Kết quả phản ứng tiếp theo viêm hoại tử mô dẫn phát triển và thay thế bằng mô xơ. Những kháng thể này đã được báo cáo với lupus ban đỏ hệ thống, viêm khớp dạng thấp, xơ cứng bì, và hội chứng Sjogren | Congenital atrioventricular block 51 107 108 . The subsequent inflammatory reaction results in necrosis of the developing conduction tissue and replacement with fibrous tissue. These antibodies have been reported with systemic lupus erythematosus rheumatoid arthritis ccleroderma add Sjogren s syndrome 109 110 . Up to 98 of mothers whose offspring have congenital atrioventricular block can be shown to have these antibodies 111 although many of the mothers demonstrate no symptoms or signs of the auto immune disease at the time of gestation 112 . Not all offspring in mothers with systemic lupus erythematosus develop congenital atrioventricular block although high antibody titers anda previous pregnancy complicatedby congenital atrioventricular block are sensitive predictors of risk 113 . As stated eaciles not all cases of complele heart bocck in the young aee due to a congenital interruption of the proximal conducting system. Other causes such as myocarditis trauma or even congenital tumors such as a mesothelioma of the atrioventricular node have been described 114 . A subset of patients with congenital atrioventricular block is prone to development of a cardiomyopathy as part of their genetically inherited condition 115 . An association of a congenital aneurysm of the membranous septum has also been reported 1116. The challenge for the physician referreda young adult with complete atrioventricular block is when to implant a permanent pacemaker. Provided the patient has no symptoms the ventricular rate particularly with exertion is satisfactory no ventricular tachyarrhythmias are docu-mentedandthe echocardiograph andchest radiograph remains within normal limits the patient can be followedregularly without implantation of a permanent pacemaker. Any deterioration in these parameters fulfills the indication for permanent pacing Figure . For adults the 24-hour Holter ambulatory monitor plays an important role. Heart rates less than 40 beats per minute with pauses up
