Obstructive Congenital Heart Defects

Study Notes

Obstructive disorders in the context of congenital heart defects involve a blockage or narrowing that impedes blood flow.
These disorders can affect various parts of the heart and great vessels.

Coarctation of the aorta is a narrowing of the aorta, typically near the ductus arteriosus.
This narrowing obstructs blood flow to the lower part of the body.
Blood pressure is typically higher in the upper extremities and lower in the lower extremities.
There are variations in severity; some cases may be mild and go undetected until adulthood.
Severe coarctation can cause significant hemodynamic compromise in infancy.
Management includes surgical repair or balloon angioplasty to open the narrowed segment.

Aortic stenosis is a narrowing of the aortic valve, which obstructs blood flow from the left ventricle to the aorta.
The severity of aortic stenosis can range from mild to critical.
Critical aortic stenosis in newborns can cause heart failure.
Symptoms include fatigue, chest pain, and shortness of breath.
Treatment options include balloon valvuloplasty to open the valve or surgical valve replacement.

Pulmonary stenosis is a narrowing of the pulmonary valve, which obstructs blood flow from the right ventricle to the pulmonary artery.
Similar to aortic stenosis, the severity can vary.
Mild pulmonary stenosis may not require intervention.
Severe pulmonary stenosis can cause right ventricular hypertrophy and heart failure.
Treatment includes balloon valvuloplasty or surgical valvotomy to open the valve.

Pulmonary atresia is a complete obstruction of the pulmonary valve, preventing blood flow from the right ventricle to the pulmonary artery.
It is a severe congenital heart defect requiring intervention for survival.
Often associated with a ventricular septal defect (VSD).
Blood flow to the lungs depends on a patent ductus arteriosus (PDA).
Prostaglandin E1 is administered to maintain PDA patency until definitive repair.
Surgical options include creating an outflow tract from the right ventricle to the pulmonary artery or a Fontan procedure.

Tetralogy of Fallot is a combination of four heart defects: ventricular septal defect (VSD), pulmonary stenosis, overriding aorta, and right ventricular hypertrophy. When combined with pulmonary atresia, it represents a severe form of TOF because there is no pulmonary outflow.
Blood reaches the lungs through collateral arteries.
Management involves multiple surgical procedures.
Initial management focuses on maintaining adequate oxygenation and blood flow to the lungs.
Complete repair involves closing the VSD and establishing pulmonary blood flow.