseases Poster Session
Analysis of congenital heart anomalies. 1990-1997
Congenital malformations of the heart are the most common of all birth defects. A congenital heart defect occurs when the heart or blood vessels near the heart don't develop normally before birth. (1,2) Heart defects begin in the early part of pregnancy when the heart is forming. Congenital heart defects can affect any of the different parts or functions of the heart.
Congenital heart disease affects about 4-8 per 1000 live births and is a leading cause of infant mortality. One out of every 125-150 are born with heart defects each year in the United States. (2) Still probably the most common cause for early cardiac death (first week of life) Age at Presentation Immediately at birth or during the first weeks of life Clinical.
The hearts congenital defects could take place in any side of the heart: atrial, ventricular and vascular.
The common defects are classified according to:
a.- Side of the affected heart.
Some babies and children with heart defects experience no symptoms. The heart defect may be diagnosed if there is an abnormal sound referred to as a murmur. This can cause congestive heart failure. An affected child may experience a rapid heartbeat and breathing difficulties, especially during exercise (or in infants, during feeding, resulting in inadequate weight gain). Swelling of the legs or abdomen or around the eyes also may occur. (1,2,3,4)
Some heart defects result in a pale grayish or bluish coloring of the skin (called cyanosis), usually appearing soon after birth or during infancy. Examples of cyanotic defects are tetralogy of Fallot, transposition of the great arteries, tricuspid atresia, pulmonary atresia, truncus arteriosus and total anomalous pulmonary venous connection.And Acyanotic defects are atrial septum defects, ventricular septum defects, coarctation of aorta, atrioventricular canal, situs inversus.
The fact is that we don't know what causes most congenital heart defects. Among the few environmental factors known to contribute to congenital heart defects are a virus and certain drugs. Rubella (German measles), Accutane, lithium, and possibly certain anti-seizure medications. Drinking alcohol in pregnancy (babies with fetal alcohol syndrome) (FAS) cocaine, diabetes,and Down syndrome have heart defects. (5,6,7,)
Syndromes associated with congenital heart disease (8)
Trisomy 18.- there is a " Clenched fist" in wich de index finger overlaps the third finger and the fifth finger overlaps the fourth syndactyly, hypoplastic nails, ulnar or radial deviation and simian creases also occur, some patients have radial deficiencies, even phocomelia. They have manifest severe growth and mental retardation and limited survival. Congenital heart diseases are exceedingly common as many 80-100 %. VSD to be the most prevalent lesion.
Down´s syndrome.- (trisomy 21) anomalies of upper limb include simian creases, hypoplasia and clinodactyly of the fifth finger, hyperextensible joints and brachydactyly. Common somatic anomalies are hypotonia, mental deficiency, flat facies, inner epicanthal folds with upslanting palpibral fissure. Brushfield spots and open mouth with protruding tongue. The incidence of CHD is 40 %. Complete common atrioventricular canal 40 %, VSD, ostium secundum and tetralogy of Fallot.
Thrombocytopenia- absent radius syndrome.- there is bilateral radial aplasia, hypoplastic carpals, phalanges, abnormal humeri and phacomelia. 30 % CHD: ASD ostium secundum or tetralogy of Fallot. The sensitivity of prenatal diagnosis by ultrasonographic examination was much lower for isolated malformations (fetuses with only one anomaly) than for multiple malformed children, 15.3 and 48.3 per cent respectively.(9)
Rarely defects occur in which only one ventricle (single ventricle) is present, or both the pulmonary artery and aorta arise from the same ventricle (double outlet ventricle). A third rare defect occurs when the right or left side of the heart is incompletely formed - hypoplastic heart.
Obstruction defects An obstruction is a narrowing that partly or completely blocks the flow of blood. Obstructions called stenoses can occur in heart valves, arteries or veins.
The three most common forms of obstructed blood flow are pulmonary stenosis, aortic stenosis and coarctation of the aorta. Pulmonary stenosis (PS) - A defective pulmonary valve that does not open properly is called stenotic. Aortic stenosis (AS) - The aortic valve, between the left ventricle and the aorta , is narrowed.
Coarctation of the aorta . The aorta is pinched or constricted.
Ventricular septal defect (VSD) are the most common of all congenital cardiac defects. They account for about 25% of all congenital heart disease. An opening exists between the two lower chambers of the heart.
Atrioventricular Canal (AC) The primitive atrioventricular canal is closed by the formation of the ventricular and primum portion of the septa. A large hole in the center of the heart exists where the wall between the upper chambers joins the wall between the lower chambers.
Tetralogy of Fallot has four components. (TF) The two major ones are: 1) a large hole, or ventricular septal defect, that allows blood to pass from the right ventricle to the left ventricle without going through the lungs, and 2) a narrowing (stenosis) at or just beneath the pulmonary valve. This narrowing partially blocks the flow of blood from the right side of the heart to the lungs. The other two components are: 3) the right ventricle is more muscular than normal, and 4) the aorta lies directly over the ventricular septal defect. The baby becomes blue and sickly. Transposition of the great arteries (TGA) The positions of the pulmonary artery and the aorta are reversed. Here, the two major arteries leaving the heart are transposed. They each arise from the wrong pumping chamber.
Hypoplastic left heart syndrome.(HLHS) The main feature is a diminutive left ventricle. Other commonly associated abnormalities include a small left atrium, small or atretic mitral valve, decreased size of the ascending aorta and a small aortic valve. The left side of the heart - including the aorta , aortic valve, left ventricle and mitral valve - is underdeveloped. Heart valve abnormalities Some babies are born with heart valves that are narrowed, closed or blocked.
Pulmonary atresia (PA) No pulmonary valve exists, so blood can't flow from the right ventricle into the pulmonary artery and on to the lungs.
Truncus arteriosus (TA) This is a complex malformation where only one artery arises from the heart and forms the aorta and pulmonary artery.
Total Anomalous Pulmonary Venous Return (TAPVR) The pulmonary veins drain through abnormal connections to the right atrium.
Patent ductus arteriosus (PDA) While a fetus is in the womb, much of its blood goes through a passageway (ductus arteriosus) from one blood vessel to another instead of to the lungs, because the lungs are not yet in use. The passageway should close soon after birth, so the blood can take the normal route from heart to lungs and back. This problem occurs most frequently in premature babies.
Dextrocardia with Situs Inversus (SI) Distribution inversus of heart and lungs.
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|Pizarro, A; Díaz, R; (1998). Analysis of Congenital Heart Anomalies. 1990-1997. Presented at INABIS '98 - 5th Internet World Congress on Biomedical Sciences at McMaster University, Canada, Dec 7-16th. Available at URL http://www.mcmaster.ca/inabis98/cvdisease/pizarro0122/index.html|
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