Atrial Septal Defect (ASD) Treatment

Atrial Septal Defect (ASD) is a common congenital (present from birth) heart condition characterized by an abnormal opening in the septum, the wall that divides the heart’s two upper chambers (atria). This condition can vary widely in its presentation, however, in all forms of the condition the impact of the defect allows oxygen-rich blood from the left atrium to mix with oxygen-poor blood in the right atrium, potentially leading to various health issues over time.  

Treatment for Atrial Septal Defect in Cuba is either through minimally invasive catheter-based techniques or traditional surgery based on the size and location of the defect, the presence of symptoms, and the age and overall health of the patient. The benefits of ASD closure are significant, particularly in preventing long-term complications such as: 

• Heart failure 
• Pulmonary hypertension  
• Arrhythmias  
• Stroke 
• Eisenmenger syndrome  

Types of Atrial Septal Defect  

Atrial Septal Defect can vary in size and location within the septum, leading to different types of ASDs. Typically, ASD is classified into three main types:  

• Secundum ASD: This is the most common type of atrial septal defect, occurring in the middle part of the atrial septum due to an incomplete closure of the foramen ovale, a normal opening in the fetal heart that usually closes after birth, causing abnormal opening between the left and right atria.  

• Primum ASD: This type of atrial septal defect is in the lower part of the atrial septum, close to the atrioventricular valves. Atrioventricular valves are the “doors” between the upper chambers (atria) and the lower chambers (ventricles) of the heart.  This defect occurs when there is an incomplete fusion of the septum primum with the endocardial cushions during fetal development, resulting in an opening that allows blood to flow between the left and right atria.  

• Sinus Venosus ASD: This type of atrial septal defect is between the two upper chambers of the heart (atria) near the area where the veins enter the right atrium. This defect allows oxygen-rich blood from the left atrium to mix with oxygen-poor blood in the right atrium. It’s less common than other types of ASDs but can be more complex to treat.  

Causes 

The exact cause of atrial septal defect is often unknown however, genetic and environmental factors are believed to play significant roles.  

• Genetic predispositions, especially when there’s a family history of congenital heart defects, can be a leading factor in developing ASD. Also, certain genetic syndromes, such as Down syndrome, are associated with a higher risk of ASD.  

• Environmental factors, such as maternal infections, diabetes, or exposure to certain medications, drugs, or alcohol during pregnancy, can also be associated with a higher risk for the development of this condition.  

Symptoms 

 Many individuals with secundum ASD may remain asymptomatic, however, if the defect is large, it can cause symptoms such as s: 

• Shortness of breath 
• Fatigue 
• Swelling of the legs, feet, or abdomen 
• Heart palpitations 
• Stroke 

Diagnosis   

ASD is often diagnosed during a routine physical exam or when symptoms lead to further medical investigation. Diagnostic tests include: 

• Echocardiogram: This is an essential, non-invasive test that uses ultrasound waves to create in-depth images of the structure and function of the heart chambers and valves. This test can show the size and location of the ASD as well as any potential effects on the heart, like increased blood flow or enlarged heart chambers.  

• Electrocardiogram (ECG): This test records the electrical activity of the heart and can help identify abnormalities related to ASD such as signs of right atrial and ventricular enlargement or arrhythmias (irregular heartbeats)

• Chest X-ray: Chest X-rays provide a clear picture of the heart and lungs and can reveal complications related to Atrial Septal Defect (ASD such as an enlarged heart or changes in the lungs due to extra blood flow.  

• Cardiac MRI: Cardiac MRI provides highly detailed images of the heart’s structure, and can accurately determine the size, location, and severity of an ASD. MRI images can also provide comprehensive information about the defect and its impact on the heart and surrounding vessels. It is particularly useful for complex cases or when other imaging methods are inconclusive. 

• Cardiac catheterization: Cardiac catheterization is an advanced, minimally invasive diagnostic procedure carried out to evaluate ASD in detail when non-invasive tests, such as echocardiograms or MRIs, provide inconclusive results. It is particularly useful in complex cases where the exact size, location, and impact of the defect on heart function need to be precisely assessed. 

The procedure involves the inserting of a catheter into a blood vessel (in the groin or arm) and guided to the heart. This allows direct measurement of the pressures in the heart chambers and a precise assessment of the oxygen levels in different parts of the heart. Contrast dye can be injected through the catheter to enhance the visualization of the heart’s structures on X-ray images. 

This procedure is also considered when planning for catheter-based closure of the ASD. 

 Treatment Options  

Treatment for Atrial Septal Defect (ASD) is dependent on the size and type of the defect, the presence of symptoms, and the patient’s overall health. Small ASDs that do not display symptoms may only require regular monitoring since for some patients, can close on their own. For larger or symptomatic ASDs, treatment options include minimally invasive catheter-based procedures or traditional open-heart surgery.  

swMinimally invasive Closure 

Known as transcatheter closure, non-surgical closure is a minimally invasive method whereby a catheter is inserted into a vein, usually in the groin or arm and then guided to the heart. A specialized closure device is then passed through the catheter and placed over the ASD. Once the device is in position, it expands to seal the defect. With time, heart tissue grows around it, permanently closing the opening. 

This approach is often preferred for secundum ASDs. 

Surgical Closure 

Surgical treatment for Atrial Septal Defect (ASD) is performed mainly for larger or more complex defects or defects that are not suitable for transcatheter closure. This procedure involves open-heart surgery under general anesthesia whereby the heart is temporarily stopped, and a heart-lung machine takes over the circulation of blood and oxygen. The heart is accessed through an incision in the chest and the defect is repaired by sewing a patch made of synthetic material or from the patient’s own tissue over the hole or by stitching the edges of the defect together. After the repair, the heart is restarted, and the incision is closed. 

Recovery from open heart surgery requires several weeks of hospital stay for recovery and recuperation. While the procedure is more invasive than catheter-based methods, it is highly effective and provides a permanent solution for repairing the defect.