Scientific Sessions 2015 - image of ICD

Implantable cardioverter defibrillators can prevent life-threatening rhythms in patients with a hereditary heart rhythm disorder (Long QT Syndrome), including those who have not previously suffered cardiac arrest, according to research presented at the American Heart Association’s Scientific Sessions 2015.

ICDs are recommended to treat long QT syndrome in patients who have survived cardiac arrest. It isn’t clear, however, if ICDs could be a preventive tool.

Researchers followed 212 Long QT syndrome patients who had ICDs but had not experienced life-threatening events. They analyzed occurrences of life-saving electrical shocks to halt dangerous rhythms, then identified parameters that would help identify patients at high risk for sudden cardiac death.

During an average 9.2 years follow-up, 23 percent of the patients had shocks that terminated life-threatening heart rhythms, and 34 percent had unnecessary shocks.

Researchers found by using genetic information, ECG results and asking patients if they had ever lost consciousness while on beta blocker medication, doctors could better identify high-risk patients that should be treated with ICD implantation.

Patients who were not identified as high-risk could continue to be managed with medications and avoid unnecessary shocks and procedure-related complications, researchers said.