Ultrastructural alterations of the conduction system in mice exhibiting sinus arrest or heart block during Coxsackievirus B3 acute myocarditis.

摘要: Abstract By light and electron microscopy we studied the sinus nodes atrioventricular (AV) conducting tissue of six C3HHe mice having coxsackievirus B3 acute myocarditis. Sinus arrest was documented in all mice, second- or third-degree AV block three mice. Although myocarditic changes conduction system, especially node, were less than those atrial ventricular working myocardium, there distinct abnormalities within both node hearts. Important ultrastructural alterations inflammatory cell infiltrates significant injury specialized cells neural tissue. Specialized showed various features degeneration necrosis. Neural damage included axons Schwann disorganization neuromuscular junctions. Inflammatory cells, particularly macrophages, often intimate contact with injured Interstitial edema bleeding lymphatic vessel dilatation also observed. These pathologic are considered to play an important role development disturbances rhythm conduction.