心血管系统疾病先天性心脏病（英文） .ppt

Congenital Heart DiseaseEpidemiology of CHDPrevalenceCHD occurs in 0.5-0.8%of live births;The incidence is higher among stillborns死产(3-4%),abortuses流产(10-25%),and premature infants(about 2%excluding PDA);About 2-3 in 1,000 newborn infants will be symptomatic with heart disease in the first year of life.Epidemiology of CHDPrevalenceThe diagnosis is established by 1 week of age in 40-50%of patients with CHD and by 1 month of age in 50-60%patients;With the advances in both palliative姑息and corrective surgery of the last 20 years,the number of children with CHD surviving to adulthood has increased dramatically;Epidemiology of CHDPrevalenceDespite these advances,CHD remains the leading cause of death in children with congenital malformations;Most congenital defects are well tolerated in the fetus because of the parallel nature of the fetal circulation.Epidemiology of CHDEtiologyThe cause of most CHD is unknown.Genetic factors play some role in CHD.About eight percent of cases result mainly from genetic factors.The heart defect is usually part of a chromosomal disorder such as Downs syndrome.However,no specific gene locus for CHD has been identified.Epidemiology of CHDEtiologyA child born to a parent with CHD has a substantially大体上increased likelihood of having a similar congenital lesion.The risk may be as high as 15 percent.For certain lesions,there appears to be a greater risk of transmission from the mother than from the father.Epidemiology of CHDEtiologyAbout two percent of cases of CHD are primarily the result of environmental or external factors.Such factors include rubella风疹infection and ingestion of certain drugs,such as lithium锂.CHD is a prominent component of the fetal alcohol syndrome.The etiologic role of other agents,such as anticonvulsant medications and exogenous外源female sex hormones,is uncertain.Noninvasive Diagnostic Studies Chest X ray The location of the heartThe size of the heart The relationship between heart and great vesselThe blood flow of the lungNoninvasive Diagnostic Studies Echocardiography Echocardiography has great value in assessing congenital cardiac anomalies and should usually be the first advanced diagnostic study to be carried out if the history,the physical examination,the chest X ray,and the electrocardiogram suggest the presence of congenital heart disease.Noninvasive Diagnostic Studies Echocardiography The standard M-mode display and the two-dimensional display provide such information about cardiac anatomy as the size of the cardiac chambers,the connections of the great vessels,abnormalities of the valves,and subvalvular obstructions.Noninvasive Diagnostic Studies Doppler ultrasonography Doppler ultrasonography is useful in detecting septal defects and directly assessing the amount of blood that shunts through the defect.The size of the shunt through a septal defect can also be estimated from Doppler ultrasound studies by comparing the velocity of the blood flow through the aorta with velocity through the pulmonary artery.Noninvasive Diagnostic Studies Transesophageal echocardiography Transesophageal echocardiography is particularly valuable for assessing atrial septal defects,but it also visualizes other lesions effectively.Doppler studies are useful in assessing valvular stenosis and regurgitation as well.Noninvasive Diagnostic Studies Computed tomography(CT)CT provides a good display of the anatomic abnormalities associated with congenital heart disease and offers advantages over echocardiography in demonstrating anomalies involving the great vessels.Computed tomographyNoninvasive Diagnostic Studies Magnetic resonance imaging(MRI)MRI provides information similar to that provided by CT.MRI offers better resolution than CT without the disadvantages of the radiopaque不透射线的contrast medium used in that technique.Noninvasive Diagnostic Studies Cardiac catheterization and selective angiocardiography are the most definitive diagnostic techniques currently available for use in congenital heart disease.However,noninvasive studies often provide information that is equivalent to that obtained from cardiac catheterization and is sufficient for planning surgical treatment.Congenital Cardiac Anomalies in Children Ventricular Septal Defect(VSD)VSD is the most common congenital cardiac anomaly in infants.It is rarely seen in adults because substantial VSD that are not corrected surgically are associated with a high mortality.In addition,the incidence of spontaneous closure of VSD is relatively high;closure occurs particularly often in infancy but also in later years.Congenital Cardiac Anomalies in Children Ventricular Septal Defect The VSD that do appear in adults as isolated anomalies are usually less than 1 cm in diameter.Because the opening is quite small,normal systolic pressure can be maintained in the right ventricle and in the pulmonary artery.Congenital Cardiac Anomalies in Children Ventricular Septal Defect In infants with a large VSD,medical management has two aims:to control h