Congenital Heart Disease

There is no single cause of CHD, and in many cases, the exact reason remains unknown. However, several factors can increase the risk, including:

• Genetic conditions – CHD is more common in babies with genetic syndromes such as Down’s syndrome, Turner syndrome, and DiGeorge syndrome.
• Maternal infections during pregnancy – Rubella (German measles) during the first trimester can significantly increase the risk of heart defects.
• Maternal health conditions – Uncontrolled diabetes, obesity, or lupus can increase the likelihood of CHD.
• Medications and substance exposure – Certain drugs, including some anti-seizure medications, acne treatments (retinoids), and alcohol consumption during pregnancy, have been linked to CHD.

There are many different types of CHD, and some babies may have multiple defects. The severity of these conditions varies, ranging from minor issues that resolve on their own to complex defects requiring lifelong medical care.

1. Septal Defects (Holes in the Heart)

• Atrial Septal Defect (ASD) – A hole in the wall between the heart’s upper chambers (atria).
• Ventricular Septal Defect (VSD) – A hole in the wall between the heart’s lower chambers (ventricles).
• Small septal defects may close naturally, but larger defects may require surgery or catheter-based procedures.

2. Patent Ductus Arteriosus (PDA)

• A persistent fetal blood vessel (ductus arteriosus) that should close after birth remains open, affecting normal blood flow between the aorta and pulmonary artery.
• PDA is more common in premature babies and may require medication, catheter-based closure, or surgery if it does not close naturally.

3. Heart Valve Defects

• The heart valves may not develop properly, leading to narrowing (stenosis), leaking (regurgitation), or absence of a valve.
• Examples include aortic stenosis and pulmonary valve atresia.
• Treatment ranges from medications and catheter-based interventions to valve replacement surgery.

4. Coarctation of the Aorta

• A narrowing of the aorta, the main artery carrying blood from the heart to the body.
• This can cause high blood pressure and heart strain, requiring surgery or balloon angioplasty to correct.

5. Tetralogy of Fallot (TOF)

A combination of four defects that cause low oxygen levels in the blood, leading to cyanosis (bluish skin and lips). The four defects are:
1.      Ventricular septal defect (VSD)
2.      Pulmonary stenosis (narrowing of the pulmonary valve)
3.      Overriding aorta (mispositioned aorta)
4.      Right ventricular hypertrophy (thickened right ventricle)

Surgical correction, typically in infancy, is necessary for survival and improved quality of life.

6. Transposition of the Great Arteries (TGA)

• The main arteries leaving the heart are switched, meaning oxygen-poor blood circulates through the body while oxygen-rich blood remains in the lungs.
• Requires immediate surgical intervention after birth to redirect blood flow.

7. Hypoplastic Left Heart Syndrome (HLHS)

• The left side of the heart is underdeveloped, making it unable to effectively pump blood.
• Babies with HLHS require multiple surgeries or a heart transplant to survive.

Most cases of CHD are now detected before birth through routine fetal ultrasound scans. However, some mild cases may not be diagnosed until childhood or adulthood. Diagnostic tests include:

• Fetal Echocardiography – Performed during pregnancy if a heart defect is suspected.
• Newborn Pulse Oximetry Screening – Measures oxygen levels in newborns to detect critical CHD.
• Echocardiogram (Heart Ultrasound) – A key imaging tool for diagnosing CHD after birth.
• Electrocardiogram (ECG) – Records the electrical activity of the heart to check for rhythm abnormalities.
• Cardiac MRI and CT Scans – Provide detailed images of heart structures and blood flow.

Early diagnosis and treatment significantly improve survival and long-term health outcomes.

The treatment for CHD depends on the type and severity of the defect:

1. Medications

• Diuretics – Help remove excess fluid buildup.
• Beta-blockers or ACE inhibitors – Used in some CHD cases to manage heart function.
• Prostaglandins – May be given in newborns with severe CHD to keep vital blood vessels open until surgery.

2. Catheter-Based Procedures

• Minimally invasive interventions using a catheter inserted into the heart to repair defects (e.g., closing septal defects, widening valves).

3. Surgery

• Open-heart surgery may be required for complex conditions such as TOF, TGA, or HLHS.
• Some children may need multiple surgeries over time.

4. Heart Transplant

• In rare cases, children with severe CHD that cannot be surgically corrected may require a heart transplant.

5. Lifelong Follow-Up and Care

• Many people with CHD require regular check-ups with a cardiologist throughout their lives.

Some may develop heart rhythm problems (arrhythmias) or heart failure later in life.

Advancements in medical care mean that many children with CHD go on to lead full and active lives.

Key Facts
•       CHD is the most common birth defect in the UK.
•       Over 80% of babies born with CHD now survive into adulthood.
•       Approximately 13 babies per day are born with CHD in the UK.