Congenital Heart Disease

Congenital heart disease (CHD) is a term used to describe a range of heart defects that occur at birth due to abnormalities in the heart’s structure or function. These defects can impact the heart’s ability to pump blood effectively, leading to reduced oxygen supply to the body. CHD is the most common birth defect worldwide, affecting approximately 1 in 100 newborns.

The prevalence of CHD varies depending on the type and severity of the defect. Some defects are mild and require no treatment, while others can be life-threatening and require immediate medical intervention. According to the Australian Institute of Health and Welfare (AIHW), around 9 in every 1,000 babies born around the world are affected by congenital heart disease, with an estimated 2,400 babies affected in Australia.

The impact of CHD on individuals and society can be significant. Infants and children with CHD may experience developmental delays, poor growth, and decreased quality of life. Adults with CHD may experience complications such as heart failure, arrhythmias, and stroke. The economic impact of CHD is also significant, with healthcare costs for CHD estimated to be in the billions of dollars each year.

Despite the challenges associated with CHD, advances in medical technology have improved survival rates and quality of life for individuals with the condition. With appropriate medical care and support, many individuals with CHD can lead healthy and fulfilling lives.

What causes congenital heart disease?

The exact causes of CHD are not always clear, but they are believed to be a combination of genetic and environmental factors. Here are some factors that may contribute to the development of CHD:

• Certain genetic conditions such as Down syndrome, Turner syndrome, and Marfan syndrome are associated with an increased risk of CHD.
• Factors that affect maternal health during pregnancy, such as uncontrolled diabetes, rubella infection, or use of certain medications or drugs, can increase the risk of CHD in the developing fetus.
• Exposure to certain environmental factors such as tobacco smoke, alcohol, and certain chemicals may increase the risk of CHD.

It’s important to note that most cases of CHD occur in individuals with no known family history of the condition, indicating that genetic factors alone are not always sufficient to cause CHD. Additionally, many infants born with CHD have no identifiable risk factors, suggesting that the causes of CHD are complex and multifactorial.

What types of congenital heart diseases are there?

There are many different types of congenital heart disease (CHD), ranging from mild to severe. Here are some common types of CHD:

Atrial septal defect

Atrial septal defect (ASD) is a type of congenital heart defect in which there is a hole in the wall that separates the two upper chambers (atria) of the heart. This hole allows oxygen-rich blood from the left atrium to flow into the right atrium, where it mixes with oxygen-poor blood. This can cause the heart to work harder than normal and may lead to problems such as heart failure, pulmonary hypertension, and arrhythmias.

ASD can range in size from very small to very large, and some may close on their own without treatment. However, larger defects or those that cause symptoms may require surgical repair.

Ventricular septal defect

Ventricular septal defect (VSD) is a common type of congenital heart defect where there is a hole in the wall (septum) that separates the two lower chambers (ventricles) of the heart. This hole allows oxygen-rich blood from the left ventricle to mix with oxygen-poor blood from the right ventricle, leading to an increase in blood volume in the lungs and overworking of the heart.

Small VSDs may close on their own or cause no symptoms, while larger VSDs can lead to symptoms such as shortness of breath, fatigue, rapid breathing, and poor growth.

Patent ductus arteriosus

Patent ductus arteriosus (PDA) is a type of congenital heart defect that occurs when the ductus arteriosus, a blood vessel that is open during foetal development to allow blood to bypass the lungs, fails to close shortly after birth. As a result, some of the oxygen-rich blood from the aorta flows back into the pulmonary artery and into the lungs, leading to an increase in blood flow to the lungs. This can cause the heart to work harder than normal, and can lead to complications such as heart failure, respiratory distress, and poor growth.

In some cases, PDA may close on its own within the first few months of life. However, in other cases, treatment may be necessary to close the PDA and prevent complications.

Tetralogy of fallot

Tetralogy of Fallot (TOF) is a type of congenital heart defect that affects the structure of the heart and the way blood flows through it. It is one of the most common types of cyanotic heart disease, which means that it reduces the amount of oxygen in the blood.

TOF is a combination of four heart defects, which include:

• Ventricular septal defect: a hole in the wall that separates the two lower chambers of the heart.
• Pulmonary stenosis: a narrowing of the pulmonary valve or the blood vessels that carry blood from the heart to the lungs.
• Overriding aorta: a misplacement of the aorta, the main artery that carries blood from the heart to the body, over the ventricular septal defect.
• Right ventricular hypertrophy: thickening of the muscle in the right ventricle due to increased workload caused by the other defects.

Transposition of the great arteries

Transposition of the great arteries (TGA) is a congenital heart defect in which the two main arteries leaving the heart, the pulmonary artery and the aorta, are switched (or transposed). In a normal heart, the pulmonary artery carries oxygen-poor blood from the heart to the lungs, where it is oxygenated, and the aorta carries oxygen-rich blood from the heart to the rest of the body.

In TGA, the pulmonary artery is connected to the left ventricle (the chamber that normally pumps oxygen-rich blood to the body) and the aorta is connected to the right ventricle (the chamber that normally pumps oxygen-poor blood to the lungs). As a result, oxygen-poor blood circulates throughout the body, while oxygen-rich blood circulates through the lungs, leading to a lack of oxygen in the body’s tissues and organs.

Coarctation of the aorta

Coarctation of the aorta (CoA) is a congenital heart defect in which there is a narrowing or constriction of the aorta, the main artery that carries oxygen-rich blood from the heart to the rest of the body. This narrowing can occur anywhere along the aorta, but is most commonly found near the ductus arteriosus, a blood vessel that connects the pulmonary artery to the descending aorta before birth.

