Congenital AV Block

Abstract

Congenital complete atrioventricular block (CCAVB) has been recognized for almost 100 years. First described by Morquio1 in 1901, it has been of interest in the past primarily because of the risk of Stokes-Adams attacks or sudden cardiac death in these patients.2 3 4 5 6 As a result of some of these studies4 5 6 and others,7 8 the Committee on Pacemaker Implantation published the American College of Cardiology/American Heart Association Task Force Report in 19919 with specific indications for implantation of a pacemaker in the presence of CCAVB. Although this syndrome is not diagnosed solely in children, the section under which these guidelines appear is “Indications for Permanent Pacing in Children.” This certainly makes sense from the perspective that this disease is congenital in nature and initially recognized in childhood. With the advent of fetal echocardiography, in utero diagnosis of CCAVB has resulted in earlier intervention in newborns. Heightened suspicion of the possibility of CCAVB in children born to mothers with connective tissue disease, especially systemic lupus erythematosis, has had the same consequence. To those faced with making the difficult decision of when to implant a pacemaker in an infant or child, arbitrary guidelines can be of concern. Should an asymptomatic newborn be referred for a pacemaker if the average heart rate when awake is found to be 58 beats per minute, or must this be done only if it is less than the recommended value of 55 beats per minute? What is the best plan for a 6-year-old referred to the clinic because of a murmur recognized during a school physical examination in whom complete AV block incidentally happens to be found on the ECG? The child’s parents give a history that the child seems “normal” to them in terms of keeping up …