TUESDAY, Feb. 28 (HealthDay News) -- Researchers who used family trees dating back to 1811 to estimate the death risk for people with inherited heart rhythm disorders say their findings can help doctors determine when to screen and treat today's patients with these disorders.
Sudden cardiac death can occur in apparently healthy people due to heart rhythm disorders. Genetic testing can identify people with an inherited heart rhythm disorder (arrhythmia), but that raises questions about how and when to treat children who may not yet be experiencing symptoms, which can take years to develop.
In the study, researchers used Dutch archives to reconstruct the family trees for patients with inherited heart conditions, including long QT syndrome, SCN5a-overlap syndrome, CPVT and Brugada syndrome. The arrhythmia-associated gene mutations examined in the study are rare. However, the children of people who carry one of these mutations have a 50 percent chance of inheriting it.
The investigators were able to identify age ranges that were associated with an increased risk of death among people who had the mutations but had not yet been diagnosed or treated for the condition.
Among the findings:
The study appears in the current issue of the journal Circulation: Cardiovascular Genetics.
"We have to be careful not to draw conclusions for families with arrhythmias caused by different mutations," lead researcher Dr. Eline Nannenberg, a clinical geneticist at the Academic Medical Center in Amsterdam, said in a journal news release.
"However, this new data can guide screening. In LQTS1, we advise starting genetic and heart screening of first-degree family members (children, siblings, parents) at a very young age," Nannenberg added.
Female patients who have Brugada syndrome but no symptoms may not need invasive treatment for the first 30 years of life, but should follow standard prevention measures, such as fighting fever, according to the researchers.
In people with SCN5a-overlap syndrome, it may be possible to delay implantation of a pacemaker or implantable cardioverter-defibrillator (ICD) until after age 5, they noted.
The Heart Rhythm Society has more about heart rhythm disorders.
-- Robert Preidt
SOURCE: Circulation: Cardiovascular Genetics, news release, Feb. 28, 2012
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