Cardiac and respiratry conditions

Fetal circulation

Blood flows from body into R atrium

R atrium => foramen ovale

foramen ovale => L atrium and L ventricle

L heart => body while bypassing lungs

Foramen ovale

In utero connects R and L atria of heart

Closes naturally after birth due to pressure difference between L and R sides

Ductus arteriosus

A small vein in utero that connects pulmonary arteries to aorta. Allows oxygenated blood from the placenta to reach the aorta

Normally closes ~1 week after birth, but can be useful open if child has other congenital heart defects

Cyanotic conditions (‘blue babies’)

Blood is inappropriately shunted from the R to the L side of heart and deoxygenated blood enters body circulation

Acyanotic conditions (‘pink babies’)

Blood is inappropriately shunted from the L to the R side of heart and oxygenated blood is recirculated through the lungs

Less severe conditions, but put higher load on the R heart

Atrial septal defect (ASD)

Acyanotic CHD where the foramen ovale does not close (patent foramen ovale or PFO)

Blood will be pushed from the L to the R atria, leading to less efficient pumping

Relatively mild condition. May close naturally over time, but surgery indicated if open by 4-6y/o

Ventricular septal defect (VSD)

Most common CHD. Acyanotic condition

Hole present between L and R ventricles. Blood is pushed from L to R ventricle and pulmonary loop must carry larger load

May close naturally, may need surgery if infant is in respiratory distress or has difficulty with feeding

Patent ductus arteriosus (PDA)

Acyanotic CHD where PDA stays open for more than 1 week and blood is shunted from the aorta to pulmonary arteries

Treated with medication to trigger closure

May be lifesaving if other CHD present that limits flow of oxygenated blood

Pulmonary stenosis

Acyanotic condition with narrowing of pulmonary valve

Sx range from mild to severe. Leads to RV hypertrophy

Aortic stenosis

Acyanotic condition with narrowing of aortic valve

Sx range from mild to severe. Leads to LV hypertrophy

Coartaction of the aorta

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