Programmed electrical stimulation of the heart: how, when and where.

In the last 15 years programmed electrical stimulation of the heart has been used to evaluate the site of origin, mechanisms and pathways of tachycardias and to select the best therapeutic approach for each particular patient. Recently, it has also been used increasingly to try to identify patients at risk of sudden arrhythmic death. The method of programmed electrical stimulation of the heart is reviewed and its indications are considered; the type of centres that should be performing these studies is also discussed.