Cyanotic heart disease (CHD) – Types, Causes, and Treatment

What is Cyanotic heart disease?

Cyanotic heart disease (CHD) involves heart defects that reduce the amount of oxygen delivered to the rest of your body. It’s sometimes called critical congenital heart disease. When a baby is born with CCHD, their skin has a bluish tint, called cyanosis.

CHD is often treatable if detected early. It can encompass abnormalities in the rhythm of the heart, as well as a wide array of structural heart problems. These problems can range from mild (never requiring cardiac surgery), to severe (requiring multiple different stages of open heart surgeries). CHD can involve abnormal or absent chambers, holes in the heart, abnormal connections in the heart, and abnormalities in the function or squeeze of the heart. Most congenital heart conditions affect patients from childhood through adulthood.

Some babies affected with CHD can look and act healthy at first, but within hours or days after birth they can have serious complications. Pulse oximetry newborn screening is a non-invasive test that measures how much oxygen is in the blood and can help to identify babies that may be affected with CHD before they leave the newborn nursery. If detected early, infants affected with CHD can often be treated and lead longer, healthier lives.

Etiology

The etiology of CHD is still largely unknown. Many cases of CHD are multifactorial and result from a combination of genetic predisposition and environmental risk factors. CHD is usually isolated and sporadic, but it can also be associated with genetic syndromes. Approximately 15% to 20% of infants with CHD are related to known chromosomal abnormalities, most of these are aneuploidies (trisomy 21, 13, and 18 and Turner syndrome). Potential environmental risk factors include maternal illnesses, including diabetes and phenylketonuria, maternal exposure to toxins or drugs and viral infections during pregnancy.

Types of Cyanotic heart disease

There are three different types of cyanotic heart disease:

Left heart obstructive lesions

These congenital heart defects reduce blood flow between your heart and the rest of your body (systemic blood flow). Specific conditions include:

Hypoplastic left heart syndrome: Hypoplastic left heart syndrome (HLHS) involves underdeveloped structures in the left side of your heart. The left side of your heart is too small to pump enough blood to the rest of your body.

Interrupted aortic arch: In interrupted aortic arch, your aorta is incomplete.

Right heart obstructive lesions

These congenital heart defects reduce blood flow between your heart and lungs (pulmonary flow). Specific conditions include:

Pulmonary atresia: The pulmonary valve is like a door between the right side of your heart and lungs. With pulmonary atresia (PA), the pulmonary valve doesn’t develop correctly or is blocked.

Tricuspid atresia: The tricuspid valve is between the two chambers (atrium and ventricle) on the right side of your heart. In tricuspid atresia, the valve is not formed correctly. A piece of solid tissue blocks blood flow from the right atrium to the right ventricle.

Tetralogy of Fallot: Tetralogy of Fallot (TOF) is the most common CCHD. It involves four heart defects.

Mixing lesions

The third type of CCHD is called mixing lesions. These heart defects cause your body to mix pulmonary and systemic blood flow. Specific conditions include:

Transposition of the great arteries: In this condition, the two main arteries that leave your heart (the main pulmonary artery and the aorta) are reversed. This defect is your second most common CCHD.

Total anomalous pulmonary venous return (TAPVR): In a baby with TAPVR, oxygen-rich blood doesn’t go from their lungs to the left side of their heart, where it should. Instead, the blood goes to the right side of their heart.

Truncus arteriosus: In truncus arteriosus, you have only one main artery to carry blood to your body and your lungs, instead of two separate arteries.

Risk factors

In many cases, an infant will be born with this disease in association with a genetic factor. An infant is more at risk for CCHD when there’s a family history of congenital heart diseases.

Certain genetic syndromes can be accompanied by defects that cause CCHD. These include:

• Down syndrome
• Turner syndrome
• Marfan’s syndrome
• Noonan syndrome

In some instances, outside factors can cause this disease. If a pregnant woman is exposed to toxic chemicals or certain drugs, her infant may have a higher risk of developing heart defects.

Infections during pregnancy are also a factor. Poorly controlled gestational diabetes can also lead to a higher risk of the infant developing CCHD.

Causes of Cyanotic heart disease

Cyanotic heart diseases may be caused by:

• Chemical exposure
• Genetic and chromosomal syndromes, such as Down syndrome, trisomy 13, Turner syndrome, Marfan syndrome, and Noonan syndrome
• Infections (such as rubella) during pregnancy
• Poorly controlled blood sugar levels in women who have diabetes during pregnancy
• Medications prescribed by your doctor or bought on your own and used during pregnancy
• Street drugs used during pregnancy

Symptoms

Signs of a condition are things someone else can see or know about you, like you have a rash or you’re coughing. Some CHDs have no signs, so you may not know that your baby has a CHD until he’s older.

Signs of heart defects include:

• A heart murmur. This is a blowing, whooshing or rasping sound heard during a heartbeat. It’s caused by rough blood flow through the heart valves or near the heart. Your baby’s provider may hear a murmur when she checks your baby’s heartbeat using a stethoscope.
• A pounding heart
• A weak pulse
• Gray or blue color of the skin, lips or fingernails
• Sleepiness while feeding or being very sleepy at other times
• Swollen belly or legs or puffiness around the eyes
• Trouble breathing or fast breathing. Breathing problems while feeding can lead to slow weight gain.

Cyanotic heart disease complications

Complications of cyanotic heart disease include:

• Abnormal heart rhythms and sudden death
• Long-term (chronic) high blood pressure in the blood vessels of the lung
• Heart failure
• Infection in the heart
• Stroke
• Death

Diagnosis and test

Your child’s doctor may suspect cyanotic heart disease after listening to your child’s heart and lungs with a stethoscope, or by noticing their blue appearance. Your child may then be referred to the hospital for further tests to confirm the diagnosis and determine the underlying cause.

Common tests include:

• Chest X-ray
• EKG
• Holter and event monitors
• ECHO
• Cardiac catheterization
• Exercise test

Treatment and medications

The treatment of cyanotic heart disease is based on the severity of the defects in the infant or child:

Catheter: It involves inserting a catheter into an artery or a vein by making a small puncture in the skin. In this procedure there is no need to open the chest and operate directly on the heart, thus recovery is easier and faster. It is the preferred method of treatment in cases of simple heart defects such as pulmonary valve stenosis.

Open-heart Surgery: It is used in cases, which cannot be treated using a catheter to close holes in the heart or to repair/replace heart valves or widen the openings to heart valves.

In severe cases, surgery or a combination of catheter and surgical procedures might be needed to correct the physical defects.

Heart Transplant: This is needed in babies who have multiple heart defects which are complex in nature. In this case, the baby’s heart is replaced with a donor heart from a deceased child.

Medications: Drugs are prescribed based on the nature of the heart defect and the degree of symptoms exhibited. Some of the medications used are ‘diuretics’ to eliminate extra fluids from the body and make breathing easier, anti-arrhythmic drugs to regulate abnormal heart rhythms and increase the strength at which the heart pumps the blood.

Prevention of Cyanotic heart disease

Women who are pregnant should get good prenatal care.

• Avoid using alcohol and drugs during pregnancy.
• Tell your doctor that you are pregnant before taking any prescribed medicines.
• Get a blood test early in the pregnancy to see if you are immune to rubella. If you are not immune, you must avoid any exposure to rubella and should get immunized right after delivery.
• Pregnant women with diabetes should try to get good control over their blood sugar level.

Some inherited factors may play a role in congenital heart disease. Many family members may be affected. If you are planning to get pregnant, talk to your provider about screening for genetic diseases.