Ventricular Septal Defect (VSD): Symptoms, Diagnosis, and Closure Treatment

What Is a Ventricular Septal Defect?

A ventricular septal defect (VSD) is a congenital opening in the wall separating the right and left ventricles of the heart.

It is one of the congenital conditions commonly described as a "hole in the heart."

Normally, the two ventricles are separated by an intact septum.

In patients with VSD, blood usually flows from the higher-pressure left ventricle into the right ventricle.

This may increase blood flow to the lungs.

Small VSDs may have little effect on cardiac function, while larger defects can lead to cardiac chamber enlargement, pulmonary hypertension, and heart failure.

Not every VSD requires closure. Treatment decisions depend on the hemodynamic significance of the defect and pulmonary vascular resistance, not simply its diameter.

What Are the Types of VSD?

1. Perimembranous VSD

This is the most common type of VSD.

It is located near the membranous portion of the ventricular septum.

It may be close to the aortic and tricuspid valves.

Some perimembranous defects become smaller or close spontaneously.

2. Muscular VSD

Muscular VSDs occur within the muscular portion of the ventricular septum.

They may be single or multiple.

Small muscular defects frequently close spontaneously during childhood.

3. Outlet (Subarterial) VSD

Outlet VSDs are located near the aortic and pulmonary valves.

They may cause prolapse of an aortic valve cusp and lead to aortic regurgitation.

Therefore, careful follow-up is important even when the defect is relatively small.

4. Inlet VSD

Inlet VSDs are located near the atrioventricular valves.

They may be associated with atrioventricular septal defects.

What Are the Symptoms of VSD?

Symptoms depend on the size of the defect, pulmonary blood flow, and pulmonary vascular pressure.

Small VSD

Small defects are often asymptomatic.

They may be discovered when a heart murmur is detected during a routine examination.

Large VSD

In infants, symptoms may include:

Rapid breathing
Difficulty feeding
Sweating during feeding
Poor weight gain
Recurrent respiratory infections
Signs of heart failure

Adults with hemodynamically significant VSD may experience:

Shortness of breath during exertion
Fatigue
Palpitations
Reduced exercise tolerance
Symptoms of heart failure

What Causes VSD?

VSD develops when the ventricular septum does not form completely during fetal heart development.

In most patients, the exact cause is unknown.

Some defects are associated with genetic syndromes or other congenital heart abnormalities.

A ventricular septal rupture may also occur after myocardial infarction, but this is a distinct, life-threatening acquired condition requiring emergency treatment.

How Does VSD Affect the Heart?

A significant VSD increases blood flow through the pulmonary circulation.

Over time, this may lead to:

Left atrial and left ventricular enlargement
Heart failure
Pulmonary hypertension
Aortic regurgitation
Infective endocarditis

Large, long-standing shunts may cause irreversible changes in the pulmonary vasculature.

If pulmonary vascular resistance becomes severely elevated, the direction of blood flow may reverse.

This condition is known as Eisenmenger syndrome.

It may cause low blood oxygen levels and cyanosis.

VSD closure may be dangerous in patients with advanced, irreversible pulmonary vascular disease.

How Is VSD Diagnosed?

1. Echocardiography

Echocardiography is the primary diagnostic method for VSD.

It evaluates:

Defect location
Defect size
Direction of blood flow
Hemodynamic significance
Cardiac chamber dimensions
Ventricular function
Estimated pulmonary artery pressure
Associated valve abnormalities

Color Doppler imaging helps visualize blood flow through the defect.

2. Transesophageal Echocardiography (TEE)

TEE may provide additional anatomical information, particularly when intervention is being planned.

3. Cardiac MRI

Cardiac MRI can help quantify shunt flow, cardiac chamber volumes, and ventricular function.

4. Cardiac CT

CT may be useful for evaluating complex anatomy in selected patients.

5. Right Heart Catheterization

Right heart catheterization may be required when pulmonary hypertension is suspected, particularly to measure pulmonary vascular resistance and assess the safety of closure.

Can a VSD Close Spontaneously?

Yes.

Many small muscular VSDs close spontaneously during childhood.

Some perimembranous VSDs may also become smaller or close over time.

Large defects are less likely to close spontaneously.

Spontaneous closure is generally less common once a defect persists into adulthood.

When Should a VSD Be Closed?

