Discrepancy between inducibility of ventricular tachycardia and activity of cardiac sarcoidosis - Requirement of defibrillator implantation for the inactive stage of cardiac sarcoidosis

Monomorphic ventricular tachycardia (VT) developed in two patients with car diac sarcoidosis. Before treatment with prednisolone, technetium or gallium scintigram revealed abnormal accumulation in the heart and bilateral hilar lymph nodes, but programmed electrical stimulation failed to induce VT in either case. Prednisolone was administered and the abnormal accumulation of the scintigra ms disappeared. However, VT became reproducibly inducible, a nd in one of the patients, transient entrainment was demonstrated in clinic al VT morphology. Defibrillators were implanted in both patients. Some VTs associated with cardiac sarcoidosis are due to reentry, and inducibility of VT is not associated with the activity of cardiac sarcoidosis. Even though steroid therapy suppresses the activity of cardiac sarcoidosis, defibrilla tor implantation is necessary to prevent a possible arrhythmic event during the followup.