IES-ACap: Influence of Atrial Pulse Width in the Behaviour of ACap™ Confirm Algorithm.

Inclusion Criteria: * Patient has an indication for implantation of a dual-chamber pacemaker; * Patient is older than 18 years of age * Patient has signed the study specific Informed consent document. * Primo implant. Exclusion Criteria: * Patient is pregnant or nursing * Patient is less than 18 years of age * Patient is in New York Heart Association (NYHA) class III and IV. * Patient has a pacemaker replacement; * Patient is unable to attend the follow-up visits;