|Anterior (frontal) view of the opened heart. White arrows indicate normal blood flow. (Tricuspid valve labeled at bottom left.)|
Tricuspid atresia is a form of congenital heart disease whereby there is a complete absence of the tricuspid valve. Therefore, there is an absence of right atrioventricular connection. This leads to a hypoplastic (undersized) or absent right ventricle. This defect is contracted during prenatal development, when the heart does not finish developing. It causes the heart to be unable to properly oxygenate the rest of the blood in the body. Because of this, the body does not have enough oxygen to live, so other defects must occur to maintain blood flow. Because of the lack of an A-V connection, an atrial septal defect (ASD) must be present to fill the left ventricle with blood. Also, since there is a lack of a right ventricle there must be a way to pump blood into the pulmonary arteries, and this is accomplished by a ventricular septal defect (VSD). The causes of Tricupsid atresia are unknown.
An atrial septal defect (ASD) and a ventricular septal defect (VSD) must both be present to maintain blood flow-from the right atrium, the blood must flow through the ASD to the left atrium to the left ventricle and through the VSD to the right ventricle to allow access to the lungs
- progressive cyanosis
- poor feeding
- tachypnea over the first 2 weeks of life
- holosystolic murmur due to the VSD
- left axis deviation on electrocardiography and left ventricular hypertrophy (since it must pump blood to both the pulmonary and systemic systems)
- normal heart size
CXR : decreased pulmonary blood flow and oligemic lung field
ECG : left axis deviation
- PGE1 to maintain patent ductus arteriosus
- modified Blalock-Taussig shunt to maintain pulmonary blood flow by placing a Gore-Tex conduit between the subclavian artery and the pulmonary artery.
- where too much flow to the lungs is present, a pulmonary band may be placed in a first operation
- cavopulmonary anastomosis (hemi-Fontan or bidirectional Glenn) to provide stable pulmonary flow
- Fontan procedure to redirect inferior vena cava and hepatic vein flow into the pulmonary circulation