Description
A Closer Look at Heart Rate opens with an examination of the latent structures underlying short-term heart rate variability indices in a sample of 96 young adults under 4-min eyes-closed followed by 4-min eyes-open resting-state conditions. Electrocardiograms recorded during the two resting-state conditions were then analyzed using a variety of heart rate variability indices in which latent structures were identified using principal component analysis. Additionally, the authors test the hypothesis that the statistical artefact regression to the mean explains part of the baseline effect. To do this, the regression to the mean effect is illustrated through heart rate recording carried out on 1233 volunteers, from which 137 were randomly selected to obtain an estimate of the stress response. Next, 14,000 antepartum fetal heart rate tracings obtained during 2,000 pregnancies are analyzed. After 30 weeks, fetal behavior progressively changes and differentiates into three main states: active sleep, quiet sleep, and active wakefulness. The fetal heart rate pattern during quiet sleep is usually homogeneous. It appears that a heterogeneous pattern reflecting a specific quiet sleep variant has been unrecognized. In the closing chapter, the role of meditation in cardiovascular risk reduction through beneficial modulation in heart rate, and heart-rate variability is reviewed and discussed. Meditative practices are aimed at training the mind to achieve a state of increased consciousness.
