Welcome to health care magic. During anomaly scan every aspect of the foetal body parts are assessed. As a part of the scan the cardia is seen in four chamber view, left ventricular out flow tract (LVOT) and Right ventricular outflow tract (RVOT) and ventricle volume. Probably it was higher limit normal or seen prominent - and the scanning doctor might like to send for complete evaluation from a foetal cardiac specialist. Foetal echo is recommended in this conditions. At the same time one will look for other anomalies - as cardia acts as a soft marker. Hope i have answered your query. Any thing to ask do not hesitate. Thank you.