Selección del modo de estimulación en las bradiarritmias. Controversias sobre la indicación del modo AAI o el modo DDD en la enfermedad del nódulo sinusal y sobre la utilización del modo VDD en el bloqueo auriculoventricular

Since cardiac pacing was introduced for the treatment of cardiac bradyarrhythmias in the 1950s, implantable cardiac pacemakers have become increasingly sophisticated and there have been continuous attempts to enable them to approximate more closely the normal physiologic functioning of the heart. At the same time, indications for pacemaker implantation have been changing in recent years and a number of expert consensuses have been reached. These are contained in documents (i.e., clinical practice guidelines) based on clinical trails and on the current level of evidence for each indication. Nevertheless, there continue to be demonstrable differences between clearly established recommendations and the pacing modes used for treating symptomatic bradyarrhythmias. Probably, the two pacing modes exhibiting the greatest difference in practice are the AAI and VDD modes. This article contains a review of indications for cardiac pacing, with an emphasis on newly revealed data on pacing modes, pacing sites, and the undesirable side effects of cardiac pacing. In addition, there is a discussion of current controversies about the AAI mode versus the DDD mode in sick sinus syndrome and about use of the VDD mode for atrioventricular block.