Simple Blood Test Could Detect Risk of Viral Infection-Induced Cardiac Arrest

Myocarditis, an inflammation of the heart often caused by the body's immune response to a viral infection, can cause sudden cardiac death. Alarmingly, myocarditis accounts for up to 42% of sudden cardiac deaths in young adults, with viral infection being the primary cause. Traditionally, clinical understanding has focused on how inflammation affects heart rate or rhythm. Now, a new understanding from the latest research suggests completely different directions to diagnose and treat viral infections affecting the heart

A new study led by scientists from the Fralin Biomedical Research Institute at Virginia Tech (Blacksburg, VA, USA) has discovered that the virus itself can create dangerous conditions in the heart even before inflammation begins. The study identified an acute phase where the virus first invades the heart, preceding the onset of inflammation due to the body’s immune response. This early infection stage sets the stage for arrhythmias before any tissue inflammation. The research specifically examined adenovirus, often involved in cardiac infections and myocarditis, using Mouse Adenovirus Type-3 to mimic the human infection process. They discovered that at the onset of infection, the virus interferes with essential elements of the heart’s communication and electrical systems, leading to potential disruptions even before symptoms appear. The infection affects the heart's gap junctions, the communication channels between heart cells, and ion channels, the regulatory gates in cell membranes essential for maintaining ion balance crucial for normal heart electrical activity and beating.

When these communication systems and regulators are disturbed by the adenoviral infection, the heart may develop irregular electrical activity patterns known as arrhythmias, impacting its ability to beat and pump blood effectively. This can result in sudden cardiac issues, particularly in individuals with active infections. With the focus now shifting to molecular-level interventions targeting heart arrhythmias caused by viral infections, the researchers now plan to explore methods to detect blood biomarkers indicative of these severe conditions. The aim is to identify high-risk individuals through a simple blood test at the doctor's office, potentially transforming the approach to managing viral cardiac infections.

“Individuals who have acute infections can look normal by MRI and echocardiography, but when we delved into the molecular level, we saw that something very dangerous could occur,” said James Smyth, associate professor at the Fralin Biomedical Research Institute, who led the research. “In terms of diagnostics, we can now work with our colleagues here to start looking ways to analyze blood for a biomarker of the more serious problem. People get cardiac infections all the time and they recover. But can we identify what's different about individuals that are at a higher risk to have the arrhythmia, possibly through a simple blood test in the doctor's office.”

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