Only the top three finishers in each heat and the three fastest losers make the semi-finals.
In truth Cuddihy looked well of the pace and it was a major achievement for Cuddihy to get to the starting line at all.
The heat was won by Great Britain’s Christine Ohuruogu in 52.00.
Age 24, from Kilkenny City, Joanne was the first Irish female athlete to run the 400 metres in under 51 seconds.
Joanne comes from a well known medical family and is a fourth year medical student at UCD. She is currently taking a break from her medical studies to avail of a UCD athletics scholarship as she prepares for the Beijing Olympic Games in August.She qualified for Beijingwith a brilliant performance at last years World Championships in Osaka, Japan.
Clearly she is a great prospect for London where she will expect to peak in 2012 aged 28 years of age.