An introduction to heart rate variability: methodological considerations and clinical applications

Abstract

Keywords: heart rate variability, heart rate, heart rate dynamics, autonomic nervous system, risk assessment, cardiovascular disease Heart rate variability (HRV), the beat-to-beat variation in either heart rate or the duration of the R-R interval, has become a popular clinical and investigational tool (Task Force of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology, 1996;Billman, 2011). Indeed, the term "heart rate variability" yields nearly 18,000 "hits" when placed in the pubmed search engine. These temporal fluctuations in heart rate exhibit a marked synchrony with respiration (increasing during inspiration and decreasing during expiration-the so called respiratory sinus arrhythmia) and are widely believed to reflect changes in cardiac autonomic regulation (Billman, 2011). Although the exact contributions of the parasympathetic and the sympathetic divisions of the autonomic nervous system to this variability are controversial and remain the subject of active investigation and debate, a number of time and frequency domain techniques have been developed to provide insight into cardiac autonomic regulation in both health and disease (Billman, 2011). It is the purpose of this book to provide a comprehensive assessment of the strengths and limitations of HRV techniques. Particular emphasis will be placed on the application of HRV techniques in the clinic and on the interaction between prevailing heart rate and HRV. This book contains both state-of-the art review and original research articles that have been grouped into two main sections: Methodological Considerations and Clinical Application. A brief summary of the chapters contained in each section follows below. METHODOLOGICAL CONSIDERATIONSThe opening section provides a historical overview of the evolution in the concept of heart rate variability (Billman, 2011) and then describes time domain, frequency domain, and non-linear dynamic analysis techniques (and their limitations) that are commonly used to measure heart rate variability. Heathers (2014) and Billman (2013a) describe methodological issues in the analysis of short-term frequency-domain HRV such as the LF band, normalized units, or the LF/HF ratio as well as the influence of external factors on HRV data. These reviews provide substantial information on mathematical concerns in HRV analysis and on the interpretation of the underlying physiological background of HRV power and highlight the necessity of methodological improvement in HRV measurement. Peltola (2012) evaluates the methods used to edit R-R interval time series and how this editing can influence the results obtained by the HRV analysis. The effects of prevailing HR on HRV are further evaluated in series of review and original research articles.It is not widely appreciated that HRV is significantly associated with average heart rate (HR) and that, as a consequence, HRV actually provides information on two quantities; i.e., HR and its variability (Sacha, 2014a,c). Sacha (2013Sacha ( , 2014b demon...

Influence of Heart Rate in Non-linear HRV Indices as a Sampling Rate Effect Evaluated on Supine and Standing

“…The nonlinear relationship between temporal and complexity HRV indices with respect to HR has been addressed emphasizing the importance of attenuating this effect (Zaza and Lombardi, 2001; Platisa and Gal, 2006; Monfredi et al, 2014; Yaniv et al, 2014b). Furthermore, different mathematical models have demonstrated a relationship between HRV amplitude and HR correcting it (Chiu et al, 2003; Meste et al, 2005; Bailón et al, 2011; Sacha, 2014; Billman et al, 2015). HR correction effect on HRV analysis was studied to predict risk mortality (Pradhapan et al, 2014).…”

Ultra‐short heart rate variability recording reliability: The effect of controlled paced breathing

“…During the fixed breathing pacer of 6 breaths/min there is a sinusoidal variation induction in RR intervals (Vaschillo, Vaschillo, & Lehrer, ). This pattern is related to the synchrony between heart rate and breathing frequency caused by resonant frequency rhythm (Lehrer, Vaschillo, & Vaschillo, ; Lehreret al, ), denominated Respiratory Sinus Arrhythmia (ASR), a phenomenon that represents the increase in HR during inspiration and its reduction during expiration (Billman, Huikuri, Sacha, & Trimmel, ; Yasuma & Hayano, ).…”

Heart rate variability and implication for sport concussion

“…One exploratory area of brain injury biomarker research is heart rate variability (HRV), which is the physiological phenomenon of fluctuation and variation in the duration of cardiac cycles, and is generally believed to reflect autonomic modulatory effects on the cardiovascular system (Task Force, 1996;Parati & Taylor, 2006;Friedman, 2007;Thayer et al, 2012;Reyes del Paso et al, 2013;Billman et al, 2015). Because of this potential to index autonomic nervous system function via cardiovascular measures, HRV has been studied in patients who suffered from severe brain injury (Biswas et al, 2000;Critchley et al, 2003;Keren et al, 2005;Su et al, 2005;Papaioannou et al, 2008).…”