OBJECTIVE: To determine if a relation exists between left cardiac axis deviation and fetal anomalies. METHODS: Estimation of cardiac axis was attempted prospectively as part of the cardiac examination in approximately 41,500 second- and third-trimester fetuses scanned between 1987-1993. Those with heart axes greater than 75 degrees to the left were considered to have left axis deviation. Only cases with postnatal follow-up were included. RESULTS: Thirty-four fetuses with left cardiac axis deviation had postnatal follow-up; eight were normal and 26 abnormal (positive predictive value 76%). Twenty-one fetuses had cardiac abnormalities (ten of these had additional extracardiac findings), and five had extracardiac findings only. CONCLUSION: Although left cardiac axis deviation can occur as an isolated sonographic finding in an otherwise normal fetus, most cases will demonstrate abnormalities of cardiac and/or extracardiac anatomy. Left cardiac axis deviation is largely associated with cardiac abnormalities, especially conotruncal anomalies, which may not be detectable by a four-chamber view alone. Therefore, the cardiac axis should be examined routinely as part of the four-chamber view of the fetal heart.
OBJECTIVE: To determine if a relation exists between left cardiac axis deviation and fetal anomalies. METHODS: Estimation of cardiac axis was attempted prospectively as part of the cardiac examination in approximately 41,500 second- and third-trimester fetuses scanned between 1987-1993. Those with heart axes greater than 75 degrees to the left were considered to have left axis deviation. Only cases with postnatal follow-up were included. RESULTS: Thirty-four fetuses with left cardiac axis deviation had postnatal follow-up; eight were normal and 26 abnormal (positive predictive value 76%). Twenty-one fetuses had cardiac abnormalities (ten of these had additional extracardiac findings), and five had extracardiac findings only. CONCLUSION: Although left cardiac axis deviation can occur as an isolated sonographic finding in an otherwise normal fetus, most cases will demonstrate abnormalities of cardiac and/or extracardiac anatomy. Left cardiac axis deviation is largely associated with cardiac abnormalities, especially conotruncal anomalies, which may not be detectable by a four-chamber view alone. Therefore, the cardiac axis should be examined routinely as part of the four-chamber view of the fetal heart.