PMID- 17341391
OWN - NLM
STAT- MEDLINE
DCOM- 20070807
LR  - 20161222
IS  - 1547-5271 (Print)
IS  - 1547-5271 (Linking)
VI  - 4
IP  - 3
DP  - 2007 Mar
TI  - Demonstration of circadian rhythm in heart rate turbulence using novel 
      application of correlator functions.
PG  - 292-300
AB  - BACKGROUND: Demonstration of a circadian rhythm in two parameters of heart rate 
      turbulence--turbulence onset (TO) and turbulence slope (TS)--has been difficult. 
      OBJECTIVE: The aim of this study was to devise a new method for detecting 
      circadian rhythm in noisy data and to apply it to selected Holter recordings from 
      two postmyocardial infarction databases: Cardiac Arrhythmia Suppression Trial 
      (CAST, n = 684) and Innovative Stratification of Arrhythmic Risk (ISAR, n = 327). 
      METHODS: For each patient, TS and TO were calculated for each hour with >4 
      ventricular premature contractions (VPCs). An autocorrelation function 
      Corr(Deltat) = <TS(t) TS(t + Deltat)> then was calculated and averaged over all 
      patients. Positive Corr(Deltat) indicates that TS at a given hour and Deltat 
      hours later are similar. TO was treated likewise. Simulations and mathematical 
      analysis showed that a circadian rhythm required Corr(Deltat) to have a U-shape 
      consisting of positive values near Deltat = 0 and 23 and negative values for 
      intermediate Deltat. Significant deviation of Corr(Deltat) from the correlator 
      function of pure noise was evaluated as a Chi-square value. RESULTS: Circadian 
      patterns were not apparent in hourly averages of TS and TO plotted against clock 
      time, which had large error bars. However, their correlator functions produced 
      Chi-square values of approximately 10 in CAST (both P <.0001) and approximately 3 
      in ISAR (both P <.0001), indicating the presence of circadian rhythmicity. 
      CONCLUSION: Correlator functions may be a powerful tool for detecting the 
      presence of circadian rhythms in noisy data, even with recordings limited to 24 
      hours.
FAU - Watanabe, Mari A
AU  - Watanabe MA
AD  - Department of Internal Medicine, St. Louis University, St. Louis, Missouri 63110, 
      USA. watanabe@slu.edu
FAU - Alford, Mark
AU  - Alford M
FAU - Schneider, Raphael
AU  - Schneider R
FAU - Bauer, Axel
AU  - Bauer A
FAU - Barthel, Petra
AU  - Barthel P
FAU - Stein, Phyllis K
AU  - Stein PK
FAU - Schmidt, Georg
AU  - Schmidt G
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20061118
PL  - United States
TA  - Heart Rhythm
JT  - Heart rhythm
JID - 101200317
RN  - 0 (Adrenergic beta-Antagonists)
SB  - IM
CIN - Heart Rhythm. 2007 Mar;4(3):301-3. PMID: 17341392
MH  - Adrenergic beta-Antagonists/therapeutic use
MH  - Chi-Square Distribution
MH  - *Circadian Rhythm/drug effects
MH  - Databases, Factual
MH  - Electrocardiography, Ambulatory
MH  - Female
MH  - Heart Conduction System/drug effects/physiopathology
MH  - *Heart Rate/drug effects
MH  - Humans
MH  - Male
MH  - Mathematical Computing
MH  - Middle Aged
MH  - Myocardial Infarction/drug therapy/physiopathology
MH  - Predictive Value of Tests
MH  - Signal Processing, Computer-Assisted
MH  - Ventricular Premature Complexes/physiopathology
EDAT- 2007/03/08 09:00
MHDA- 2007/08/08 09:00
CRDT- 2007/03/08 09:00
PHST- 2006/09/22 00:00 [received]
PHST- 2006/11/09 00:00 [accepted]
PHST- 2007/03/08 09:00 [pubmed]
PHST- 2007/08/08 09:00 [medline]
PHST- 2007/03/08 09:00 [entrez]
AID - S1547-5271(06)02172-2 [pii]
AID - 10.1016/j.hrthm.2006.11.016 [doi]
PST - ppublish
SO  - Heart Rhythm. 2007 Mar;4(3):292-300. doi: 10.1016/j.hrthm.2006.11.016. Epub 2006 
      Nov 18.