Long-Term Electrocardiographic Changes in Healthcare Workers Following Mild to Moderate Cases of Coronavirus (COVID-19): A Longitudinal Observational Study

Background: The cardiovascular effects of SARS-CoV-2, including autonomic dysregulation, are becoming increasingly recognized, even following mild infections. However, long-term electrocardiographic (ECG) changes remain poorly characterized. Methods: We conducted a prospective study of 151 unvaccinated healthcare workers with RT-PCR-confirmed mild to moderate SARS-CoV-2 infection. Standard 12-lead ECGs were recorded before infection (T0) and at 6-12 months (T1) and >12 months (T2) after infection. Key parameters included heart rate (HR), PR interval, QRS duration, and corrected QT interval (QTc). Results: Heart rate (HR) increased transiently at T1 (p < 0.05) and normalized by T2. Mild but persistent PR interval shortening was observed at both follow-ups (p < 0.01). There were no significant changes in QRS or QTc intervals. No arrhythmias or conduction blocks occurred. ECG alterations were not associated with sex or age, except for greater PR shortening in males. Conclusions: Mild SARS-CoV-2 infection can result in transient sinus tachycardia and subtle PR shortening, which is likely to be a post-viral autonomic effect. Long-term ECG surveillance appears unnecessary in asymptomatic cases.