title: The detrended fluctuation analysis of acute-phase heart-rate variability in acute coronary syndromes - a pilot study.
abstract: Heart-rate variability (HRV) analyzed by detrended fluctuation analysis (DFA), which resulted in a short-term fractal exponent - alpha, has prognostic implication in chronic phase of heart failure and survivors of myocardial infarction. We adopted DFA to study the acute-phase HRV in acute coronary syndromes (ACS) by recruiting 30 age- and co-morbidity-matched adults in acute-stress simulation in comparison with 33 consecutive ACS patients. The 30 volunteers got stepwise elevated alpha with increased intensity of exercise (0.95+/-0.050 to 1.07+/-0.084 to 1.20+/-0.083, p<0.05). The alpha of 33 ACS patients correlated with the complexity of post-MI course (1.004+/-0.0080 in non-complicated vs. 1.216+/-0.058 in complicated p<0.05). No significance existed in categories of age, ACS type, numbers of diseased vessel, infarct-related artery or Killip classification. The increased alpha value of DFA may imply unresolved cardiac stress which demands further attention.
authors.forename: Ho-Tsung
authors.initials: HT
authors.lastname: Hsin
authors.forename: Chi-Yu
authors.initials: CY
authors.lastname: Yang
authors.forename: Dong-Feng
authors.initials: DF
authors.lastname: Yeih
authors.forename: Jiann-Shing
authors.initials: JS
authors.lastname: Shieh
authors.forename: Ai-Hsien
authors.initials: AH
authors.lastname: Li
mesh_terms: D054058:Acute Coronary Syndrome / Q000175:diagnosis* / Q000503:physiopathology*; D000368:Aged; D015716:Electrocardiography, Ambulatory; D005080:Exercise Test / Q000379:methods*; D005260:Female; D017709:Fractals; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008955:Models, Cardiovascular; D011379:Prognosis