Prevalent low-frequency oscillation of heart rate: novel predictor of mortality after myocardial infarction.
BACKGROUND
This study evaluates a novel method for postinfarction risk stratification based on frequency-domain characteristics of heart rate variability (HRV) in 24-hour Holter recordings.


RESULTS
A new risk predictor, prevalent low-frequency oscillation (PLF), was determined in the placebo population of the European Myocardial Infarction Amiodarone Trial (EMIAT). Frequencies of peaks detected in 5-minute low-frequency HRV spectra were averaged to obtain the PLF index. PLF >or=0.1 Hz was the strongest univariate predictor of all-cause mortality associated with relative risk of 6.4 (95% CI, 3.9 to 10.6; P<10(-12)). In a multivariate Cox's regression model including clinical risk factors, mean RR interval, HRV index, low- and high-frequency HRV spectral power, and heart rate turbulence, PLF was the most powerful mortality predictor, with a relative risk of 4.6 (95% CI, 2.2 to 9.3; P=0.00003). Predictive power of PLF was blindly validated in the population of the Autonomic Tone and Reflexes After Myocardial Infarction (ATRAMI) trial. PLF >or=0.1 Hz was associated with univariate relative risk of 6.1 (95% CI, 2.9 to 12.9; P<10(-5)) for cardiac mortality or resuscitated cardiac arrest. In multivariate Cox's regression model including age, left ventricular ejection fraction, baroreflex sensitivity, mean RR interval, standard deviation of normal RR intervals, low- and high-frequency HRV spectral power, and heart rate turbulence, only left ventricular ejection fraction and PLF were significant predictors, with relative risks of 4.2 (95% CI, 1.5 to 11.7; P=0.007) and 3.6 (95% CI, 1.3 to 10.5; P=0.02), respectively.


CONCLUSIONS
An innovative analysis of frequency-domain HRV, which characterizes the distribution of spectral power within the low-frequency band, is a potent and independent risk stratifier in postinfarction patients.
Department of Cardiological Sciences, St George's Hospital Medical School, London, UK.
Dan
D
Wichterle
Jan
J
Simek
Maria Teresa
MT
La Rovere
Peter J
PJ
Schwartz
A John
AJ
Camm
Marek
M
Malik
D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D000368:Aged; D017704:Baroreflex; D015716:Electrocardiography, Ambulatory; D005060:Europe / Q000453:epidemiology; D005260:Female; D006339:Heart Rate; D006801:Humans; D015993:Life Tables; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000188:drug therapy / Q000401:mortality / Q000503:physiopathology*; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D012306:Risk; D018570:Risk Assessment / Q000379:methods*; D016037:Single-Blind Method; D013318:Stroke Volume; D016019:Survival Analysis; D015912:Thrombolytic Therapy; D018879:Ventricular Premature Complexes / Q000503:physiopathology
D000319:Adrenergic beta-Antagonists