@article{oai:nagoya.repo.nii.ac.jp:00028700,
 author = {Nakayama, Natsuki and Hayashi, Toshio and Miyachi, Masahiko and Negi, Koji and Watanabe, Koji and Hirai, Makoto},
 issue = {9},
 journal = {Western Journal of Nursing Research},
 month = {Sep},
 note = {Heart rate variability (HRV), especially increased high frequency (HF), has been reported to provide clinically useful prognostic information regarding cardiovascular disease. Napping is an excellent sleep management strategy in older adults. This study was conducted to clarify the effect of napping on HRV in older adult patients with cardiovascular risk factors. The patients were divided into two groups: one group of 32 patients who reported napping (nap group) and another group of 45 patients who did not report napping (nonnap group). The HRV was calculated in terms of the HF component over 24 hr during wakefulness, sleep, and 1 hr after sleep onset. The HF in the nap group was significantly higher than that in the nonnap group during all times measured. In addition, napping was a significant predictor of increased HF. This study shows the effectiveness of napping in the daily lives of patients with cardiovascular risk factors.},
 pages = {1241--1253},
 title = {Napping Improves HRV in Older Patients With Cardiovascular Risk Factors},
 volume = {41},
 year = {2019}
}