Ventricular Septal Defect (VSD)
Ventricular septal defect is one of the most common congenital heart defects and involves a hole in the middle wall (septum) between the right and left ventricle. This type of defect is also referred as a “hole in the heart.” In a normal heart, all of the blood that is pumped out from the left ventricle goes into the aorta. In patients with a VSD, when the heart beats, part of the blood in the left ventricle will flow back to the right ventricle through the hole in the septum. The blood flowing through the hole creates a whooshing noise known as a pathologic heart murmur. In this condition, the heart works harder as it must pump not only the blood coming normally to the heart from the rest of the body but, in addition, it must pump the extra amount of blood flowing through the VSD. There are different types of ventricular septal defects based on the location within the ventricular septum. In addition, they can vary in size from tiny to large. Sometimes, a VSD can also be present as part of more complex types of congenital heart defects.
Causes of VSD:
Most ventricular septal defects are congenital, which means they occur during fetal heart development and are present at birth. In exceptionally rare cases, it may be traumatic and created by a severe blow to the anterior chest wall such as in a motor vehicle accident.
In some cases, a VSD may have a genetic basis. There can be chromosomal abnormalities such as Down syndrome, which has a higher incidence of VSD. In addition, there may be syndromes such as Alagille, Cornelia de Lange, Holt-Oram, Smith-Lemli-Opitz, Simpson-Golabi, and other syndromes with a higher incidence of VSD. In addition, they may be associated with some type of illness during the pregnancy.
For the vast majority of children with a VSD, however, there is no evident cause as to why a VSD is present.
Patients with a small to moderate VSD are usually asymptomatic. Patients with a larger VSD may become symptomatic during the first few months of life, or earlier, if associated congenital heart defects are present such as coarctation of the aorta and aortic stenosis.
A loud murmur is usually indicative of a small VSD and, less commonly, a larger VSD with mixing of blood through the hole. On the other hand, a patient with a large VSD may present with no murmur at all during the first few days of life, and a heart murmur may appear a few days or weeks later as the pressures in the lungs normalize. A child with Down syndrome or pulmonary hypertension may have a VSD without any audible murmur. That is why all patients with Down syndrome should undergo cardiovascular screening with an echocardiogram.
A murmur may become louder as the VSD becomes progressively smaller. The typical heart murmur is a squeaky or harsh systolic murmur, which may not always be present.
Children with moderate-large VSD may develop these symptoms:
Rapid and difficult breathing
Trouble gaining weight
Frequent lung infections
Swelling around the eyes, back of hands, or feet
Fatigue or tiredness
Shortness of breath during exercise
In about half of the children born with a VSD, the hole is so small that it will close on its own in a few months or several years. Smaller and muscular ventricular septal defects have a much higher incidence of spontaneous closure.
Diagnosis and Cardiovascular Tests:
Most patients with a VSD will have a typical heart murmur. The child is usually referred to us for a second opinion and confirmation of the clinical diagnosis. A cardiovascular evaluation usually includes an electrocardiogram and echocardiogram. The echocardiogram will confirm the diagnosis and determine the size and location of the ventricular septal defect. In addition, it may show multiple ventricular septal defects. An echocardiogram is also very helpful in determining the heart size and function. It will also help rule out any other heart defects that may coexist with a VSD. A chest x-ray may be requested in larger ventricular septal defects. A cardiac catheterization is rarely necessary.
Patients with smaller ventricular septal defects usually do not require any type of treatment. The patients are required to keep optimal dental hygiene and semiannual dental appointments in trying to avoid a serious heart infection (endocarditis). Ventricular septal defects tend to get smaller or will close completely without need of any treatment. A small VSD causes no symptoms and may simply need to visit us regularly to make sure that there are no problems.
If there is a medium to large VSD, medical treatment may be necessary, especially if the heart is enlarged or if the patient is developing symptoms. Medications may include diuretics (water pill). Other medications may improve the heart’s contractility or it may help reduce the excessive workload.
Patients with a larger VSD may end up requiring surgery. In most cases, the surgery may be delayed for one to four years. A few people have surgery for a VSD during late childhood or adolescence. Timing of the surgery depends on the location of the VSD and if there are multiple holes. Patients with failure to thrive, heart failure, and frequent lung infections may benefit from an earlier surgery. Patients that may be developing high pressures in the lung vessels should be followed closely and operated on at an earlier age.
Heart surgery involves making a cut in the mid-chest and heart wall. In an atrial approach, the surgeon may have to go through the tricuspid valve so that he or she can stitch the hole closed. Patients with a larger VSD may need a patch sutured over the hole. Eventually, the tissue of the heart grows over the patch or stitches and, by six months after the surgery, the hole may be completely covered with the heart’s inner lining. A small patch leak may persist for months or years after the surgery. At the time of the surgery, the surgeon may take care of any associated heart defect such as an obstruction inside the heart or at one of the heart valves.
The surgery for VSD is considered low-risk. Potential complications may include infection, bleeding, leaky heart valve, residual VSD, heart failure, reaction to general anesthesia, pneumonia, vocal cord injury, prolonged ventilation, and heart block requiring implantation of a pacemaker.
Patients with a VSD are at greater risk of developing endocarditis than the normal population. The best way to prevent the heart from a serious infection is optimal dental hygiene, which includes brushing two to three times per day, flossing, and semi-annual dental cleanings. In general, it is no longer recommended for patients with a simple VSD to take antibiotics prior to dental visits, except for the first six months after surgery if there is a residual VSD patch leakage. Parents should consult with Dr. Villafañe and see if their child needs SBE prophylaxis.
Patients with a small VSD that underwent a successful surgery may lead a normal life and have no restrictions. A pediatric cardiologist should follow them periodically in order to monitor heart size and function as well as to look for any potential complications.
Patients with a larger VSD that goes untreated may develop heart failure, pulmonary hypertension (high pressures in the lung vessels), aortic insufficiency, frequent lung infections, and poor growth and weight gain. These patients are at risk of developing irreversible lung damage, Eisenmenger complex, which carries a bad prognosis. Patients with Down syndrome need better surveillance by their doctor as they are at a higher risk of developing pulmonary hypertension. These patients may also develop irregular heartbeats.
Athletes with a small to moderate VSD and normal pulmonary artery pressures can participate in all competitive sports. Athletes with a larger VSD are candidates for surgical repair, and full participation in all competitive sports would normally occur six months after successful VSD closure. Athletes with a residual hole and heart enlargement or decreased ventricular function by echocardiogram may require further testing. This may include patients with pulmonary hypertension, and symptomatic arrhythmias. Dr Villafañe should be consulted to see what type of further testing or sport limitations would be necessary.
These days, having a small to moderate VSD is usually nothing to worry about. Dr. Villafañe is very familiar with this common heart defect and understands how to best take care of it. Virtually all children with a VSD can enjoy the same activities as their peers and live long, healthy, active lives. Those patients with a history of heart failure usually recover after surgery or if the VSD gets smaller and smaller.