This paper describes the development of a fulminant case of Wegener’s granulomatosis in a 70-year-old patient, with the sinus involvement, the right lung and the development of clinically silent asymptomatic renal involvement and sudden cardiac free wall rupture of the left atrium with acute cardiac tamponade. It highlights the rarity of the disease location in this area and so far never described developing insidiously complication ended by a dramatic sudden death. Changes in the myocardium consisted of focal hypertrophy of muscle fibers, the presence of bloody stroke, mfibrosis, scattered infiltration of lymphocyte cells, leukocytes, and histiocytes. Infiltrates were also present around the walls of large vessels in and beyond the wall. Within the myocardium and the surrounding area present inflammatory infiltrates of lymphocytes, histiocytes and blood hemorrhages. This is the only described case of sudden cardiac rupture in the course of Wegener’s granulomatosis.