Atrial septal defect is a congenital heart defect characterized by a hole in the wall (or the septum) of the left and right atrium.
The hole present in the heart during fetal development is known as foramen ovale but this closes during birth. In atrial septal defect, the openings of the heart during fetal development do not close after birth. As a result, a hole would be present in the wall that separates the right and left atrium. Based on a 2019 study, 1 of every 1,859 babies born in the United States each year are born with an atrial septal defect (CDC.gov).
This hole increases blood flow that passes through the pulmonary vessels. After a few years, damage may occur on these vessels and cause the following:
- Abnormal heartbeat
- Stroke
- Heart Failure
- Increased blood flow to the lungs
Etiology of Atrial Septal Defect
- Mendelian inheritance
- Aneuploidy
- Transcription errors
- Mutations
- Pregnant mother’s exposures
Types of Atrial Septal Defect
- Ostium secundum – the location is at the atrial septum (very common)
- Ostium primum – it is located in the lower portion of the atrial septum. Usually accompanies defects to the mitral valve and tricuspid valve
- Sinus venosus – it can be seen at the top of the atrial septum. This anomaly shows defects that have displaced pulmonary veins. (pulmonary veins are supposed to be to the left but it is seen at the right atrium)
Normal Fetal Circulation
The placenta is the main support of the fetus throughout pregnancy. Deoxygenated blood passes from the fetus to the mother through the placenta by the umbilical cord.
When blood enters the fetus through the placenta, the blood gets oxygen from the placenta and travels through the umbilical cord vessels, the third vessel to be exact. Oxygenated blood or blood with oxygen will now pass through the umbilical vein passing through the liver of the fetus and then will go in via the right side of the heart.
This is the normal blood flow after birth. In the normal blood flow of the heart after birth, the deoxygenated blood travels from the body to the heart, then to the lungs to be oxygenated, and then back to the heart then to the body delivering oxygenated blood to the whole body.
Foramen ovale and ductus arteriosus are both openings in between the atrium and the pulmonary veins, respectively. The fetus is not using the lungs because the placenta mainly supports it. However, these openings close moments after birth or anytime after birth when the placenta is clamped, then the lungs would start working, pumping out the fluid first, then the cycle of oxygenation begins.
2 different types of defects when the septum doesn’t close:
- Patent foramen ovale, otherwise known as PFO
- Atrial Septal Defect also known as ASD
Signs and Symptoms
- Murmurs
- Abnormal cardiac impulse
- Rapid and irregular heart rhythm
- Cyanosis (blue colored skin and nails)
- Shortness of breath with or without activity
- Cough
- Getting dizzy
- Fainting
- Fatigue
- Hands, face, or leg swell
- Loss of appetite
- Adults: are asymptomatic for several years
Diagnosis
If the child is suspected to have ASD, they will undergo tests such as:
- Echocardiography – transthoracic
- Transesophageal (TEE) and intracardiac echocardiography
- Angiography (cardiac catheterization)
- Magnetic Resonance Imaging
Treatment
- Medication – medications do not close the hole but these drugs help in managing the signs and symptoms of ASD. Complications may arise after surgery, so these drugs may help in minimizing the effect after the surgical procedure. The medications that are used are beta-blockers (maintains regular heartbeat) and anticoagulants (lessen the possibility of forming blood clots)
- Surgery
- Cardiac catheterization
- Open-heart surgery
Nursing Interventions for Atrial Septal Defect
- Nurses have to eliminate the risk of injury for patients having atrial septal defects during surgery and after surgery. They have to:
- Assess toxicity for drugs as this may cause sudden heart failure if not prevented
- Monitor diagnostic tests
- Educate the family about the surgery and the possible outcomes. Be a support person for the family and keep the family informed of the prognosis, may it be for long-term or short-term care
- If a child is to undergo surgery, use a play doll to prepare the child
- Give instructions to the family on how to monitor a patient’s apical pulse when giving medications for the heart (withhold if the apical pulse is less than 70-80 for children and 90-100 for infants). Inform them to call their physician right away when they notice an irregular pulse or low pulse for this is the sign of toxicity to the medication
