A partial atrioventricular septal defect (AVSD) is a type of heart defect that is present at birth (congenital). Normally, the four heart chambers are separated by walls (septum) to keep oxygen rich and oxygen poor blood separate. The blood flow is controlled by valves. In partial AVSD, the hole is located in the wall between the top two chambers of the heart (atrium). The mitral valve (between the left atrium and ventricle) may leak. The oxygen rich and poor blood mixes due to these defects which causes the heart to send too much blood to the lungs. The overworked heart enlarges and the blood pressure in the lungs becomes too high. AVSD may eventually lead to heart failure, though this is less common in partial compared to complete AVSD.
Common symptoms may include difficulty breathing, abnormal heartbeats (arrhythmia), and poor blood circulation, which can cause bluish lips and skin and swelling in the legs (edema). Children with AVSD may also have poor appetite and tire easily. Partial AVSD is usually diagnosed during the first year of life. The causes of AVSDs are believed to be a combination of genetics and environment. Babies with Down syndrome are at an increased risk to develop this condition. Other risk factors include drinking alcohol during pregnancy or poorly controlled maternal diabetes.
Doctors may hear a swishing sound in the heartbeat (a murmur) when listening with a stethoscope. Tests used to confirm an AVSD may include a chest X-ray, electrocardiogram (EKG) (tests the electrical impulses), echocardiogram (using sound waves to create a picture), or cardiac MRI.
Smaller defects may close on their own, but the most common treatment is surgical repair. If your baby or child has been diagnosed with an AVSD, talk to their pediatric cardiologist about the most current treatment options. Support organizations and genetic counselors are also a good source of information and can help connect you with others affected by AVSD.