Identifying the problem of congenital heart disease
Heart disease is not only a condition of the aged -- children can also have congenital or acquired heart disease. The Jakarta Post's regular contributor on pediatrics Dr. Donya Betancourt discusses the different types of congenital heart disease in the second article of a three-part series.
JAKARTA (JP): Holes in the heart, obstructed blood flow and abnormal blood vessels are the three main types of congenital heart defects, meaning that children are born with them.
A hole in the heart happens in the septum (wall) of the heart chambers or between major blood vessels allowing the heart to mix oxygenated and nonoxygenated blood. The three most common defects are VSD, ASD and PDA.
VSD (ventricular septal defect), which is a hole in the wall between the right and the left ventricle causing blood to move from the left ventricle to the right ventricle because the left ventricle by nature has higher pumping pressure. This defect causes the right side of the heart to work harder as it is overloaded and also causes extra blood to be sent to the lungs which causes high blood pressure and lung congestion. A small VSD may close on it's own without treatment but larger ones may need surgical correction.
ASD (atrial septal defect) is the hole between the right and left atrium which also allows blood to move from the left atrium to the right atrium and it is similar to VSD in that it moves extra blood to the lungs but typically on a more mild basis. In PDA (patent ductus arteriosus, and patent means persistent), the fetus has an opening passage between the pulmonary artery and aorta that allows blood in the fetus to bypass the lungs.
Once the baby is delivered and starts breathing oxygen on his/her own, the pressure in the lungs increases and it closes this opening. In most cases this closure will occur in a few hours after birth but if it does not, oxygen-rich blood will be directed back to the lungs and can cause heart failure in the newborn. Surgery was once required for closing a patent duct but today we have medication that stimulate the ducts to close and surgery is left for the cases where medication fails.
The symptoms in these three groups are similar. Usually, the lungs overload, the degree of overload varies depending on the size of the defect. Typically there are no outward symptoms -- usually the defect is only found by detecting a heart murmur or the child gets tired when feeding and/or sweats profusely. Failure to grow or difficulty in breathing from lung congestion are also good indicators of possible heart problems.
Obstructed blood flow: This condition occurs from blood vessels or valves becoming obstructed or narrowed, resulting in the heart working harder to move blood.
Three common defects are pulmonary stenosis, aortic stenosis and coarctation of aorta. In pulmonary stenosis, the group of patients will typically have blue skin, pulmonary stenosis is the narrowing of the pulmonary valve which is the opening to the right ventricle to the pulmonary vessel, resulting in the muscle of the right ventricle thickening from working harder to send blood through the smaller opening, and causing an inadequate blood supply to the lungs resulting in an inadequate supply of oxygen to the body tissue, causing cyanosis (blue skin).
Aortic stenosis is a narrowing of the aortic valve, the opening of the left ventricle to the aorta. The heart muscle thickens and the ventricle enlarges, the symptoms may vary from no symptom to chest pain during or following vigorous exercise.
Coarctation of aorta is a narrowing of the aorta so it restricts blood flow to the lower part of the body and it causes high blood pressure in the upper part of the body, which is sometimes not diagnosed until later childhood or adulthood. The symptoms of these aortic problem will be a pressure effect; the heart works harder and ventricle gets enlarged also the obstruction results in a back up of blood in the lungs and causes lung congestion with shortness of breath, an inability to eat and no weight gain.
Abnormal blood vessels: This condition mostly involves incorrectly formed or positioned blood vessels going to and from the heart, such as TGA (transposition of the great vessels) and TOF (tetralogy of fallot).
TGA happens when the pulmonary artery leaves the left ventricle and the aorta leaves the right ventricle, resulting in oxygen-rich blood being carried to the lungs instead of the body and oxygen-poor blood being carried to the body. This is a serious and immediately life-threatening defect but most newborns with this defect will also have the opening between the wall of the left and the right sides of the heart allowing the blood to mix but the child will have cyanosis (blue skin) and need corrective surgical treatment.
TOF is found in 10 percent of all congenital heart diseases. There are a combination of 4 defects: a hole in the ventricular septum, a narrowing passage between the right ventricle and pulmonary artery, a shift in the connection of the aorta to the heart and thickened muscle in the right ventricle. This condition results in blue skin because the oxygen-poor blood flows from the right side to the left and out to the body. This condition requires surgical correction.
The third and final part next week will focus on looking for signs of a heart problem in children. Questions? Contact Dr. Donya at drdonya@hotmail.com, or you can reach her at features@thejakartapost.com.