ULTRASONOGRAPHIC LEFT CARDIAC AXIS DEVIATION - A MARKER FOR FETAL ANOMALIES

Objective: To determine if a relation exists between left cardiac axis deviation and fetal anomalies. Methods: Estimation of cardiac axis wa s attempted prospectively as part of the cardiac examination in approx imately 41,500 second- and third-trimester fetuses scanned between 198 7-1993. Those with heart axes greater than 75 degrees to the left were considered to have left axis deviation. Only cases with postnatal fol low-up were included. Results: Thirty-four fetuses with left cardiac a xis deviation had postnatal follow-up; eight were normal and 26 abnorm al (positive predictive value 76%). Twenty-one fetuses had cardiac abn ormalities (ten of these had additional extracardiac findings), and fi ve had extracardiac findings only. Conclusion: Although left cardiac a xis deviation can occur as an isolated sonographic finding in an other wise normal fetus, most cases will demonstrate abnormalities of cardia c and/or extracardiac anatomy. Left cardiac axis deviation is largely associated with cardiac abnormalities, especially conotruncal anomalie s, which may not be detectable by a four-chamber view alone. Therefore , the cardiac axis should be examined routinely as part of the four-ch amber view of the fetal heart.