ACYANOTIC HEART DISEASE

ACYANOTIC HEART DISEASE

Definition

• Congenital heart diseases are the cardiac anomalies or defects arising as a result of Structural or Functional defects of the heart or great vessels and which are present at the birth
• It may not have symptoms immediately at birth
• These lesions either obstruct the blood flow in the heart or vessels near it or alter the pathway of circulating blood

Fetal circulation

Before birth

• Oxygenated blood to fetus = by umbilical vein, dependent on mother (Placenta)    
• Fetal lungs = Collapsed, no blood flows through them and hence they are not used by the fetus
• Right heart = dominant system with pulmonary vasculature having high resistance to flow

After birth

Ductus arteriosus

•  Connects aorta with pulmonary artery
•  Carried oxygenated blood from the pulmonary artery to the aorta before birth
• Patency is maintained by low oxygen tension and PGE
• After birth, it is not needed and closes within 1 to 2 days
• -        Failure of its closure causes patent ductus arteriosus

Foramen ovale

• Connects right and left atrium
• Allows blood to pass from the right to left atrium in the fetus
• Patency is because of increased pressures in the right-sided system than in left side
• After birth, because the pressures in the left side increase, the foramen closes

Ductus venosus

• Connects umbilical vein directly to the inferior vena cava
• Thus, oxygenated blood from the placenta bypasses the liver
• Is usually patent at the time of birth
• After birth, closure occurs usually within the first week

Others

• Umbilical vein closes after birth, usually within the first week
• -Closure of umbilical veins occurs after the closure of umbilical arteries
• Umbilical arteries (2) carry deoxygenated blood from the fetus to the placenta
• Closes after the birth

CLASSIFICATION

CYANOTIC VS ACYANOTIC

CONGENITAL CYANOSIS

CENTRAL VS PERIPHERAL CYANOSIS

TAKE HOME

-        Structural or functional defects of the heart at birth = CHD

-        These are of 2 types mainly

-        Acyanotic vs cyanotic

-        Cyanosis is also of 2 types central & peripheral