children s health issues
Total Anomalous Pulmonary Venous Return (TAPVR)
Introduction
In total anomalous pulmonary venous return, the pulmonary veins, blood vessels that normally carry oxygenated blood from the lungs to the left side of the heart, connect instead to the right side of the heart. This blood then flows to the left heart through a hole in the wall separating the left and right heart chambers. Children with more mild forms of TAPVR may only have mild feeding and breathing problems in infancy. Children with more severe TAPVR may have bluish discoloration of the skin (cyanosis), shortness of breath, and fatigue. Children with the most severe forms of this defect may develop severe respiratory distress and cyanosis shortly after birth. Echocardiography is needed for diagnosis. The defect is treated with surgical repair. (See also Overview of Heart Defects .) Total anomalous pulmonary venous return (TAPVR) accounts for 1 to 2% of birth defects of the heart. Normally, the pulmonary veins return blood that has picked up oxygen in the lungs to the left atrium. This oxygenated blood then flows from the left atrium into the left ventricle, where it is pumped to the body. (See also Normal Fetal Circulation .) In infants born with TAPVR, the pulmonary veins do not connect normally to the left atrium and connect instead by an abnormal pathway eventually leading to the right atrium. So the right atrium, which usually receives only deoxygenated blood from the body to be pumped to the lungs, receives a mix of oxygenated and deoxygenated blood. The additional blood return causes an increased workload and enlargement of the right side of the heart. Even more importantly, blood flow from the pulmonary veins makes its way to the right atrium through various pathways, going up above the heart, down below the heart, or around the back wall of the heart. These pathways can be narrow or blocked, causing blood to back up in the lungs and pressure to build up in the lungs, preventing their normal function. Blood only flows to the left side of the heart through a hole between the right and left atria (a patent foramen ovale or The pulmonary veins do not connect to the left atrium; instead, the entire pulmonary venous return enters systemic venous circulation through various connections (in this case the connecting vein is supracardiac or above the heart). Connecting veins can also be below the heart (infracardiac) or behind the heart. Systemic blood flow depends on right-to-left atrial shunting. AO=aorta; IVC=inferior vena cava; LA=left atrium; LV=left ventricle; PA=pulmonary artery; PV=pulmonary veins; RA=right atrium; RV=right ventricle; SVC=superior vena cava. 