Histopathological Analysis of Endocardium in Patient with Subclinical Cardiac Sarcoidosis Associated with Pacemaker Failure Following External Cardioversion

概要

論文の詳細を見る
In patients with pacemaker implantation the pacemaker failure after administered external cardioversion have been reported resulting in myocardial damage at the electrode-endocardial junction. A 81 y.o. man with DDD (ventricular lead in mid RV septum) pacemaker implantation for the treatment of complete AV block occured hemodynamically unstable ventricular tachycardia (VT). The patient progressed VT storm and 5 times cardioversion were accomplished with 200J (Biphasic), pacemaker failure was occured. The echocardiogram suggested cardiac sarcoidosis. The cause of pacemaker failure is the increase in stimulation threshold of ventricular pacemaker lead. After that, the patient died of cardiac shock. Autopsy showed fibrosis of myocardium extended from basal septum to apex in ventricle in gross. The site of ventricular pacemaker lead is the normal myocardium surrounding fibrosis. In microscopy, the fibrotic change of myocardium revealed the invasion of epithelioid granuloma. The granulomatous inflammation extended to the subendocardium adjacent to the lead tip area which including electrode-endocardial junction. The lead tip area revealed interstitial edema with dilatation of lymph ducts and capillaries. The injury of the survived myocardium due to the application of directcurrent through the pacemaker lead at the RV septum where is adjacent to the lesion of coexisting cardiac sarcoidosis had exhibited pacemaker failure.