Congenital heart disease

Common types of cyanotic congenital heart disease include:

• Hypoplastic left heart syndrome (HLHS): This improper formation of the left side of the heart means only one side of the heart can pump blood to the body while blood must flow passively to the lungs. HLHS can lead to underdevelopment in many areas of the heart, including the left ventricle, mitral valves, and aortic valves.
• Pulmonary atresia: This defect occurs when the pulmonary valve that controls blood flow from the heart to the lungs fails to form.
• Total anomalous pulmonary venous return (TAPVR): This condition occurs when babies are unable to return oxygen rich blood from the lungs to the heart so that it may be pumped to the body.
• Transposition of the great vessels: This occurs when the main pulmonary artery and the aorta, two major arteries that deliver blood from the heart to the rest of the body, are switched causing deoxygenated blood to be delivered to the body.
• Tricuspid atresia: This defect occurs when the valve that controls blood flow from the upper to the lower right chambers of the heart fails to form and is missing.
• Truncus arteriosus: This condition occurs when the blood vessel between the aorta and the pulmonary artery fails to separate during fetal development. It can result in excess blood going to the lungs, forcing the heart to work harder to pump oxygen-rich blood to the rest of the body.

Common types of non-cyanotic congenital heart disease include:

• Aortic valve stenosis: This occurs when the aortic valve, between the aorta and a heart chamber on the lower left, is constricted and fails to open completely. This restricts blood flow from the heart to other parts of the body.
• Bicuspid aortic valve (BAV): This condition is caused when the aortic valve develops with two cusps (flaps of tissue) instead of three. BAV can lead to blood leakage (aortic regurgitation) or narrowing (aortic stenosis) of the valve, leading to inadequate blood flow.
• Atrial septal defect (ASD): This condition is caused by a hole in the wall that separates the heart’s upper chambers. It occurs when holes made during the heart’s formation fail to close before birth.
• Partial anomalous pulmonary venous return (PAPVR): Similar to TAPVR, a limited number of pulmonary veins return to the right instead of the left side of the heart, returning oxygen rich blood to the right atrium to be circulated to the lungs to pick up oxygen.
• Atrioventricular septal defect (AVSD): This condition, also known as endocardial cushion defect, is caused by a hole in the chambers between the left and right sides of the heart. It often causes improper formation of the valves that control blood flow between these chambers.
• Coarctation of the aorta: This abnormal narrowing of the aorta can cause elevated blood pressure and, in extreme cases, heart failure. It may go undetected until adulthood.
• Patent ductus arteriosus: This condition occurs in babies when a blood vessel, called the ductus arteriosus, doesn’t close as it should shortly after birth.
• Pulmonic stenosis: This occurs when the pulmonary valve narrows and can’t deliver enough oxygen in the blood.
• Ventricular septal defect (VSD): This condition is caused by a hole in the wall between the heart’s two lower chambers.

Some conditions can be either cyanotic or non-cyanotic such as

• Ebstein anomaly: This condition occurs when the valve between the upper and lower right heart chambers fails to form properly. Blood leaks between the chambers due to the malfunctioning valve, impacting blood flow.
• Tetralogy of fallot: This occurs when a baby experiences four distinct heart defects simultaneously (ventricular septal defect, overriding aorta, pulmonary stenosis, and right ventricular hypertrophy). Patients may present cyanotic if they have severe pulmonary stenosis or obstruction to pulmonary blood flow.