Tetralogy of Fallot with Absent Pulmonary Valve
Bailey Cox, RCCS
Tetralogy of Fallot with absent pulmonary valve is a rare congenital heart defect which includes all the findings of Tetralogy of Fallot with an underdeveloped or total absence of the pulmonary valve tissue. It is reported in about 3% of all Tetralogy of Fallot cases. The pulmonary valve annulus is usually narrowed and the lack of pulmonary valve tissue generates severe pulmonary regurgitation. The to-and-fro blood flow across the right ventricular outflow tract produces significant dilatation of the right ventricle and the main and branch pulmonary arteries. Patients will frequently present postnatally with respiratory distress secondary to severely dilated branch pulmonary arteries which place extrinsic compression on the trachea. Tetralogy of Fallot with absent pulmonary valve is rarely associated with a patent ductus arteriosus and often occurs with chromosomal abnormalities.
Echocardiographic Assessment:
- Parasternal long axis: asses VSD anatomy and overriding aorta
- Parasternal short axis at the base: assess the main and branch pulmonary size and degree of pulmonary obstruction and regurgitation
- Parasternal short axis at papillary muscle level: assess right ventricular size and septal configuration
- Apical 4 chamber: assess right ventricular size and systolic function
- Subcostal long and short axis: assess evaluate right ventricular outflow tract for evidence of obstruction
- Suprasternal notch/high parasternal: asses the presence/absence of a patent ductus arteriosus
References:
Lai, W. W. (2009). Echocardiography in pediatric and congenital heart disease: From fetus to adult. Chichester, UK: Wiley-Blackwell.
Brown, J. W., Ruzmetov, M., Vijay, P., Rodefeld, M. D., & Turrentine, M. W. (2006). Surgical Treatment of Absent Pulmonary Valve Syndrome Associated With Bronchial Obstruction. The Annals of Thoracic Surgery, 82(6), 2221-2226. doi:10.1016/j.athoracsur.2006.07.022