Researchers reveal early heart risks from viral infections

Adenoviral infection triggers arrhythmogenic substrate before myocarditis.


Researchers at VTC’s Fralin Biomedical Research Institute have uncovered an essential finding about fatal viral infections of the heart. Before now, the condition known as myocarditis, caused mainly by the body’s immunological reaction to viral infections, received the most attention.

However, a study led by James Smyth, an associate professor at the institute, shows that the virus can create harmful conditions in the heart even before inflammation occurs.

The finding, which will be published in Circulation Research shortly, provides novel approaches to diagnosing and managing cardiac virus infections. This insight is vital due to the significant number of sudden cardiac deaths caused by viral-related myocarditis, with up to 42% of cases in young adults attributed to this condition.

Smyth said, “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. However, 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.”

Researchers investigated adenovirus, a common cause of heart infections and myocarditis, by replicating the human infection process using Mouse Adenovirus Type-3. They found that the virus damages critical components of the heart’s electrical and communication circuits early in the infection. The study’s principal author, virologist Rachel Padget, emphasized that this disruption happens before symptoms appear.

Padget conducted this research while completing her doctoral degree from the Virginia Tech Translational Biology, Medicine, and Health Graduate Program.

Gap junctions act as communication channels between heart cells. In contrast, ion channels control the balance of ions needed for normal heart electrical activity. Arrhythmias, or irregular heartbeats, are caused by adenoviral infections that interfere with these channels and gates. This disruption can cause sudden cardiac issues, especially in those with active infections. These molecular alterations are now the focus of research to reduce the risk of cardiac problems during viral infections.

Smyth notes that “even if an MRI or echocardiogram may show normal, individuals with acute infections may be suffering from potentially fatal underlying molecular problems. Their goal is to create a blood test that can discover a biomarker to help determine who is more likely to experience arrhythmias. This may result in early intervention and avoiding major cardiac issues in patients with cardiac infections.”

The study provides fresh information on diagnosis and therapy options by illuminating the early heart risks linked to viral infections. Further research is needed to develop practical diagnostic tools and therapeutic strategies to mitigate the dangers of viral infections to heart health.

Journal reference:

  1. Rachel L. Padget, Michael J. Zeitz et al., Acute Adenoviral Infection Elicits an Arrhythmogenic Substrate Prior to Myocarditis. Circulation Research. DOI: 10.1161/CIRCRESAHA.122.322437.