Closure decisions depend on several factors:

Left ventricular volume overload
Hemodynamically significant left-to-right shunting
Pulmonary artery pressure
Pulmonary vascular resistance
Symptoms
Development of aortic regurgitation
Previous infective endocarditis
Defect anatomy

A pulmonary-to-systemic flow ratio (Qp/Qs) of 1.5 or greater may support the presence of a significant shunt in appropriate circumstances.

However, this measurement alone is insufficient to determine whether closure is indicated.

Patients with pulmonary hypertension require particularly careful evaluation by a team experienced in adult congenital heart disease.

How Is VSD Closed?

There are two main treatment approaches.

1. Surgical VSD Closure

Surgical closure is a well-established treatment and remains the standard approach for many types of VSD.

The opening is closed using direct sutures or a surgical patch.

Surgery is particularly relevant for large defects, associated valve abnormalities, or anatomy unsuitable for transcatheter treatment.

2. Transcatheter VSD Closure

Selected VSDs can be closed using a catheter-based procedure without open-heart surgery.

A specially designed closure device is delivered through blood vessels and positioned across the defect.

Transcatheter closure may be suitable for selected muscular VSDs and certain other anatomically appropriate defects.

Not every VSD is suitable for device closure.

How Is Transcatheter VSD Closure Performed?

The exact technique depends on defect anatomy.

In general:

Catheters are introduced through blood vessels in the groin.
The defect is assessed using echocardiography and fluoroscopy.
An appropriate closure device is selected.
The device is positioned across the defect.
Its stability and relationship with nearby valves are evaluated.
The device is released after satisfactory positioning is confirmed.

Careful attention is required to avoid injury to the aortic and tricuspid valves and the cardiac conduction system.

What Are the Risks of VSD Closure?

Risks vary according to patient age, defect anatomy, and associated conditions.

Potential complications of transcatheter closure include:

Vascular access bleeding
Device displacement
Residual shunting
Aortic or tricuspid regurgitation
Arrhythmias and conduction abnormalities
Atrioventricular block
Rare device-related thrombosis or other serious complications

Complete atrioventricular block is an important potential complication of device closure in certain VSD types.

Does the Heart Recover After VSD Closure?

Successful closure can reduce cardiac volume overload.

Enlarged cardiac chambers may decrease in size, and cardiac function may improve over time.

However, longstanding pulmonary hypertension or irreversible pulmonary vascular disease may limit recovery.

Is Follow-Up Necessary After VSD Closure?

Yes.

Follow-up evaluates:

Residual shunting
Cardiac chamber dimensions
Ventricular function
Aortic regurgitation
Pulmonary artery pressure
Cardiac rhythm and conduction

The frequency of follow-up depends on the type of defect, treatment performed, and any residual abnormalities.

Is There a Risk of Infective Endocarditis?

Patients with VSD may have an increased risk of infective endocarditis.

Good oral hygiene and regular dental care are important.

However, antibiotic prophylaxis is not required before every dental procedure in all patients with VSD.

Preventive antibiotics are reserved for specific high-risk circumstances according to current guidelines.

What Is the Difference Between VSD and ASD?

ASD is an opening between the two atria.

VSD is an opening between the two ventricles.

ASD commonly causes right heart volume overload.

A significant left-to-right VSD more commonly produces left heart volume overload.

The hemodynamic effects of VSD depend on defect size and pulmonary vascular resistance.

Therefore, treatment and closure criteria differ between ASD and VSD.

Can Patients with VSD Live a Normal Life?

Many patients with small, hemodynamically insignificant VSDs can lead normal lives.

Long-term outcomes are generally favorable after successful closure when no significant residual disease remains.

However, some patients require lifelong cardiology follow-up.

When Should You Consult a Cardiologist?

A newly detected heart murmur, unexplained shortness of breath, fatigue, palpitations, or suspected congenital heart disease should prompt cardiac evaluation.

Adults diagnosed with VSD may benefit from assessment at a center experienced in adult congenital heart disease.

Sudden severe breathlessness, fainting, chest pain, or marked cyanosis requires urgent medical attention.

Assoc. Prof. Sezen Bağlan Uzunget, MD
Cardiologist

This content is provided for general educational purposes. VSD diagnosis, follow-up, and closure decisions should be individualized according to defect anatomy, hemodynamic significance, and pulmonary vascular resistance.