Atrial Septal Defect
Atrial septal defect is a congenital heart anomaly characterized by a hole in the septum, the wall that separates the upper chambers (atria) of the heart. The size of the hole can vary, and it may either close spontaneously or necessitate surgical intervention.
- Secundum ASDs are situated in the center of the atrial septum. This is the most prevalent ASD type, accounting for 80% of all ASDs.
- Primitive ASDs are located in the lower portion of the atrial septum. Babies with ASDs of infancy may also have additional heart defects. Included in this category are endocardial cushion defects, atrioventricular septal defects, tricuspid valve defects, and mitral valve defects. Primitive ASDs are frequently associated with Down syndrome.
- Sinus venosus atrial septal defects are located in the upper or lower back portion of the atrial septum. This type is associated with defects in the right pulmonary vein or the superior or inferior vena cava, which are large veins in the heart.
- Less than 1% of all ASDs are unroofed coronary sinuses. It is characterized by a missing or incomplete wall between the coronary sinus (a group of veins connected to the heart) and the left atrium. It is frequently accompanied by another complex congenital heart disease.
- Secundum ASDs are situated in the center of the atrial septum. This is the most prevalent ASD type, accounting for 80% of all ASDs.
- Primitive ASDs are located in the lower portion of the atrial septum. Babies with ASDs of infancy may also have additional heart defects. Included in this category are endocardial cushion defects, atrioventricular septal defects, tricuspid valve defects, and mitral valve defects. Primitive ASDs are frequently associated with Down syndrome.
- Sinus venosus atrial septal defects are located in the upper or lower back portion of the atrial septum. This type is associated with defects in the right pulmonary vein or the superior or inferior vena cava, which are large veins in the heart.
- Less than 1% of all ASDs are unroofed coronary sinuses. It is characterized by a missing or incomplete wall between the coronary sinus (a group of veins connected to the heart) and the left atrium. It is frequently accompanied by another complex congenital heart disease.
Symptoms of Atrial Septal Defect
Despite the fact that an atrial septal defect is present at birth, many people do not experience symptoms until they are well into adulthood. Because they do not strain the heart or lungs, small ASDs (less than 5 millimeters) may not cause symptoms.
Symptoms of ASD in children
The majority of children exhibit no symptoms. A heart murmur is the most common (and often the only) symptom of heart disease. Upon listening to the patient’s heart with a stethoscope, a healthcare professional will detect this condition.
When children experience additional symptoms, they include:
- Being underweight
- Growth delays
- Frequent respiratory infections
Symptoms of ASD in adults
Adults with ASD may exhibit symptoms as early as age 40. Depending on how much the ASD has strained the heart and lungs, symptoms will vary. They consist of:
- Fatigue.
- Breathlessness during exercise.
- Heart palpitations
- Rapid heart rate (tachycardia).
- Inflammation of the arms and legs.
- Blue complexion (cyanosis).
Causes of Atrial Septal Defect
The precise cause of atrial septal defects is uncertain. However, congenital heart defects are frequently the result of genetic alterations that occur before birth. Some ASD-associated genetic mutations affect the NKX2.5/CSX and TBX5 genes.
Some factors can increase the likelihood of having a child with congenital heart disease. These elements include:
- Alcohol consumption.
- Cigarette and tobacco use.
- Taking specific prescription drugs.
Complications of Atrial Septal Defect
Some infants with an atrial septal defect are also born with additional heart defects or genetic disorders. Among the associated heart defects are:
- Mitral valve disease.
- Pulmonary stenosis.
- Ventricular septal defect (VSD).
Among the associated genetic disorders are:
- Holt-Oram syndrome.
- Down syndrome.
- Thrombocytopenia-absent radii (TAR) syndrome.
Diagnostics of Atrial Septal Defect
Your healthcare provider will conduct one or more tests in order to diagnose you with an ASD and determine how it affects your heart. These consist of:
- Electrocardiography/electrocardiography (ECG/EKG) An ECG displays the electrical activity of the heart. It can reveal whether you have arrhythmia or other electrical problems with your heart.
- Chest radiograph. This examination will reveal whether your right atrium and right ventricle are enlarged. It will also reveal whether your pulmonary blood vessels are affected.
- Echocardiography of the chest (TTE). This test reveals how the ASD-caused left-to-right blood shunt affects your heart. It can also display information regarding pulmonary hypertension.
- Echocardiography via transesophageal echocardiography (TEE). A TEE is an ultrasound performed via the esophagus. It displays the size, location, and shape of an ASD. It can also evaluate the heart valves. TEE is frequently utilized during ASD surgical procedures and percutaneous repairs.
- Echocardiography within the heart (ICE). This is an ultrasound image of the heart. A tiny camera (echo probe) is sent through a peripheral vein to the heart. This test determines the size, shape, and direction of blood flow across the ASD. It is frequently utilized during percutaneous (nonsurgical) ASD repair.
- In certain instances, cardiac CT or heart MRI may be utilized. They are most beneficial for individuals with associated defects or rarer forms of ASD.
Treatment of Atrial Septal Defect
Percutaneous (nonsurgical) ASD repair
This type of repair closes the hole in your atrial septum using a device called a septal occluder. The device is positioned using a catheter, a long, thin tube. The occluder is attached to the catheter, which is guided through a vein in the groin to the heart. Released from the catheter, the occluder opens and seals the hole. Over time, tissue grows over the occluder and it becomes an integral part of the heart.
The vast majority of secundum ASDs and some sinus venosus ASDs can be closed percutaneously. Therefore, this is the most common method.
Before the repair, a cardiac catheterization will be performed to determine the size and location of the ASD and to measure heart pressures.
You will take blood-thinning medication (anticoagulant or antiplatelet) after the repair to prevent blood clots from forming on the device (a possible but rare complication). Your healthcare provider will discuss the best medication for you and how long you should take it.
Surgical repair of ASDs
Primary ASDs, coronary sinus defects, and the majority of sinus venosus ASDs require surgery. These are uncommon conditions that necessitate the intervention of a cardiac surgeon with expertise in congenital heart disease. For some patients, robotic-assisted surgery or minimally invasive surgery may be options.
The ASD is typically closed using a tissue patch during surgical repair. The tissue typically originates from your own pericardium (the membrane around your heart). Some secundum ASDs can be closed surgically with sutures alone and no patch.
