Conduction tissue inflammation or infection is associated with the arrhythmic phenotype of myocarditis, and molecular characterization guided pharmacologic control of arrhythmias in 75% of cases.
Case-Control (n=24)
Does molecular characterization of conduction tissue in patients with an arrhythmic phenotype of myocarditis identify specific etiologies and guide effective targeted therapy?
Molecular characterization of conduction tissue in myocarditis patients with ventricular tachyarrhythmias can identify specific infectious or immune-mediated causes, enabling targeted therapy that may effectively control arrhythmias.
BACKGROUND: Myocarditis can manifest with lone ventricular tachyarrhythmias (LVT). Elective inflammation of conduction tissue (CT) is supposed but unproved. METHODS: Forty-two of 420 patients with biopsy proven myocarditis presented with LVT. Twelve of them included CT sections in endomyocardial biopsies. Real-time polymerase chain reaction (PCR) for viral genomes, immunohistochemistry for viral antigens and Toll like receptor 4 (TLR4) were performed. Twelve myocarditis patients with infarct-like or cardiomyopathic phenotype and CT included in tissue section were used as controls. RESULTS: 0.001). PCR was positive for influenza-A virus in two, herpes simplex virus type 2 (HSV2) in one and adenovirus in one with positive CT immunostaining for viral antigens. In eight patients, negative PCR and TLR4 overexpression suggested an immune-mediated pathway. Patients with influenza-A myocarditis and CT infection responded to oseltamivir, those with HSV2 (Herpes Virus 2) and adenovirus infection died. The eight patients with immune-mediated myocarditis were treated with steroids and azathioprine. Seven of them had no more VT(ventricular tachyarrhythmias)during six-month follow-up. CONCLUSIONS: Arrhythmic phenotype of myocarditis is associated with CT inflammation/infection. Molecular characterization of CT damage may lead to pharmacologic control of arrhythmias in 75% of cases.
Frustaci et al. (Thu,) conducted a case-control in Myocarditis with lone ventricular tachyarrhythmias (n=24). Targeted pharmacologic therapy (antivirals or immunosuppression) vs. Myocarditis patients with infarct-like or cardiomyopathic phenotype was evaluated on Pharmacologic control of arrhythmias. Conduction tissue inflammation or infection is associated with the arrhythmic phenotype of myocarditis, and molecular characterization guided pharmacologic control of arrhythmias in 75% of cases.
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