Newborn heart problems are more common than you would expect. According to the American Heart Association, nine out of every 1,000 babies in the United States are born with a congenital heart defect. Although most congenital heart defects are harmless, some are dangerous malformations that require surgery.
Types
Certain defects force blood toward the lungs, in what is known as a left-to-right shunt pattern. This is where the oxygenated blood is sent to the right side of the heart, where it mixes with the deoxygenated blood from the body. These are known as acyanotic heart lesions or obstructive defects.
Other disorders produce a right-to-left movement of blood. These are the cyanotic defects or blue baby syndromes, where the oxygenation of the blood is so reduced that the infant turns blue. These malformations are serious and can lead to death.
Causes
Most congenital heart defects occur when the fetal heart development is disturbed somewhere between three weeks after conception and the 12th week of gestation.
Maternal factors, family history or chromosomal abnormalities can play a role in the defect.
Maternal factors can include a pregnant mother contracting the rubella virus known as German measles, or taking prescribed medications such as the anticonvulsants trimethadione, valproic acid, phenytoin and carbamazepine, the antipsychotic agent lithium and the acne drug isoretinon during the first trimester. Other causes are when a mother has medical conditions such as systemic lupus erythematous, phenylketonuria and uncontrolled diabetes.
Moreover, if the mother smokes, drinks alcohol or takes recreational drugs such as cocaine or heroin, she severely increases the likelihood her baby is born with a malformed heart.
A family history of heart defects also increases the risk that each child inherits a heart problem by 50 percent.
Lastly, chromosomal abnormalities are random mutations of the fetus' genetics that can cause heart problems along with defects in other areas of the body.
Clinical Manifestations
Some infants with congenital heart problems show no symptoms with their defect. Other symptoms that do show in children are shortness of breath, difficulty feeding, failure to thrive, lack of energy, low blood pressure, prolonged fever and cyanosis--a bluish tint to the skin seen especially around the lips and on the extremities.
Most congenital cardiac disorders are easily discovered by medical practitioners because of their distinctive sounds known as heart murmurs.
Holes in the Heart
The most common heart problems are holes in the heart, known as septal defects. These are atrial septal defects or ASD, the ventricular septal defects or VSD, and the patent ductus arteriosis or PDA, although this is not technically a hole within the heart.
These defects, except PDA, are openings within the heart wall that separates the upper or lower chambers of the heart.
As acyanotic conditions, these openings produce a left-to-right shunt pattern. Generally, babies have no symptoms, but some do. Their defects can be treated with medications such as indomethacin or ibuprofen for PDA, or with surgery for VSD and ASD.
Valvular Defects
Various combinations of heart valve malformations can occur, but the most common are pulmonic valve stenosis and aortic stenosis. Known as the obstructive heart lesions, valvular disorders are considered part of the acyanotic class. These defects are characterized by a narrowing of the heart valve openings with faulty valve leaflets.
Often babies with these heart problems grow into adulthood without experiencing any major symptoms. Associated with anticonvulsants in utero, these defects are treated with a heart catherization technique called balloon angioplasty or, in more severe cases, open heart surgery.
Blue Baby Syndromes
The cyanotic heart lesions, or more commonly known as the blue baby syndromes, are the most dangerous neonatal heart problems. They are caused by genetic mutations.
These malformations are usually discovered during pregnancy by fetal sonography or immediately after birth when the newborn shows the characteristic coloring and difficulty breathing. Treatment for these conditions is emergent open heart surgery.
References
- "Congenital Diseases of the Heart: Clinical-Physiological Considerations" 3rd ed.; Abraham Rudolph, MD; 2009
- "Pediatric Cardiology"; Walter Johnson, MD & James Moller, MD; 2001
- "Essential Pediatric Cardiology"; Peter Koenig, MD, & et al.; 2004
- "Pediatrics"; Cri du Chat Syndrome and Congenital Heart Diseases: A Review of Previously Reported Cases and Presentation of an Additional 21 Cases From the Pediatric Cardiac Care Consortium; Christine Hills, MD, & et al.; May 5, 2006
- "Maternal-Fetal Medicine: Principles and Practice" 5th ed.; Robert Creasy, MD & Robert Resnik, MD eds.; 2004
