Presentation
Tertiary review for fetal echocardiography.
Patient Data
Four chamber view (4CV)
Four chamber view demonstrates a perimembranous VSD. Right ventricular hypertrophy may or may not be seen on the antenatal 4CV.
Lt ventricular outflow...
Lt ventricular outflow tract LVOT or 5 chamber view
The left ventricular outflow tract is seen to be overriding the ventricular septum. This in association with the ventricular septal defect is referred to as a malaligned VSD. The color images demonstrate filling of the LVOT from both the left and right ventricles with more than 50% of flow coming from the left ventricle. The LVOT is dilated.
Also, note the left axis deviation.
Rt Vent outflow tract (3VV)
In the scenario of TOF with pulmonary stenosis, the three-vessel view shows the narrow right ventricular outflow tract and dilated aorta.
This is in contrast to a TOF with pulmonary atresia, where the RVOT is absent in this view, and to a TOF with dysplastic pulmonary valve syndrome, where there is a dilated RVOT with turbulent flow.
3 vessel trachea 3VT view
In the scenario of TOF with pulmonary stenosis, the 3VT view demonstrates a narrow duct with forward flow.
This is in contrast to a TOF with pulmonary atresia, where there is reverse flow in the duct, and to a TOF with dysplastic pulmonary valve syndrome, where the duct is typically absent.
Case Discussion
There are a number of different subtypes of tetralogy of Fallot: Tetralogy of Fallot with pulmonary stenosis (75%), Tetralogy of Fallot with pulmonary atresia (20%) and dysplastic (absent/ring) pulmonary valve syndrome (5%).
This case demonstrates the typical findings on the standard fetal echo views in a case of tetralogy of Fallot with pulmonary stenosis.
Images courtesy of Dr Simon Meagher