Q
My son has a "small" VSD (ventricular septal defect). What does having a Vmax greater than or equal to 4 m/sec mean? He is four years old and the hole has not changed at all in two years. One cardiologist has said that my son's hole is small and he would like to see it tiny, but that it does not require surgical intervention. My son also has a premature, irregular heartbeat that goes away when he exercises -- this was determined after he had a stress test last week. I know that the size of the hole is relative to the individual and that the heartbeat issue is supposedly unrelated, but how does a cardiologist determine when a hole is small enough to be left alone?
A
Vmax refers to the speed with which blood travels through the hole (VSD) in your son's heart wall. This number is determined when your son's cardiologist performs an echocardiogram (a type of ultrasound using sound waves) of your son's heart. Knowing the speed with which the blood travels through the hole helps the cardiologists determine the stress on the different chambers of the heart, which guides them in deciding how best to manage him.
There are several factors that a cardiologist considers when deciding whether to recommend surgery or a more conservative treatment for a child with a ventricular septal defect (VSD). The most important factor to consider is whether too much blood is passing through the hole. If too much blood is going from the left side of the heart to the right side, then surgery usually is necessary to close the hole. Other indications for surgery include slow growth in weight or height, frequent lung infections, or difficulty exercising. Even children without symptoms may also need to be operated on, usually between two and four years of age.
The cardiologist will likely follow your son with repeat echocardiograms to monitor the amount and speed of blood passing through the VSD over time. Your pediatrician will also be essential in monitoring your son's growth and development. If you notice any changes in your son's ability to exercise, you should speak with one of your son's doctors right away. The decision for surgery is one that must be addressed individually for each child.