Atrial Septal Defect
I. Clinical Study
GLOSSARY
embolization encrusted material, particularly small clots or bacterial vegetation on the heart valves, heart chambers, or veins which may dislodge and fly off into the circulation; they are swiftly carried to other organs, for example, pulmonary embolism.
murmur a blowing sound heard with a stethoscope usually caused by obstruction of heart valves or leaking valves.
which leads to further investigations. Because oxygenated blood is pumped from the left atrium into the right side of the heart, the organs of the body including the skin receive oxygenated blood. Thus, the individual does not become blue in the face, a condition described as cyanosis. Because of this, atrial septal defect is a cause of noncyanotic congenital heart disease.
The ECG usually shows evidence of an incomplete right bundle branch block. This is a clue for the treating physician. A transesophageal echocardiogram (TEE) is usually diagnostic. Closure of the hole in the heart is curative and should be done if symptoms are present.
ATRIAL SEPTAL DEFECT, A HOLE IN THE SEPTUM dividing the right and left atrium, is the most common congenital heart defect observed after age 12 and in adults, because the lesion is usually so small that it causes little disturbance in infants. Atrial septal defect accounts for approximately 10% of all congenital cardiac defects. With this defect oxygenated blood is shunted from the left atrium into the right atrium and traverses the pulmonary arteries and lungs and returns to the left side of the heart (Fig. 1). This circulatory disturbance is called a left to right shunt. The shunt is usually small but if the hole is large enough the right ventricle works harder to pump the extra blood delivered to it, from the left side, into the pulmonary arteries and through the pulmonary circulation back to the left side of the heart. The right ventricle over time is subjected to more strenuous work than normal. The muscle of the right ventricle becomes weaker and fails to expel sufficient blood from the chamber, and a condition referred to as right heart failure occurs. The atrial septal defect most often involves the fossa ovalis in the mid septal region; this is called an ostium secundum type of defect.
Страницы: 1 | 2
- I. CLINICAL STUDY
Study question: A study by Attie et al. assessed weather surgical treatment of atrial septal defects in patients over age 40 improves their long-term outcome. - BIBLIOGRAPHY
Attie, F., Rosas, M., Granados, N. et al. Surgical treatment for secundum atrial septal defects in patients greater than 40 years old. J. Am. Coll. Cardiol., 58: 2035–4, 2001.