Most Common Congenital Heart Defects in the United States
The most common congenital heart defects in the United States are ventricular septal defect (VSD), atrial septal defect (ASD), and bicuspid aortic valve, with VSD being the most prevalent at approximately 27.5 per 10,000 births. 1
Prevalence and Classification
Congenital heart disease (CHD) occurs in approximately 0.4% to 1% of live births in the United States 2. The overall prevalence is estimated at 81.4 per 10,000 births, with specific defects occurring at the following rates:
- Most common defects (in order of frequency):
- Muscular ventricular septal defect: 27.5 per 10,000 births
- Perimembranous ventricular septal defect: 10.6 per 10,000 births
- Secundum atrial septal defect: 10.3 per 10,000 births
- Bicuspid aortic valve (common in adults)
- Tetralogy of Fallot: 4.7 per 10,000 births (most common cyanotic CHD)
- Transposition of the great arteries: 2.3 per 10,000 births
Classification by Complexity
The American College of Cardiology/American Heart Association classifies congenital heart defects according to anatomical complexity 2:
Simple CHD (Class I)
- Isolated small atrial septal defect (ASD)
- Isolated small ventricular septal defect (VSD)
- Mild isolated pulmonic stenosis
- Previously repaired conditions without significant residual effects:
- Ligated/occluded patent ductus arteriosus
- Repaired secundum ASD or sinus venosus defect
- Repaired VSD
Moderate Complexity CHD (Class II)
- Aorto-left ventricular fistula
- Anomalous pulmonary venous connection
- Atrioventricular septal defect (AVSD)
- Coarctation of the aorta
- Ebstein anomaly
- Moderate/large unrepaired secundum ASD
- Patent ductus arteriosus (moderate/large)
- Pulmonary valve stenosis (moderate or greater)
- Repaired tetralogy of Fallot
- Sinus venosus defect
Great Complexity CHD (Class III)
- Cyanotic congenital heart defects
- Double-outlet ventricle
- Fontan procedure
- Single ventricle conditions
- Pulmonary atresia
- Transposition of the great arteries
- Truncus arteriosus
Adult Diagnosis of CHD
Interestingly, about 26.5% of CHD cases are only diagnosed in adulthood 3. Among adults newly diagnosed with CHD:
- Pre-tricuspid shunts (particularly ASD) account for 48.1% of cases
- Bicuspid aortic valve represents 16.8% of cases
- Aortic coarctation accounts for 8.2% of cases
Clinical Significance and Outcomes
The mortality and morbidity associated with congenital heart defects vary significantly based on complexity:
- Simple defects often have excellent long-term outcomes with appropriate management
- Moderate complexity defects may require intervention but generally have good outcomes
- Complex defects often require multiple interventions and have higher morbidity
For tetralogy of Fallot, the most common complex defect with the longest surgical history, long-term survival after complete repair is 86% at 32 years 2. However, the risk of sudden cardiac death increases over time, reaching approximately 6-9% by 30 years after surgery.
Risk Factors and Genetic Considerations
Congenital heart defects often have genetic components:
- Chromosomal abnormalities are detected in approximately 33% of fetal cases with CHD 4
- Risk increases if a parent or sibling has a congenital heart defect
- Maternal factors such as viral infections (particularly Rubella) in the first trimester, excessive alcohol consumption during pregnancy, and certain medications can increase risk 5
Understanding the most common congenital heart defects helps guide screening, early intervention, and long-term management strategies to improve outcomes for affected individuals.