Medica Jadertina, Vol. 41 No. 1-2, 2011.
Original scientific paper
Changes in heart rate variability during working and non-working nights
Ana Slišković
orcid.org/0000-0002-5621-648X
; Sveučilište u Zadru, Odjel za psihologiju, Obala kralja Petra Krešimira IV, 2, 23000 Zadar
Ilija Manenica
; Sveučilište u Zadru, Odjel za psihologiju, Obala kralja Petra Krešimira IV 2, 23000 Zadar
Abstract
The aim of this study was to compare levels and patterns of heart rate variability during working night shifts and the same period of non-working nights. Eight nurses from the Surgical Department of Zadar Hospital, aged 25-33, participated in this study. The study included continuous recordings of cardiac activity during 10 hours of night-shift working (9.00 pm – 7.00 am) and during the equivalent non-working night periods.
As expected, the analyses showed differences in the levels of cardiac activity between working and nonworking nights. Non-working nights were characterised by longer R-R intervals, higher variability indices
and greater parasympathetic effects on cardiac activity, while their patterns of changes and spectral compositions were rather similar to those obtained during working nights.
The obtained results showed the supremacy of the circadian pattern of changes, i.e. parasympathetic prevalence, during both working and non-working nights. Parasympathetic prevalence during night shift working seemed inappropriate since normal working implies sympathetic activity. This is particularly true for the periods between 4.00 and 6.00 am, when various parameters indicated almost the same level of arousal during working and non-working nights. Certainly, the lack of sympathetic activity and parasympathetic dominance during working nights represents a discrepancy between the work requirements and the momentary capabilities of the organism to meet them. Due to this, it represents a major source of
stress in night-shift working.
Keywords
heart rate variability; shift working; circadian pattern; sympathetic and vagal modulation of cardiac activity
Hrčak ID:
70294
URI
Publication date:
6.7.2011.
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