Congenital heart defects: types, causes, diagnosis and lifelong care

Congenital heart defects are heart problems that a baby is born with. Some are minor, and others need care very soon after birth. This article explains what they are, how they are found and how people live with them, using information from the NHS, the US CDC and NHLBI.

1. Introduction

A congenital heart defect (also called congenital heart disease) forms while the heart is developing in the womb. It can disrupt the way blood flows through the heart and around the body ^{[1, 3]}. NHLBI describes these defects as the most common type of birth defect, affecting about 1 in 100 babies born in the United States. Some are minor and need no treatment, while others are serious ^[3]. The CDC says about 40,000 babies in the United States are born with a heart defect each year, and more than 2 million people there are living with one ^[2]. It estimates that about 1 in 4 babies with a heart defect has a critical defect that needs surgery or other procedures in the first year of life ^[2].

2. Types of heart defect

The most common defects involve the walls inside the heart, the heart valves or the large blood vessels that carry blood to and from the heart ^[3]. The CDC lists examples such as atrial septal defect and ventricular septal defect, which are holes between heart chambers, and critical defects such as tetralogy of Fallot, hypoplastic left heart syndrome and coarctation of the aorta, which is a narrowing of the main artery ^[2]. Treatment depends on the type. Some babies need surgery soon after birth, while a small hole may need no treatment at all ^[1].

3. Causes and risk factors

The CDC says that for most babies the cause is unknown. Some defects come from changes in genes or chromosomes ^[2]. The NHS and CDC list these factors linked with a higher risk ^{[1, 2]}:

• The mother having diabetes before pregnancy or during pregnancy
• Obesity in the mother
• Smoking or second-hand smoke exposure during pregnancy
• Certain medicines taken during pregnancy
• Infections such as rubella during pregnancy ^[1]
• A family history of heart defects ^[3]

Tell your doctor about all medicines before and during pregnancy, and never stop one without advice.

4. Signs and symptoms

Signs depend on the type and severity, and some defects cause few or none ^[2]. The CDC and NHS describe ^{[1, 2]}:

• Bluish or greyish lips, skin or nails, called cyanosis
• Fast or laboured breathing
• Tiredness or trouble feeding, and slow weight gain
• Swelling of the tummy, hands, ankles or feet
• Excess sleepiness

Some people only notice symptoms as teenagers or adults, such as tiredness, shortness of breath and palpitations ^[1]. A heart murmur, an unusual heartbeat sound found with a stethoscope, is common ^[1].

5. Diagnosis and tests

Some defects are found before birth. The CDC says a fetal echocardiogram, a special ultrasound of the baby's heart, can detect them ^[2]. The NHS notes the 20-week pregnancy scan screens for heart problems but can miss them, and some people are diagnosed only as adults ^[1]. Newborns have pulse oximetry, a simple bedside test that estimates blood oxygen levels. Low readings can show a critical defect, allowing early treatment ^[2]. Other tests include an ECG, chest X-ray, MRI, echocardiogram and angiography, a test that images the blood vessels ^[1].

6. Treatment and management

People are referred to a specialist heart team. Some people need only regular check-ups ^[1]. Options include medicines, keyhole or open-heart surgery, and in rare cases a transplant ^[1]. The CDC also describes cardiac catheterisation, where a thin tube is guided through blood vessels to the heart for measurement, imaging or repair. Some defects cannot be fully repaired, but procedures can improve blood flow and heart function. Even after repair, many people need lifelong follow-up with a cardiologist ^[2].

7. Living with a heart defect

The NHS advises ^[1]:

• Keeping a healthy weight, eating a balanced diet and staying active at the level your care team recommends
• Looking after your teeth
• Avoiding smoking, vaping, illegal drugs and heavy alcohol
• Telling your care team if you are pregnant or planning pregnancy

Possible complications include heart failure, infection inside the heart, high blood pressure in the lung arteries and stroke ^[1]. NHLBI says routine follow-up and attention to mental health can reduce complications and improve quality of life ^[3].

NHLBI lists a family history of heart defects as a known risk factor, so tell your doctor if heart defects run in your family ^[3]. The CDC says many people still have heart problems after surgical repair and may develop other health problems over time, so routine check-ups with a cardiologist are recommended ^[2]. Ask your care team about activity, dental care and pregnancy planning that suit your own heart condition.

8. When to see a doctor

If you suspect a heart defect but it is not an emergency, the NHS advises asking for an urgent GP appointment or contacting NHS 111, which is a UK service ^[1]. The NHS advises calling for emergency help if lips or skin suddenly turn blue or grey, there is difficulty breathing, chest pain, confusion, dizziness, drowsiness, irregular heart rhythms, or a child is limp or not responding. Do not drive yourself to hospital ^[1].

In an emergency, call your local emergency number (112 in India, 911 in the United States).

9. Conclusion

Congenital heart defects range from mild to severe, and most have no clear cause. Screening before and after birth helps find serious defects early. With specialist care and regular follow-up, many people live longer and healthier lives. The care team decides which treatment is right.