Doctors say a new screening programme for Sudden Adult Death Syndrome will simplify the process of detecting the disease.
From this month family members as young as eight will be screened through the one programme at the Mater Hospital in Dublin.
So far 1,100 families have been screened, but now the system will allow doctors to look at results from adults and children together.
The Mater Foundation's annual heart appeal aims to raise €300,000 so they can continue to offer screening this month.
Paediatric Cardiologist Dr Terry Prendiville says it is a significant step.
Dr Prendiville said: "We'll be seeing children, their siblings and parents, along with their extended family members referred in by their GPs or consultants for family screening.
"We anticipate a large clinical need for such a service and we'll combine our skill in Crumlin with the resources at the Mater to provide the service under the one roof at the Mater Hospital."