title: Short-term ECG recordings for heart rate assessment in patients with chronic atrial fibrillation.
abstract: BACKGROUND
  There is no consensus on the length of ECG tracing that should be recorded to represent adequate rate control in patients with atrial fibrillation (AFib). The purpose of the study was to examine whether heart rate measurements based on short-term ECGs recorded at different periods of the day may correspond to the mean heart rate and rate irregularity analyzed from standard 24-hour Holter monitoring.
  
  
  METHODS
  The study enrolled 50 consecutive patients with chronic AFib who underwent 24-hour Holter monitoring. Mean heart rate (mHR) and the coefficient of irregularity (CI) were assessed from 5- and 60-minute intervals of Holter recordings in different periods of the day.
  
  
  RESULTS
  The highest correlation in mean heart rate interval within 24 h was found during a 6-hour sample and in the periods 11.00 AM-12.00 PM, 12 PM-1.00 PM, and 1.00 PM-2.00 PM. With respect to irregularity, only the CI measurements based on a 6-hour interval (7.00 AM-1.00 AM) show a correlation > 0.08 compared to data from the 24-hour recording.
  
  
  CONCLUSIONS
  Only long-term (6-hour) recordings provide a high correlation within 24 h in mean heart rate interval and coefficient of irregularity. It seems that the mean heart rate interval in 1-hour periods between 11 AM and 2 PM might be predictive for 24-hour data. Short time recordings of the coefficient of irregularity of heart rate in AFib patients at this moment are not useful in clinical practice for long-term prognosis of ventricular irregularity.
authors.affiliation: Department of Electrocardiology, Medical University of Lodz, Poland.
authors.forename: Michal
authors.initials: M
authors.lastname: Chudzik
authors.affiliation: Department of Electrocardiology, Medical University of Lodz, Poland.
authors.forename: Iwona
authors.initials: I
authors.lastname: Cygankiewicz
authors.affiliation: Department of Electrocardiology, Medical University of Lodz, Poland.
authors.forename: Artur
authors.initials: A
authors.lastname: Klimczak
authors.affiliation: Department of Electrocardiology, Medical University of Lodz, Poland.
authors.forename: Joanna
authors.initials: J
authors.lastname: Lewek
authors.affiliation: Department of Cardiosurgery, Medical University of Lodz, Poland.
authors.forename: Karol
authors.initials: K
authors.lastname: Bartczak
authors.affiliation: Department of Electrocardiology, Medical University of Lodz, Poland.
authors.forename: Jerzy K
authors.initials: JK
authors.lastname: Wranicz
keywords: atrial fibrillation; rate irregularity; ventricular rate control