Heart Rate Variability Measures and Sudden Cardiac Death Risk.

<p>Association between heart rate variability measures and sudden cardiac death incidence presented as hazard ratios (solid line) and 95% confidence intervals (shaded area). Results from Cox proportional hazards model with heart rate variability measures modeled using restricted cubic splines, adjusted for age, sex, and race. Median value of heart rate variability measures was considered the reference (HR = 1). The x-axis is presented using an inverted scale.