[Electrophysiology of pacemakers by demand. Critical analysis]

The adequate interpretation of cardiac arrhythmias should be done in context with the clinical facts. In case of arrhythmias induced by pacemakers, it is essential to have detailed information about the characteristics of the electronic instrument. This paper shows, that only with precise information about the electrophysiological facts of a certain instrument, it is possible to diagnose the origin of an arrhythmia, its significance related to normal function or disfunction of the apparatus and the proper measures can be taken for correcting the disorder. Examples of clinical cases have been presented, and undoubtedly a growing improvement in the elaboration of the electronic instruments, will enrich, the already ample field of cardiac arrhythmias. All of it will lead to an undoubtful benefit for patients, medical personnel who are involved in the electric treatment of the disturbances in rhythm and conduction.