Sinus arrest and syncope in a young patient with Epstein-Barr virus infection: a case report.

Background: Emerging evidence suggests a potential link between Epstein-Barr virus (EBV) infection and cardiovascular diseases. However, the impact of EBV infection on the development of arrhythmias and conduction abnormalities remains to be fully clarified. Case summary: We present a case report of a healthy 38-year-old Caucasian male who underwent an occupational medicine visit, during which a resting electrocardiogram (ECG) showed numerous premature ventricular contractions. He was later prescribed a stress test. During the test, he experienced a sinus arrest of 6.5 seconds with true syncope during the recovery phase. EBV infection was the only concomitant pathological finding observed during subsequent diagnostic investigations. Initially, it was necessary to rule out all possible cardiac causes of the event, especially in such a young patient. Comprehensive cardiac evaluations, including ECG, echocardiography, cardiac computed tomography, cardiac magnetic resonance, and electrophysiological studies, were normal. After 2 months, both the resting ECG and stress test were completely normal. The final diagnosis for the patient was 'reflex cardioinhibitory syncope'. Accordingly, a pacemaker (PMK) device was not implanted, as the patient was under 40 years old and had no history of recurrent syncope, in accordance with European Guidelines. Discussion: Temporary conditions that may cause conduction abnormalities are a contraindication to PMK implantation. Therefore, it is crucial to always consider EBV infection in the differential diagnosis of cardiac conduction disorders. One hypothesis is that EBV may have specifically affected the sinoatrial node and a few right ventricular outflow tract cells without causing myocarditis signs.