Purpose: To describe the influence of cardiac conduction tissue infection by Influenza A virus.
Methods and results: A 54-year-old man with non-sustained ventricular tachycardia underwent noninvasive and invasive cardiac studies including left ventricular endomyocardial biopsy (LVEMB). Non-invasive studies showed normal cardiac parameters with no signal abnormalities. LVEMB revealed an influenza virus focal myocarditis with inflammatory infiltration of conduction tissue. Non-invasive studies showed normal cardiac parameters with preserved bi-ventricular function. CMR failed to show signal abnormalities including edema and areas of late-gadolinium enhancement. Endomyocardial biopsy (EMB) revealed an influenza virus focal lymphocytic myocarditis. Biopsy samples included sections of conduction tissue with inflammatory infiltration and cell necrosis. Therapy with oseltamivir was followed by disappearance of electrical instability at ECG and Holter monitoring.
Conclusion: Acute myocarditis in its arrhythmic phenotype is probably characterized by a significant inflammation of conduction tissue. Antiviral agents have an actually underestimated and potentially more contributive therapeutic role.
Keywords: Cardiac arrhythmias; Cardiac conduction tissue; Myocarditis.