AV canal   

• Most common form of CHD in Down Syndrome (40%)
• Incomplete = primum ASD w/clefted AV valves
• Complete = contiguous ASD/VSD with single, incompetent AV valve
• Present w/ FTT, recurrent resp. infxns, CHF
• Holosystolic murmur @ LLSB, +/-mid-diastolic rumble

Pathophysiology

• Left to right shunts at the atrial and ventricular levels
• AV valve regurgitation
• Tendency for children with Down Syndrome to have prolonged persistent fetal circulation may result in bidirectional shunting and cyanosis

EKG (EKG stuff)

• Superior axis
• RVH

CXR

• Cardiomegaly
• Increased pulmonary vascular markings
• Prominent MPA

Management

• All require corrective surgery
• Some degree of AV valve regurgitation common post op
• Lifelong SBE prophylaxis

CHLA Board Review 2005
Park MK. Pediatric Cardiology for Practictioners, 3rded. St. Louis,
 Mosby, 1996.