Field validity of heart rate variability metrics produced by QRSTool and CMetX.

Interest in heart rate variability (HRV) metrics as markers of physiological and psychological health continues to grow beyond those with psychophysiological expertise, increasing the importance of developing suitable tools for researchers new to the field. Allen, Chambers, and Towers (2007) developed QRSTool and CMetX software as simple, user-friendly tools that can be used to compute metrics of HRV. In the present study, the authors examined the field validity of these software tools--that is, their validity when used by nonexperts. In a lab with extensive expertise in psychopathology but not psychophysiology, ECG data were obtained from 63 undergraduates at baseline and during a stressor and then processed using QRSTool and CMetX to produce the 10 HRV indices described in Allen et al. (2007). The indices displayed factor structures and patterns of changes from baseline to stressor that were similar to findings from Allen et al. and consistent with how indices of parasympathetic and sympathetic activity should behave. Results support the field validity of QRSTool and CMetX, suggesting that they are useful for nonexperts in psychophysiology interested in measuring HRV.