The constriction of the aorta causes the heart to work harder to pump blood through the narrow opening, which can lead to high blood pressure in the upper body and low blood pressure in the lower body. If left untreated, CoA can lead to complications such as heart failure, aneurysm, and stroke.

Hypoplastic left heart syndrome

Hypoplastic left heart syndrome (HLHS) is a rare and serious congenital heart defect in which the left side of the heart is severely underdeveloped. In a normally developed heart, the left side is responsible for pumping oxygen-rich blood from the lungs out to the body. In HLHS, the left ventricle (the heart’s main pumping chamber) is small and weak, and cannot perform this function effectively.

As a result, the right side of the heart must work harder to compensate, leading to a range of symptoms including difficulty breathing, poor feeding, and low oxygen levels in the body. Without treatment, HLHS can be fatal in the first few weeks of life.

What are the symptoms of congenital heart disease?

The symptoms of CHD can vary widely depending on the type and severity of the heart defect. Some people with CHD may have no symptoms or only mild symptoms, while others may experience more severe symptoms that affect their daily life. 

Some common symptoms associated with CHD include:

• Cyanosis (a bluish tint to the skin, lips, and nails due to low oxygen levels in the blood)
• Shortness of breath or rapid breathing
• Poor feeding or difficulty gaining weight
• Fatigue or weakness, especially during physical activity
• Chest pain or discomfort
• Abnormal heart rhythms (arrhythmias)
• Swelling in the legs, ankles, or feet
• Clubbing of the fingers and toes (widening and rounding of the tips of the fingers and toes due to lack of oxygen)
• Fainting or loss of consciousness

It’s important to note that some people with CHD may not experience symptoms until later in life, while others may have symptoms from birth. If you or your child has been diagnosed with CHD or are experiencing any of these symptoms, it’s important to speak with a healthcare provider for evaluation and treatment.

How is congenital heart disease diagnosed?

Congenital heart disease (CHD) can be diagnosed before birth, shortly after birth, or later in life. The specific diagnostic tests and procedures used will depend on the type and severity of the heart defect. 

Here are some common methods used to diagnose CHD:

• Prenatal ultrasound: A non-invasive imaging test that uses high-frequency sound waves to create images of the developing fetus’s heart. This can help detect many types of heart defects before birth.
• Echocardiogram: A non-invasive imaging test that uses sound waves to create detailed images of the heart’s structure and function. This test can be performed on infants, children, and adults to diagnose and monitor CHD.
• Electrocardiogram (ECG): A test that measures the electrical activity of the heart to detect abnormal heart rhythms or other signs of heart disease.
• Chest X-ray: A test that uses low-dose radiation to create images of the heart and lungs. This can help identify certain types of heart defects and complications.
• Cardiac catheterization: A minimally invasive procedure that involves inserting a thin, flexible tube (catheter) into a blood vessel and threading it to the heart. This test can provide detailed information about the heart’s structure and function, as well as help guide certain treatments.
• MRI or CT scan: Advanced imaging tests that can create detailed 3D images of the heart and blood vessels. These tests are typically reserved for more complex or challenging cases.

How is congenital heart disease treated?

The treatment options for CHD depend on the type and severity of the heart defect. In some cases, no treatment may be necessary, while in others, surgery or other interventions may be required. 

Common treatment options for CHD include;

Medications

Here are some examples of medications that may be used:

• Diuretics: These medications help reduce fluid buildup in the body and are often used to treat heart failure or other conditions that cause fluid retention.
• ACE inhibitors or ARBs: These medications help lower blood pressure and can be used to treat conditions such as heart failure due to a poorly contracting left ventricle or hypertension secondary to coarctation of the aorta.
• Beta blockers: These medications help slow the heart rate and reduce the workload on the heart. 
• Anticoagulants: These medications help prevent blood clots and are often used in people with certain types of CHD, such as those with atrial fibrillation or a mechanical heart valve.
• Oxygen therapy: Supplemental oxygen may be used to help improve oxygen levels in the blood and reduce the workload on the heart in people with certain types of CHD.

Catheter-based procedures

Some types of CHD can be treated with minimally invasive procedures that involve threading a catheter (thin tube) through a blood vessel to the heart. These procedures can often be done without the need for open-heart surgery and may include techniques such as balloon angioplasty of a pulmonary stenosis or coarctation of the aorta or closure of a patent ductus arteriosus (PDA).

Surgery

For more complex or severe heart defects, surgery may be necessary to repair or replace damaged heart structures. This can involve open-heart surgery, in which the chest is opened to access the heart, or minimally invasive techniques that involve smaller incisions. 

Heart transplant

In some cases, a heart transplant may be necessary for people with CHD who have severe heart failure or other complications.

Lifestyle modifications

In addition to medical or surgical treatments, people with CHD may need to make lifestyle modifications to manage their condition. This may include avoiding strenuous physical activity, following a heart-healthy diet, and managing any other health conditions.

It’s important to work closely with a team of healthcare providers who specialise in heart care to determine the best treatment plan for your specific type of CHD. With proper treatment and management, many people with CHD are able to lead full, healthy lives.

Where can I go if I suspect I have congenital heart disease in Melbourne?

If you are experiencing symptoms associated with CHD, you can receive diagnosis and treatment at HeartWest.

HeartWest is the largest cardiology group in the western and northwestern corridors of Melbourne, with 4 major locations and 3 satellite sites. 

At HeartWest, our qualified experts will provide you with the best cardiology care. You will experience nothing but professionalism, care and courtesy; from your first interaction with our staff, to going through tests, procedures and consultations.

Our cardiologists have expertise in all fields of adult cardiology, including; 

• General cardiology
• Heart failure
• Cardiac imaging (including stress echocardiography)
• Interventional cardiology
• Electrophysiology & pacing
• Cardiothoracic surgery

Contact us for efficient and affordable specialist heart care services.