October 1, 1987Journal of Hypertension
Role of Heart Rate Variability in the Production of Blood Pressure Variability in Man
Key result
Intravenous atropine reduced heart rate variability by 65.3% in supine and 48.4% in exercising subjects without attenuating blood pressure variability, ruling out a cause-effect link.
Why the study?
Does reducing heart rate variability with atropine reduce blood pressure variability in essential hypertensive subjects?
Population
17 essential hypertensive subjects (10 assigned to atropine [5 supine, 5 exercising], 7 assigned to saline)
Comparison
Atropine 0.04 mg/kg body weight injected… vs Intravenous saline
Design
Other
Follow-up
1 hour
Authors
Discussion
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Implication
Concordant 24-h BP-HR changes observed; leaves open central vs. cardiac-output mechanisms in small observational cohorts.
Key Points
- To explore the relationship between heart rate variability and blood pressure variability in hypertensive subjects.
- 10 hypertensive subjects evaluated under two conditions: atropine injection and saline control.
- Blood pressure and heart rate were recorded intra-arterially during 1 hour in supine and exercising states.
- Variations were analyzed using variation coefficients computed from the recordings.
- Atropine reduced heart rate variability by 65.3% (supine) and 48.4% (exercising).
- Supine blood pressure variability modestly decreased, while exercising saw a 30.4% increase in blood pressure variability.
- No changes in variability were observed with saline injection.
Structured PICO
Does reducing heart rate variability with atropine reduce blood pressure variability in essential hypertensive subjects?
P
Population
17 essential hypertensive subjects evaluated during supine and exercising conditions to assess the relationship between heart rate and blood pressure variability.
I
Intervention
Atropine 0.04 mg/kg body weight injected intravenously (i.v.)
C
Comparator
Intravenous saline
O
Outcome
Blood pressure and heart rate variabilities (variation coefficients) over 1 hoursurrogate
Heart rate variability does not cause blood pressure variability, and heart rate may actually play an anti-oscillatory role to stabilize blood pressure during exercise.
Cite This Study
Parati et al. (1987) studied Essential hypertension (n=17). Atropine vs. Saline was evaluated on One-hour blood pressure and heart rate variabilities (variation coefficients). Intravenous atropine reduced heart rate variability by 65.3% in supine and 48.4% in exercising subjects without attenuating blood pressure variability, ruling out a cause-effect link.