Left ventricular rupture after double valve replacement in a patient with myocarditis due to myasthenia gravis.

Myasthenia gravis is an autoimmune disease characterised by weakness of the skeletal muscles, with remissions and exacerbations due to antibodies acting on the acetylcholine receptors. This leads to the characteristic defect transmission in the neuromuscular junction. Treatment includes anticholinesterase agents, thymectomy, and immunosuppression. Surgical thymectomy can induce remission or improvement, allowing for reduction in the immunosuppressive treatment. The case of an 84-year-old female patient with myasthenia gravis, aortic valve stenosis, mitral valve regurgitation and myocarditis is described. The development of myocarditis was related to inflammatory cell infiltration, and progressive and additive focal cellular necrosis associated with reactive myocardial fibrosis. After replacement of the mitral valve, complications arose when a rupture of the left ventricular posterior wall occurred, which caused massive bleeding and sudden death on the operating table.