Disease Information for Incomplete AV/cushion defect

Clinical Manifestations
Signs & Symptoms
Cardiac auscultation/abnormal
Cardiac Symptoms/Signs
Disease Progression
Course/Chronic disorder
Course/Chronic only
Demographics & Risk Factors
Population Group
Population/Pediatrics population
Sex & Age Groups
Population/Child-Infant Only
Diagnostic Test Results
EKG/Left-axis deviation (ECG)
Echo/Echocardiogram Abnormal
Associated Diseases & Rule outs
Rule Outs
Atrioventricular (AV) canal/congenital defect
Associated Disease & Complications
Ventricular septal defect
Disease Mechanism & Classification
CLASS/Cardiovascular (category)
CLASS/Heart disorder (ex)
PROCESS/Congenital/developmental (category)
PROCESS/Anomalies/Deformities/Malformations (EX)

Atrioventricular Septal Defect


Atrioventricular Canal Defects

Common Atrioventricular Canal (CAVC) Defect

Endocardial Cushion Defects

Disorder Subdivisions

Complete Atrioventricular Septal Defect

Incomplete Atrioventricular Septal Defect

Partial Atrioventricular Septal Defect

Transitional Atrioventricular Septal Defect

General Discussion

Atrioventricular septal defect (ASVD) is a general term for a group of rare heart defects that are present at birth (congenital). Infants with ASVDs have improperly developed atrial and ventricular septa and adjoining valves.

The normal heart has four chambers. The two upper chambers, known as atria, are separated from each other by a fibrous partition called the atrial septum. The two lower chambers, known as ventricles, are separated from each other by the ventricular septum. Valves (e.g., mitral and tricuspid) connect the atria (left and right) to their respective ventricles. The valves allow for blood to be pumped through the chambers. Blood travels from the right ventricle through the pulmonary artery to the lungs where it receives oxygen. The blood returns to the heart through pulmonary veins and enters the left ventricle. The left ventricle sends the now oxygen-filled blood into the main artery of the body (aorta). The aorta sends the blood throughout the body.

The parts of the heart described above are formed from an embryonic structure called the endocardial cushions. In individuals with ASVD there is some combination of malformation of these parts of the heart. They may include a hole in the atrial septum, a hole in the ventricular septum, and/or abnormalities of the mitral and triscupid valves. ASVD may be classified as one of three forms: an incomplete (or partial) ASVD (atrial septal defect primum); a transitional form (atrial septal defect and small ventricular septal defect); or a more severe or complete form (large atrial and ventricular defects).

The symptoms of ASVD vary greatly and depend on the severity of the malformations (e.g., valve leakage between ventricles and ventricular size). About half the cases of ASVD occur in children with Down syndrome.[NORD 2005]


External Links Related to Incomplete AV/cushion defect
PubMed (National Library of Medicine)
NGC (National Guideline Clearinghouse)
Medscape (eMedicine)
Harrison's Online (accessmedicine)
NEJM (The New England Journal of Medicine)