Hypertensive subjects exhibited greater low-frequency R-R variability during night-time rest compared to normotensives (56 vs 48 nu; P<0.05), indicating reduced day-night sympathetic oscillation.
Observational
Does mild hypertension alter the circadian pattern of neural control of heart period compared to normotension?
Essential hypertension is characterized by a reduced day-night oscillation in sympathetic activity, with higher night-time sympathetic tone compared to normotensives.
Tasa de eventos absoluta: 56% vs 48%
valor p: p=<0.05
We addressed the problem of the circadian changes in neural control of heart period in ambulant hypertensive subjects. A running spectral analysis of R-R variability from Holter tapes provided markers of sympathetic, i.e. low-frequency component (LF) almost equal to 0.10 Hz, and vagal, i.e. high-frequency component (HF) almost equal to 0.25 Hz, controlling activities for the 24-h period of the recording. Significant circadian differences were observed in LF between the two groups of subjects: during night-time rest (0300-0400 h), LF was greater in hypertensives than in normotensives (56 +/- 2 and 48 +/- 2 nu, respectively; P less than 0.05). Furthermore, the difference between daytime and night-time LF values was progressively reduced with increasing severity of the hypertensive state, as assessed by resting arterial pressure levels. Spectral analysis of R-R variability suggests that essential hypertension may be characterized by a reduced day-night oscillation in sympathetic activity than can be quantified non-invasively using this approach.
Guzzetti et al. (Sun,) conducted a observational in Mild hypertension. Hypertension vs. Normotensives was evaluated on Low-frequency component (LF) of R-R variability during night-time rest (0300-0400 h) (p=<0.05). Hypertensive subjects exhibited greater low-frequency R-R variability during night-time rest compared to normotensives (56 vs 48 nu; P<0.05), indicating reduced day-night sympathetic oscillation.