title: Seasonal trends in atrial fibrillation episodes and physical activity collected daily with a remote monitoring system for cardiac implantable electronic devices.
abstract: BACKGROUND
  Remote monitoring (RM) of cardiac implantable electronic devices is an ideal experimental model to evaluate long-term trends of physiological and clinical data automatically collected from large patient cohorts.
  
  
  OBJECTIVE
  We studied data of atrial fibrillation (AF) and physical activity (PA) transmitted daily during 3.5years from a subgroup of patients enrolled in the HomeGuide trial, a previously conducted study on patients routinely followed with a RM system transmitting clinical and diagnostic data daily.
  
  
  METHODS
  We selected 988 patients (80% male, mean age 68±11) implanted with a pacemaker (16%) or an implantable defibrillator and provided with atrial sensing and movement sensors. Remotely transmitted data were processed in order to obtain AF incidence and time of PA in the form of collective time series daily sampled.
  
  
  RESULTS
  We found that both PA and AF incidence clearly showed seasonal trends with an annual period and inverse correlation. In a first-order autoregressive model the regression coefficient of daily activity to AF incidence was -0.64 (standard error, 0.18, p<0.0001), while the cross-correlation coefficient reached its maximum values at ±180day lags. AF incidence was 14.4% higher and PA was 14.7% lower in winters than in summers (p<0.0001 for both comparisons). Power spectral analysis revealed weekly periodicity in the PA series (corresponding to festivity rest) but not in the AF incidence.
  
  
  CONCLUSIONS
  RM data collected daily from a relatively large patient cohort revealed marked seasonal trends in AF incidence and PA with opposite behavior in winters and summers.
authors.affiliation: Department of Cardiovascular, Dysmetabolic and Aging-associated Diseases, Rome, Italy. Electronic address: federica.censi@iss.it.
authors.forename: Federica
authors.initials: F
authors.lastname: Censi
authors.affiliation: Department of Cardiovascular, Dysmetabolic and Aging-associated Diseases, Rome, Italy. Electronic address: giovanni.calcagnini@iss.it.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Calcagnini
authors.affiliation: Department of Cardiovascular, Dysmetabolic and Aging-associated Diseases, Rome, Italy. Electronic address: eugenio.mattei@iss.it.
authors.forename: Eugenio
authors.initials: E
authors.lastname: Mattei
authors.affiliation: Department of Cardiology, Casilino Hospital, Via Casilina 1049, 00169 Rome, Italy. Electronic address: leonardo.calo@tin.it.
authors.forename: Leonardo
authors.initials: L
authors.lastname: Calò
authors.affiliation: Electrophysiology, Spedali Civili, P.le Spedali Civili 1, 25123 Brescia, Italy. Electronic address: antonio.curnis@libero.it.
authors.forename: Antonio
authors.initials: A
authors.lastname: Curnis
authors.affiliation: UOSD Electrophysiology, Vincenzo Monaldi Hospital, Via L. Bianchi, 80131 Naples, Italy. Electronic address: donofrioant1@gmail.com.
authors.forename: Antonio
authors.initials: A
authors.lastname: D'Onofrio
authors.affiliation: Department of Cardiology, Civil Hospital, Via Togliatti 1, 31044 Montebelluna, Italy. Electronic address: vaccaridiego@gmail.com.
authors.forename: Diego
authors.initials: D
authors.lastname: Vaccari
authors.affiliation: UOC Cardiology, Mater Salutis Hospital, Via Gianella 1, 37045 Legnago, Italy. Electronic address: gabzanot@tin.it.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Zanotto
authors.affiliation: Department of Cardiovascular Diseases, San Filippo Neri Hospital, Rome, Italy. Electronic address: lmorichelli@yahoo.it.
authors.forename: Loredana
authors.initials: L
authors.lastname: Morichelli
authors.affiliation: Clinical Office, Biotronik Italia S.p.a., V.le delle Industrie 11, 20900 Vimodrone, MI, Italy. Electronic address: nicola.rovai@biotronik.com.
authors.forename: Nicola
authors.initials: N
authors.lastname: Rovai
authors.affiliation: Clinical Office, Biotronik Italia S.p.a., V.le delle Industrie 11, 20900 Vimodrone, MI, Italy. Electronic address: alessio.gargaro@biotronik.com.
authors.forename: Alessio
authors.initials: A
authors.lastname: Gargaro
authors.affiliation: Department of Cardiovascular Diseases, San Filippo Neri Hospital, Rome, Italy. Electronic address: renatopietroricci@tin.it.
authors.forename: Renato Pietro
authors.initials: RP
authors.lastname: Ricci
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology; D017147:Defibrillators, Implantable / Q000706:statistics & numerical data; D015716:Electrocardiography, Ambulatory / Q000295:instrumentation / Q000379:methods; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D015994:Incidence; D007558:Italy / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial / Q000706:statistics & numerical data; D058998:Remote Sensing Technology / Q000379:methods; D012621:Seasons; D013223:Statistics as Topic
keywords: Atrial fibrillation; Home monitoring; Physical activity; Seasonality