title: 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.
abstract: BACKGROUND
  Atrial fibrillation (AF) induces loss of atrial contribution, heart rate irregularity, and fast ventricular rate.
  
  
  OBJECTIVE
  The objectives of the study were to accurately measure AF incidence and to investigate the mutual temporal patterns of AF and heart failure (HF) in patients indicated to cardiac resynchronization therapy.
  
  
  METHODS
  Four hundred ten consecutive patients (70% male, age 69 +/- 11) with advanced HF (NYHA = 3.0 +/- 0.6), low ejection fraction (EF = 27 +/- 9%), and ventricular conduction delay (QRS = 165 +/- 29 ms) received a biventricular pacemaker. Enrolled patients were divided into two groups: G1 = 249 patients with no AF history, G2 = 161 patients with history of paroxysmal/persistent AF.
  
  
  RESULTS
  In a median follow-up of 13 months, AF episodes longer than 5 minutes occurred in 105 of 249 (42.2%) G1 patients and 76 of 161 (47.2%) G2 patients, while AF episodes longer than one day occurred in 14 of 249 (5.6%) G1 patients and in 36 of 161 (22.4%) G2 patients. Device diagnostics monitored daily values of patient activity, night heart rate (NHR), and heart rate variability (HRV). Comparing 30-day periods before AF onset and during persistent AF, significant (P < 0.0001) changes were observed in patient activity, which decreased from 221 +/- 13 to 162 +/- 12 minutes, and in NHR, which increased from 68 +/- 3 to 94 +/- 7 bpm. HRV significantly decreased (from 75 +/- 5 ms before AF onset to 60 +/- 6 ms after AF termination). NHR during AF was significantly (P < 0.01) and inversely correlated (R(2)= 0.73) with activity, with a significant lower activity associated with NHR >or= 88 bpm.
  
  
  CONCLUSIONS
  AF is frequent in HF patients. Persistent AF is associated with statistically significant decrease in patient activity and HRV and NHR increase.
authors.affiliation: Institute of Cardiology, Fatebenefratelli Hospital, Rome, Italy. puglisiandrea@hotmail.com
authors.forename: Andrea
authors.initials: A
authors.lastname: Puglisi
authors.forename: Maurizio
authors.initials: M
authors.lastname: Gasparini
authors.forename: Maurizio
authors.initials: M
authors.lastname: Lunati
authors.forename: Massimo
authors.initials: M
authors.lastname: Sassara
authors.forename: Luigi
authors.initials: L
authors.lastname: Padeletti
authors.forename: Maurizio
authors.initials: M
authors.lastname: Landolina
authors.forename: Giovanni Luca
authors.initials: GL
authors.lastname: Botto
authors.forename: Antonio
authors.initials: A
authors.lastname: Vincenti
authors.forename: Stefano
authors.initials: S
authors.lastname: Bianchi
authors.forename: Alessandra
authors.initials: A
authors.lastname: Denaro
authors.forename: Andrea
authors.initials: A
authors.lastname: Grammatico
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Boriani
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000175:diagnosis* / Q000453:epidemiology* / Q000517:prevention & control; D002908:Chronic Disease; D015716:Electrocardiography, Ambulatory / Q000706:statistics & numerical data*; D005260:Female; D006333:Heart Failure / Q000175:diagnosis* / Q000453:epidemiology* / Q000517:prevention & control; D006339:Heart Rate; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008297:Male; D010138:Pacemaker, Artificial / Q000706:statistics & numerical data*; D015995:Prevalence; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors