Complete atrioventricular canal defect is present at birth and occurs when there is a hole between the chambers of the heart as well as issues with the valves that regulate blood flow within the heart. This defect allows extra blood to be pumped through the lungs, which may cause lung problems or the heart to be overloaded and tire out. Symptoms usually occur early in life and may include: difficulty breathing, lack of appetite, poor weight gain, discoloration of the lips and skin, fatigue, wheezing, swelling in the legs and feet, sudden weight gain (from fluid retention), decreased alertness, and irregular or rapid heartbeat. A doctor can diagnose you with this condition by using a physical exam, an echocardiogram, or cardiac catheterization. Treatment includes surgery to close the hole and reconstruct the affected heart valves. If left untreated, this condition may lead to heart failure or high blood pressure in the lungs.