New insights into cardiac arrest in young people

Sydney scientists have released a new study that could provide some families with a clearer insight into why a young loved one may have experienced an otherwise unexplained cardiac arrest and, in some cases, sudden death. Their research has been published in Circulation: Genomic and Precision Medicine.

Arrhythmic right ventricular cardiomyopathy (ARVC) is a poorly understood genetic cardiomyopathy. It occurs if the muscle tissue in the right side of the heart undergoes cell death and is replaced with fat and scar tissue, disrupting the heart’s electrical signals and causing an abnormal heart rhythm.

Researchers from the Centenary Institute, Royal Prince Alfred Hospital, Royal North Shore Hospital and the University of Sydney examined four families in which one family member (under the age of 30 years) had ARVC and experienced a cardiac arrest as a result. In two cases, the patients survived; in the other two cases, the patients died suddenly.

Studies to date suggest patients must exhibit an obvious structural change to their heart before they are at risk of a sudden cardiac episode. This study shows for the first time that this isn’t always the case, with none of the four patients’ hearts exhibiting any structural changes. In all four cases, however, a genetic error in a particular gene called PKP2 was identified.

“This study could force us to re-evaluate how we treat patients with this particular type of cardiomyopathy,” said Professor Chris Semsarian AM, Head of Centenary’s Molecular Cardiology Program. “For example, should we be more aggressive in treating these patients who carry the PKP2 gene error but don’t show any clinical evidence of having this disease?

“It also opens the door for potential gene-targeted therapy further down the track, with the aim of preventing patients with ARVC from experiencing a cardiac arrest.”

Dr Jodie Ingles, lead author on the study and Head of Centenary’s Clinical Cardiac Genetics Group within the Molecular Cardiology Program, says the results may also help to provide closure for some families.

“In many cases of cardiac arrest or sudden death, it can be difficult to identify the precise cause, particularly if the patient’s heart does not show any structural changes,” she said. “Now, we can attribute a specific gene as to why some people die suddenly, in cases that would otherwise go unexplained.”

Image credit: ©stock.adobe.com/au/SasinParaksa

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