Persistent Atrial Fibrillation Worsens Heart Rate Variability, Activity and Heart Rate, as Shown by a Continuous Monitoring by Implantable Biventricular Pacemakers in Heart Failure Patients. - PUGLISI, ANDREA; GASPARINI, MAURIZIO; LUNATI, MAURIZIO; SASSARA, MASSIMO; PADELETTI, LUIGI; LANDOLINA, MAURIZIO; BOTTO, GIOVANNI LUCA; VINCENTI, ANTONIO; BIANCHI, STEFANO; DENARO, ALESSANDRA; GRAMMATICO, ANDREA; BORIANI, GIUSEPPE (Journal of Cardiovascular Electrophysiology, 2008)