When is ASD/VSD Closure Surgery Needed?

Introduction

Congenital heart defects affect thousands of newborns each year, with Atrial Septal Defect (ASD) and Ventricular Septal Defect (VSD) being among the most common. These conditions involve abnormal openings in the walls separating the heart’s chambers—ASD between the upper atria and VSD between the lower ventricles. While small defects may close naturally without any intervention, larger or persistent defects can result in serious complications if left untreated.

ASD and VSD can lead to excessive blood flow between heart chambers, causing the heart and lungs to work harder. This abnormal circulation may eventually result in pulmonary hypertension, heart failure, arrhythmias, and increased risk of stroke. Surgery or catheter-based closure is often the best solution in moderate to severe cases, but not every patient requires immediate intervention.

Understanding when is ASD/VSD closure surgery needed as it is crucial for timely treatment. Here are the primary situations in which closure is recommended by cardiologists and pediatric heart specialists.

When is ASD/VSD Closure Surgery Needed?

1. Large Defect with Significant Left-to-Right Shunt :- One of the most common indicators for closure surgery is the presence of a large septal defect that allows excessive blood to flow from the left side of the heart to the right side. This is known as a significant left-to-right shunt. The increased blood flow puts pressure on the right heart chambers and the pulmonary arteries, overloading the lungs and increasing the risk of pulmonary vascular disease over time. In such cases, the heart has to work harder to manage the volume overload, which may result in heart enlargement or weakening of the heart muscle. The goal of surgery is to stop this abnormal shunting and preserve heart and lung function before irreversible damage occurs. Closure surgery is typically recommended if the ratio of pulmonary to systemic blood flow (Qp:Qs) exceeds 1.5:1 or if there is evidence of right-sided chamber enlargement on echocardiography.

2. Symptoms of Congestive Heart Failure :- Some infants and children with large ASDs or VSDs may exhibit clear signs of congestive heart failure, especially during the first year of life. Symptoms may include rapid breathing, feeding difficulties, failure to thrive, excessive sweating, and recurrent respiratory infections. These signs occur due to the increased workload on the heart and lungs caused by the constant circulation of blood through the defect. When medical therapy such as diuretics or high-calorie nutrition support fails to improve the child’s condition, surgical intervention becomes necessary. Closing the defect relieves the pressure on the heart and allows the child’s overall health and growth to improve. In many cases, this surgery can be life-changing, significantly improving development and energy levels within weeks.

3. Pulmonary Hypertension :- If a large ASD or VSD is left untreated for too long, the excessive blood flow to the lungs may cause the blood vessels in the pulmonary circuit to thicken and narrow a condition known as pulmonary hypertension. Over time, this can progress into Eisenmenger syndrome, a dangerous and irreversible complication where blood starts to flow in the opposite direction (right-to-left), bypassing the lungs and leading to low oxygen levels in the body. Once Eisenmenger syndrome develops, surgery may no longer be a viable option. That’s why early detection and timely closure of the defect are essential in patients showing early signs of elevated pulmonary artery pressures. Preemptive surgery before these complications develop offers the best chance at long-term health and survival.

4. Presence of Recurrent Respiratory Infections :- Children with uncorrected ASD or VSD are often prone to frequent respiratory infections, including bronchitis and pneumonia. This is due to the continuous overload of blood being pushed into the lungs, creating a moist environment that encourages bacterial growth and inflammation. If respiratory infections are recurrent or severe despite appropriate treatment, it may be a sign that the underlying heart defect is affecting lung function. In such cases, surgical closure is considered not just to protect heart health but also to prevent long-term lung damage. Reducing pulmonary over-circulation through closure can significantly lower the frequency of respiratory illness and improve overall immunity and well-being in affected children.

5. Evidence of Heart Chamber Enlargement :- ASDs and VSDs can lead to abnormal stretching of the heart chambers, especially the right atrium and right ventricle in ASD, and the left heart chambers in large VSDs. Over time, this enlargement can weaken the heart’s pumping efficiency and lead to electrical conduction problems. Patients may develop atrial arrhythmias such as atrial fibrillation or flutter, even at a relatively young age. Closure of the defect helps reverse or prevent further chamber enlargement and reduces the risk of arrhythmias. In some adults with ASD, surgery is recommended primarily to reduce this risk. Additionally, patients who already have rhythm issues may benefit from having the defect closed to improve response to medications or rhythm control procedures.

6. Risk of Stroke or Paradoxical Embolism :- In rare cases, ASDs especially small or moderate-sized ones like a patent foramen ovale (PFO) can allow clots or air bubbles to travel from the venous system directly into arterial circulation, bypassing the lungs. This phenomenon is called a paradoxical embolism and can result in a stroke or transient ischemic attack (TIA). These events are often seen in young adults with no other risk factors for stroke, leading to the discovery of an underlying defect. If a stroke or embolic event is linked to the presence of an ASD or PFO, closure surgery is usually advised to prevent recurrence. The procedure is typically performed using a catheter-based device and has a high success rate in preventing future strokes in these patients.

7. Poor Exercise Tolerance :- Some patients may not show symptoms during early childhood, especially if the defect is moderate in size. However, as they grow older, they might experience fatigue, shortness of breath, or reduced ability to exercise. These signs indicate that the heart is under increasing strain due to the long-standing abnormal circulation. Surgical closure is beneficial in such cases to restore normal blood flow, improve oxygen delivery, and relieve symptoms. Early intervention is especially important in individuals who are active or wish to participate in sports or demanding physical activities.

Conclusion

Surgical or catheter-based closure of ASD/VSD is not universally required in all cases. Small, hemodynamically insignificant defects often resolve spontaneously, especially in infants and toddlers. However, in moderate to large defects, where the heart and lungs begin to show the strain of abnormal blood flow, closure becomes necessary to prevent long-term complications.

Timely diagnosis through echocardiography and consultation with a pediatric or adult congenital cardiologist is essential to determining the best treatment path. Modern surgical techniques and minimally invasive catheter-based closures have made ASD and VSD repair highly successful, with excellent outcomes and fast recovery in most patients.

For parents, caregivers, and adult patients, understanding the specific indications for closure can help facilitate informed discussions and ensure the right decisions are made at the right time.