Advanced algorithms can lead to electrocardiographic misinterpretations.

We observed a patient with syncope, who implanted a pacemaker with advanced algorithms such as "atrial-tachy response" and "dynamic atrio-ventricular delay". After one year, conventional ECG Holter showed pacemaker malfunction, wrongly attributed to exposure to electromagnetic field. In fact, telemetry revealed an inappropriate programming and solved our case. Holter monitoring is commonly performed in the evaluation of pacemaker malfunction, albeit it remains a quite shallow diagnostic method especially to detect electromagnetic interferences. New algorithms seem important, but it is reasonable to obtain more suitable analytical tools, too. Copyright 2008 Elsevier Ireland Ltd. All rights reserved.