four chamber view
The four chamber cardiac view is an important and routinely performed view in both fetal echocardiography as well as on a standard second trimester anatomy scan.
Detectable pathology
The four chamber view can only detect some of the congenital cardiac anomalies (~64% according to one study) that can be detected antenatally and these include:
- septal defects
- hypoplastic left heart syndrome
- persistent truncus arteriosus
- presence of echogenic intracardiac foci (EIF)
Anomalies that may not be apparent on the four chamber view alone include transposition of the great arteries and aortic coarctation.
Radiographic features
It is assessed on an axial (transverse) plane through the fetal thorax.
Features to evaluate:
- situs: establish heart on the left side, same side as fetal stomach
- axis: cardiac apex normally points to the left, at an angle of 45°+/-20°
- heart size: should occupy approximately 1/3rd of the thoracic area
- heart location: any mediastinal shift or ectopia cordis
- heart rate: normal 120-160 bpm
- atrial chambers: similar in size, with foramen ovale flap opening to the left atrium
- ventricular chambers: the morphologic right ventricle should be located immediately behind the sternum and is characterized by the presence of the moderator band
- interventricular and interatrial septa (with possible defects)
- atrioventricular valves: tricuspid valve (right heart) septal leaflet inserts into the septum more anterior than the mitral valve (left heart) - the normal valve offset
See also
Siehe auch:
