Everything You Need To Know About Congenital Heart Defects

Congenital heart defects are abnormalities of the heart that develops before birth. It is one of the most common types of birth defects. It is a range of heart disorders that affect the normal workings of the heart. 

A congenital heart defect is generally divided into two groups according to the flow of blood:

  • Cyanotic heart defects: is when deoxygenated blood enters circulation and cause cyanosis (blue-tinted skin). Blood flows from the right part of the heart to the left part of the heart.
  • Non-cyanotic heart defects: is the flow of blood from the left side to the right side of the heart.

Most Common Types Of Congenital Heart Defects

Septal defects:

Septal defects are the abnormal connection (hole) in the wall (septum) between the chambers of the heart. There are two common types:

  • Atrial septal defect: It is the formation of an abnormal connection between the left and the right atrium. The flow of blood between both chambers through this abnormal hole formation causes the receiving chamber to stretch and become enlarged.
  • Ventricular septal defect: it is the abnormal connection between the left and right ventricles. This connection causes the flow of blood between both chambers and into the lungs as well. The extra blood flows into the lungs causes increase pressure in the lungs.

Tetralogy of Fallot

Tetralogy of Fallot is the combination of 4 different disorders:

  • Ventricular septal defects.
  • Overriding aorta: It is the shifting of the aorta from its normal position to the right, and it lies directly above the ventricular septal defect (VSD)
  • Right ventricular hypertrophy: It is the thickening of the right ventricular wall due to the over-pumping of blood done by the heart (when the heart works too much).
  • Pulmonary valve stenosis: It is the narrowing of the pulmonary valve.

Aortic valve stenosis

Aortic valve stenosis is the narrowing and stiffening of the aortic valve. It is a valve that allows blood to flow from the heart to the aorta. The aorta is the primary artery that carries blood to the entire body.

Pulmonary Aortic valve stenosis

Pulmonary valve stenosis is the pulmonary valve that controls the flow of blood from the right ventricle to the lungs.

Coarctation of aorta

Coarctation of aorta is the narrowing of the aorta.

Patent ductus arteriosus:

Patent ductus arteriosus is the opening of the ductus arteriosus after birth. The ductus arteriosus is the blood vessel that connects the pulmonary artery to the aorta before birth. Ductus arteriosus is supposed to close up between 2 – 3days after birth, but in patent ductus arteriosus, it doesn’t close up.

Ebstein’s anomaly/Tricuspid atresia

Ebstein’s anomaly/Tricuspid atresia is the abnormal development of the tricuspid valve. The tricuspid valve is the valve that connects the right atrium and the right ventricle.

Hypoplastic left heart syndrome

Hypoplastic left heart syndrome is a not normally development of the left side of the heart that causes the left side of the heart to be small.

Transposition of great arteries

Transposition of great arteries is the swapping of position between the aorta and the pulmonary artery. This leads to the wrong connection of the vessels to the chambers (The aorta connects to the right side of the heart, and the pulmonary artery connects to the left side of the heart).

Partial or total anomalous pulmonary venous connection (TAPVC)

The partial or total anomalous pulmonary venous connection is the abnormal connection of the four veins that carry oxygen-filled blood from the lungs to the left side of the heart. In TAPVC, the four veins connect to the right side of the heart.

Truncus arteriosus 

Truncus arteriosus is the abnormal development of the pulmonary artery and the aorta that leads to the joining of both vessels (which means both vessels become one single vessel).

Causes And Risk Factors Of Congenital Heart Defects

There is no known specific cause. Several factors and diseases have been linked to increasing the risk of Congenital heart defect. Factors such as:

  • Alcohol consumption during pregnancy
  • Older age mother (40 and above)
  • Family history of heart defect
  • Maternal infection (during pregnancy) such as rubella
  • Down syndrome
  • Turner’s syndrome
  • Smoking while pregnant
  • Poorly controlled maternal diabetes
  • Use of certain medications during pregnancy, such as statins, acne medications (topical retinoids, isotretinoin), benzodiazepines and ibuprofen
  • Noonan syndrome
  • Influenza (the flu) during the first trimester.
  • Phenylketonuria.
  • Exposure to certain chemicals in large quantities such as in nail polish, paint or glue
  • Maternal obesity
  • Marfan syndrome
  • Parents being closely related by blood for instance parents being cousins
  • Poor nutritional status during pregnancy

Signs And Symptoms Of Congenital Heart Defect

  • Abnormal heart rhythms
  • Cyanosis of the skin (blue-tinted skin)
  • Dyspnea (shortness of breath)
  • Rapid breathing
  • Failure to thrive (poor weight gain)
  • Swelling around the eyes and legs.
  • Palpitations
  • Fatigue (extreme weakness)
  • Irritability
  • Prolonged crying
  • Heart murmur
  • Seizures
  • Fainting
  • Unusually large toe and fingernails
  • Clubbing of fingers and toes (abnormal round shape of the nail bed)

Diagnosis Of Congenital Heart Defects

  • Prenatal ultrasound
  • Prenatal fetal echocardiography.
  • Physical examination of the baby after birth will reveal murmurs.
  • ECG: measures the heart’s electrical activity
  • Postnatal Echocardiogram: examine the structure of the heart and nearby vessels
  • Pulse oximetry: measures oxygen saturation
  • Chest X-ray

Treatment Of Congenital Heart Defects

Management usually involves corrective surgery and medications. A heart transplant is also an option, as well. The approach is determined by the type of the defect, how critical it is, and the child’s age, size, and overall health says the NHS.

Associated Conditions

Congenital heart defects usually don’t stand alone. It is associated with 7 other conditions. These conditions have been termed “VACTERL.” The VACTERL association is made up of:

  1. V – Vertebral anomalies: are a group of spine malformations.
  2. A – Anal atresia: also known as the imperforate anus or anorectal malformations, is a birth defect characterized by narrowing of the anus, colon that is higher in the pelvis, fistula connecting the rectum and bladder and a persistent cloaca. Cloaca is the fusing of rectum, vagina, and the urinary tract creating a single channel.
  3. C – Cardiovascular anomalies: heart disorders.
  4. T – Tracheoesophageal fistula: is an abnormal connection between the trachea and the esophagus.
  5. E – Esophageal atresia: is a malformation of the esophagus that causes the upper esophagus to detach from the lower esophagus and stomach.
  6. R – Renal (kidney) and Radial anomalies.
  7. L – Limb defects: is the abnormal formation of a leg or an arm during the intrauterine growth of a fetus.

Final word

  • Rubella vaccine, intake of iodine, and folic acid can partly prevent Congenital heart defects.
  • Some heart defect does not require surgery, but others can be managed with heart surgery and heart transplant.
  • A congenital heart defect is one of the most common birth defects. It affects 4 -75 children in every 1,000 live births.
  • In a normal healthy fetus, the lungs don’t work before birth, so the ductus arteriosus connects the pulmonary artery to the aorta in other to bypass the non-functioning lungs.
  • In a normal healthy human body, the aorta connects to the left side of the heart, and the pulmonary artery is connected to the right side of the heart.