Recurrence of myocarditis presenting as pacing and sensing failure after implantation of a permanent pacemaker at first onset

A 31-year-old woman was admitted to hospital with loss of consciousness and generalized convulsions. Electrocardiography (ECG) showed complete atriove ntricular block (AV block) with a pulse rate of 30beats/min. Endomyocardial biopsy from the right ventricle showed massive necrosis and degeneration o f myocardial cells with extensive infiltration of lymphocytes into the inte rstitial space. These pathological findings suggested fulminant myocarditis . Following glucocorticoid therapy, the patient became asymptomatic, but th e AV block did not resolve completely and a bifocal pacemaker was implanted . However, similar symptoms recurred 7 years later. An ECG showed pacing an d sensing failure linked to an increase in the pacing threshold and a decre ase in the sensing threshold. Endomyocardial biopsy from the right ventricl e again showed interstitial infiltration with lymphocytes and eosinophils. After glucocorticoid therapy, she became asymptomatic once more, and the im provement in the pacing and sensing failure, and cardiomegaly, was satisfac tory. This patient represents a very rare case of recurrence of acute myoca rditis without progression, as much as 7 years after its first occurrence. Glucocorticoid therapy was still effective in treating the recurrent myocar ditis presenting with pacing and sensing failure.