Atrial septal defect (ASD)

Main types

1. Ostium secundum ASD: Most common. Located at the fossa ovalis in the central atrial septum. Often suitable for transcatheter device closure.
2. Ostium primum ASD: Low in the septum and commonly associated with atrioventricular valve abnormalities. Usually requires surgery.
3. Sinus venosus ASD: Near the superior or inferior vena cava; may occur with partial anomalous pulmonary venous return. Usually surgical.
4. Coronary sinus defect: Rare.

Symptoms and signs

• Breathlessness on exertion, reduced exercise tolerance, fatigue
• Palpitations or atrial fibrillation/flutter
• Frequent respiratory infections in children
• Fixed wide splitting of the second heart sound, sometimes with a systolic flow murmur
• Right-heart enlargement and pulmonary hypertension in untreated significant defects

Diagnosis

• Transthoracic echocardiography with color Doppler is the main test.
• Transesophageal echocardiography, cardiac MRI, or CT may define anatomy and associated abnormal pulmonary veins.
• ECG may show right-sided conduction or chamber changes.
• Cardiac catheterization is used selectively, particularly when pulmonary hypertension or closure suitability is uncertain.

Treatment

• Right atrial/right ventricular enlargement from volume overload, and/or
• A significant shunt, commonly Qp:Qs >1.5:1.

Follow-up

Interpretation of the echocardiogram

Bottom line

Most likely treatment option: transcatheter device closure

• No chest incision or sternotomy
• Usually 1 to 2 nights in hospital
• Faster recovery than surgery
• High closure success when the rims and anatomy are suitable

When surgery is used

• The defect has inadequate rims for a device
• The ASD is too large or has unusual anatomy
• It is actually a sinus venosus or primum defect rather than a secundum ASD
• There is associated anomalous pulmonary venous drainage or another cardiac condition needing repair

Tests to arrange before choosing treatment

1. TEE, preferably 3D TEE
   To confirm ASD type, exact diameter, number of defects, and all device-supporting rims.
2. ECG and rhythm assessment
   To check for atrial arrhythmias, particularly atrial fibrillation or flutter.
3. Assessment of pulmonary pressures and shunt size
   The report does not give pulmonary artery pressure, estimated right-ventricular systolic pressure, Qp:Qs ratio, or pulmonary vascular resistance.
4. Cardiac catheterization, if pulmonary hypertension is suspected or echo measurements are uncertain
   This measures the shunt and pulmonary vascular resistance directly. Closure should be avoided if there is severe fixed pulmonary vascular disease. The ACC adult ASD review notes that ASD closure should be avoided when pulmonary vascular resistance remains high despite pulmonary-hypertension treatment.
5. Cardiac MRI or CT, sometimes
   Especially if there is concern for anomalous pulmonary veins or if echo images are incomplete.

Medicines

• Diuretics for fluid retention or breathlessness due to heart failure
• Medicines for atrial fibrillation/flutter if present
• Anticoagulation only if an arrhythmia, clot risk, or another indication is confirmed

After closure

Practical recommendation

1. What is a TEE?

What TEE checks in your case

• The exact size and shape of the hole
• Whether there is one ASD or more than one
• The tissue margins around it, called rims. These are needed to anchor a closure device safely.
• Distance from the aorta, vena cavae, mitral valve, and pulmonary veins
• Direction and size of the shunt
• Right-heart enlargement and estimated lung pressures
• Any unexpected abnormal pulmonary vein drainage or clot

What happens during a TEE

1. You usually fast for about 6 hours beforehand. The hospital will give exact instructions.
2. An IV line is placed, and the throat is numbed with spray.
3. Sedation is usually given, so most people are sleepy and recall little.
4. A mouth guard is placed and the probe is gently passed into the esophagus.
5. Images are taken for about 15 to 30 minutes.
6. You are observed until the sedation wears off, then need someone else to take you home. Avoid driving that day.

TEE risks

2. What is ASD device closure?

Steps in the procedure

1. Preparation and anesthesia
   Usually general anesthesia or deep sedation is used. You do not feel the procedure.
2. Groin-vein access
   The cardiologist makes a small puncture in the femoral vein, usually in the right groin.
3. Catheter goes to the heart
   A thin tube is moved through the vein into the right atrium and across the ASD. No chest incision is needed.
4. Measurements and imaging
   TEE, or sometimes intracardiac echocardiography, helps measure the ASD and confirm the rim anatomy. In some patients, balloon sizing is performed.
5. Device placement
   The left-sided disc is opened in the left atrium, gently pulled against the septum, then the right-sided disc is opened in the right atrium.
6. Safety check before release
   The team confirms that the device is stable, does not interfere with valves or nearby vessels, and that there is little or no residual shunt.
7. Release and recovery
   The device is detached from the delivery cable. The groin puncture is compressed or closed. The procedure often takes about 1 to 2 hours, but total time in the procedure room may be longer.

Is it likely to be an option for this report?

Benefits expected from closure

• Stops the abnormal left-to-right shunt
• Reduces excess blood flow to the lungs
• Allows the enlarged right atrium and right ventricle to remodel over time
• May improve breathlessness, fatigue, or exercise tolerance if present
• Helps prevent later complications such as atrial arrhythmias, right-heart failure, and pulmonary vascular disease

Risks of device closure

• Bruising or bleeding at the groin
• Temporary palpitations or arrhythmias
• A small residual leak around the device
• Device movement or embolization, rarely requiring catheter retrieval or surgery
• Clot formation on the device
• Pericardial effusion or cardiac erosion, very rare
• Allergy or kidney issues related to contrast, if contrast is used
• Need for surgery if device deployment is not safe or successful

After the procedure

• Observation overnight, occasionally discharge the same day depending on the center and recovery
• Echocardiogram before discharge or at early follow-up
• Antiplatelet medication, often aspirin with or without another agent for a limited time. Your cardiologist must choose the medicines and duration for you.
• Avoid strenuous exercise and heavy lifting for roughly a week, subject to the treating team's advice.
• Follow-up echocardiography to confirm device position, no significant leak, and improvement in right-heart size.

Questions to ask at the TEE/consultation

1. Is this definitely a secundum ASD?
2. What are the ASD dimensions and all rim measurements?
3. Are the rims adequate for device closure?
4. What are the pulmonary artery pressure and Qp:Qs shunt ratio?
5. Do I need cardiac catheterization before closure?
6. Which device is proposed, and why?
7. What antiplatelet treatment and follow-up schedule will I need?