Novel methods of heart rate dynamics, such as heart rate turbulence and deceleration capacity, may provide better prognostic information for cardiovascular events than traditional HRV measures.
Do novel methods of heart rate dynamics analysis provide better prognostic information than traditional HRV measures?
Novel nonlinear heart rate dynamics indices show promise in predicting cardiovascular events and mortality better than traditional HRV measures, though they remain largely in the research domain.
Heart rate variability (HRV) has been conventionally analysed with time- and frequency-domain methods, which measure the overall magnitude of RR interval fluctuations around its mean value or the magnitude of fluctuations in some predetermined frequencies. Analysis of heart rate dynamics by novel methods, such as heart rate turbulence after ventricular premature beats, deceleration capacity of heart rate and methods based on chaos theory and nonlinear system theory, have gained recent interest. Recent observational studies have suggested that some indices describing nonlinear heart rate dynamics, such as fractal scaling exponents, heart rate turbulence and deceleration capacity, may provide useful prognostic information in various clinical settings and their reproducibility may be better than that of traditional indices. For example, the short-term fractal scaling exponent measured by the detrended fluctuation analysis method has been shown to predict fatal cardiovascular events in various populations. Similarly, heart rate turbulence and deceleration capacity have performed better than traditional HRV measures in predicting mortality in post-infarction patients. Approximate entropy, a nonlinear index of heart rate dynamics, which describes the complexity of RR interval behaviour, has provided information on the vulnerability to atrial fibrillation. There are many other nonlinear indices which also give information on the characteristics of heart rate dynamics, but their clinical usefulness is not as well established. Although the concepts of nonlinear dynamics, fractal mathematics and complexity measures of heart rate behaviour, heart rate turbulence, deceleration capacity in relation to cardiovascular physiology or various cardiovascular events are still far away from clinical medicine, they are a fruitful area for research to expand our knowledge concerning the behaviour of cardiovascular oscillations in normal healthy conditions as well as in disease states.
Huikuri et al. (Fri,) conducted a review in Cardiovascular events and mortality. Novel methods of heart rate dynamics (e.g., nonlinear indices, heart rate turbulence, deceleration capacity) vs. Traditional heart rate variability measures was evaluated. Novel methods of heart rate dynamics, such as heart rate turbulence and deceleration capacity, may provide better prognostic information for cardiovascular events than traditional HRV measures.