The amount of blood flow from the left to right ventricle is dependent on the size of the hole and on the pressure difference between the ventricles. The higher the rate of flow, the more strain that is placed on the heart. The abnormal blood flow is responsible for the murmur that may be heard using a stethoscope.
Symptoms
Generally patients with a small VSD will exhibit no symptoms (they are asymptomatic) and the problem may only be found when a murmur is detected upon routine examination. Patients with a moderate VSD may breathe quickly, exhibit poor weight gain, be slow at feeding and prone to chest infections. This will be more pronounced where the hole is large.
Treatment
Patients with moderate or large holes will require treatment with diuretics such as Frusemide and Spironolactone to control fluid retention and to reduce the volume of blood in the circulation, thus making the workload on the heart easier. Drugs such as Captopril may be used in conjunction with these, to decrease the amount of left to right shunt.
Slow weight gain may lead to supplementation of a baby's milk with additives such as Calogen or Duocal, which increase the calorific intake. Severe feeding problems may necessitate feeding by way of a naso-gastric tube (through the nose and directly into the stomach), so that the baby does not use extra energy in obtaining nourishment.
Many VSD's will close spontaneously (naturally) or get much smaller, so it is normal practice to leave a patient with a small or moderate VSD and monitor their progress before deciding to operate. Indications for operation may be continued failure to thrive despite medication, or concern about high pressure in the pulmonary artery - pulmonary hypertension
In some children with large VSD's, it is apparent that spontaneous closure is very unlikely due to the size and placement of the hole, and surgery will be recommended without delaying to see if the hole diminishes usually at 3-6 months of age. If closure is unlikely, nothing is to be gained by waiting, and the aim is to limit damage to the lungs.
Follow Up Advice
Most patients with a cardiac defect will require antibiotic cover during any dental treatment to prevent bacteria entering the blood stream from where they can reach the heart causing bacterial endocarditis (infection of the heart lining), which can be very serious. If complete surgical or spontaneous closure occurs, the patient's unit may advise that antibiotic cover can be discontinued one year after closure, but it is important that you check the advice with regard to the patient as an individual.
