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Posted by Dr. Monica Wonnacott | January 18, 2017

VSD: A Common Congenital Heart Defect

A VSD, or ventricular septal defect, is a fancy medical term to describe a hole in the heart that isn’t supposed to be there. VSDs are relatively common and are one of the top 3 causes of heart murmurs that I see in my clinic. While VSDs can be part of other/bigger heart defects, they happen as isolated defects as well. I’m going to address only the isolated problems. Isolated VSDs make up about 20% of all congenital heart defects (which is a huge percentage considering all the possible heart problems). VSDs happen in 2-7% of all live births.

Where exactly is the hole in the heart?

As you probably already know, the heart is a muscle about the size of your fist. It has 4 chambers or compartments. Think of the heart like a box. The upper 2 boxes are “atria” and the lower 2 boxes are “ventricles.” The blood is supposed to flow between the atria and ventricles (through a little one-way valve), essentially up and down in the box analogy. The 2 compartments of atria have a big wall of muscle that separates them and prevents them from sharing blood. Again using the box analogy, it prevents side-to-side flow. The ventricles have a similar wall of muscles between their 2 chambers, preventing the ventricles from communicating. When there is a hole or defect in the wall separating the two ventricles (the lower half of the boxes in the heart), the ventricles can have blood flow back and forth. When the blood goes from ventricle to ventricle (a path it’s not supposed to go), the blood that is flowing the wrong way will usually make a sound or murmur.

Is it something to worry about?

Generally the answer is no. Many VSDs are relatively small and will close up on their own. The VSDs that cause worry are the ones that cause other associated symptoms (e.g., feeling tired, sweating-especially during feeds, poor weight gain, or fast breathing). These other symptoms indicate complications (e.g., congestive heart failure)

How are VSDs diagnosed?

Most of the time, a parent will be made aware of the problem when a pediatrician listens with a stethoscope to a child’s heart and discovers a murmur. The definitive diagnosis is then made by a test called an echocardiogram, or echo (which is essentially an ultrasound of the heart).

How it is treated?

Small VSDs are usually treated with “watchful waiting.” This is medical lingo for “do nothing, but keep an eye on it to make sure things don’t get worse.” Often, small VSDs will close on their own, so nothing needs to be done. Sometimes larger VSDs can lead to congestive heart failure (CHF) and will require medications to manage that. Severe cases (that involve the pulmonary blood flow) will need surgery.

Should I see a cardiologist (heart specialist)?

Simple VSDs that resolve on their own, do not always require the expertise of a specialist. However, if there is anything concerning sounding about the murmur or history that is concerning, it is prudent to seek the care of specialist. Your pediatrician will help guide you on if/when to see a cardiologist.

Will my child need surgery for it?

Most cases of children with VSDs do not need surgery. Only children who have moderate-to-large defects that are causing increased blood flow to the lungs usually require surgery.

Did I do something to cause my baby to have this?

The last thing a mother needs is to hear is that she is responsible for her baby’s birth defect. Mothers are already plagued with enough guilt. However, the truth is, some maternal conditions increase the risk of having a child with a heart defect. Maternal diabetes is a well-recognized risk factor for congenital heart defects. Maternal alcohol consumption has also been linked to babies that have VSDs (specifically, a certain subtype called muscular VSDs).

Are VSDs genetic?

The short answer is yes, sort of. The genetic transmission isn’t a direct line like some conditions, but having a family history of previous congenital heart defects (in either parents or siblings), greatly increases the risk (about 3 times) of subsequent children having congenital heart defects. There are also some genetic conditions that are associated with heart defects (e.g., Down syndrome).