Researchers demonstrate that viral infections present early risks to the heart

Fatal viral infections can induce heart disease through various mechanisms. Firstly, some viruses can directly infect heart cells, leading to myocarditis and weakening of the heart muscle. Additionally, viral infections can provoke an exaggerated immune response, resulting in systemic inflammation and damage to blood vessels, thereby increasing the risk of atherosclerosis and cardiovascular events.

Viral infection accounts for the majority of myocarditis cases, leading to up to 42 percent of sudden cardiac deaths in young adults and due to this high occurrence of viral-related myocarditis resulting in sudden cardiac death, the insights are crucial.

"From a clinical perspective, our understanding of viral infection of the heart has focused on inflammation, causing problems with the rate or rhythm of the heartbeat. But we have found an acute stage when the virus first infects the heart and before the body's immune response causes inflammation. So even before the tissue is inflamed, the heart is being set up for arrhythmia." said Smyth.

Researchers studied adenovirus, a common cause of cardiac infection and myocarditis, using Mouse Adenovirus Type-3 to mimic human infection. Adenoviral infection disrupts gap junctions and ion channels in heart cells, affecting communication and electrical activity. This disturbance can lead to irregular heart rhythms (arrhythmias) and potential cardiac complications, particularly during active infections.

They discovered that the virus disrupts crucial components of the heart's communication and electrical systems early in the infection. This disruption can lead to irregular heart rhythms (arrhythmias) and potential cardiac complications, particularly during active infections. Researchers target these molecular changes to mitigate the risk of heart issues in individuals with viral illnesses.

"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. In terms of diagnostics, we can now work and 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." concluded Smyth.

Reference: Rachel L. Padget, Michael J. Zeitz, Grace A. Blair, Xiaobo Wu, Michael D. North, Mira T. Tanenbaum, Kari E. Stanley, Chelsea M. Phillips, D. Ryan King, Samy Lamouille, Robert G. Gourdie, Gregory S. Hoeker, Sharon A. Swanger, Steven Poelzing, James W. Smyth. Journal: Circulation Research, 2024; DOI: 10.1161/CIRCRESAHA.122.322437