Myocarditis and pericarditis are common pathologies in the general population, which pose significant challenges to practitioners for both diagnosis and treatment due to the unique characteristics of diagnosis verification and lack of clear understanding of the diseases pathogenesis. This publication discusses the primary mechanisms of inflammatory diseases development of the myocardium and pericardium based on innate and acquired immunity disorders, including data from our research confirming the autoimmune and autoinflammatory nature of these diseases. The paper presents the main clinical manifestations and laboratory markers that enable differential diagnosis between autoimmune and autoinflammatory heart diseases. Additionally, it provides an evidence-based approach to the effectiveness of various anti-inflammatory and immunosuppressive drugs in different types and stages of inflammatory diseases of the myocardium and pericardium.