Newborn babies should be screened for heart abnormalities to reduce the risk of cot death, researchers say.
The researchers say screening could save lives
Italy is considering a screening programme after a University of Pavia pilot study suggested 30 babies' lives could be saved each year.
New Scientist magazine reports the researcher leading the study believes many cot deaths are caused by the rare heart complaint long QT syndrome.
But UK sudden infant death experts said heart conditions were a rare cause.
They said, while screening would be worthwhile if it could save lives, it would have to compete for funding
The Italian researchers have screened 21,000 babies so far. They aim to screen a total of 50,000.
Electrocardiograms (ECGs) are being recorded for all babies attending 16 Italian clinics.
The ECGs are then digitised and sent to a central laboratory to be analysed.
Any baby whose QT interval - the time for electrical activation and inactivation of the ventricles - was longer than 470 milliseconds is tested for genetic mutations linked to long QT.
The normal period is 440 milliseconds.
The team, led by Dr Peter Schwartz, has so far detected 24 babies with worryingly long QT intervals. Of the five who have undergone genetic testing, four have been found to have mutations known to cause the condition.
The screening programme has also picked up three babies with other rare and potentially fatal heart conditions.
None of the babies had shown any symptoms of being ill.
From this and previous research, the doctors calculated that between 10 and 15% of all cases of sudden infant death syndrome (SIDS) are linked to fatal heart rhythms.
They conclude identifying and treating these babies could lead to up to a tenth of the 300 SIDS cases in Italy each year.
The researchers are currently carrying out another study analysing babies who died from SIDS to see if any carried the long QT mutations.
The Italian parliament is currently considering a bill under which heart screening would be offered to all parents.
A finance committee is expected to decide shortly whether or not to proceed. The programme would cost around 30 million euros a year.
Dr John Camm, a spokesman for the British Heart Foundation, said the cost was reasonable: "It would be well worthwhile saving 30 lives a year."
But he said that, in the UK, such a programme would have to compete for funding with many other proposed screening programmes.
Dr Michael Vincent, a cardiologist at the University of Utah, told New Scientist: "Paediatric consultants have been fairly sceptical of Schwartz's previous findings."
But he said the latest results may change people's opinions.
However, UK experts were cautious about backing Dr Schwartz's suggestions for national screening programmes.
Paediatrician Richard Wilson, of the Foundation for the Study of Infant Deaths, said: "Everybody believes that a small percentage of babies die of arrhythmias.
"But I don't think there is anybody in this country that would believe 10% of SIDS cases are due to long QT."
In the past, there were concerns the difficulties in interpreting ECGs carried out on newborn babies could lead to a high rate of "false-positive" results, and many children could be treated unnecessarily.
But the availability of genetic testing, allowing gene mutations to be detected, means treatment could be limited to those babies who carry one of them.