Objective To establish the relationship between heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure DBP, pulse pressure (PP), and mean arterial pressure (MAP) in paediatric patients from ambulatory blood pressure monitoring (ABPM) records.

Design and methods 100 ABPM studies from 75 children; mean age 12.1 years who underwent 24 h BP monitoring in our paediatric nephrology clinic were analysed. We acquired demographic data and readings of HR, SBP and DBP, PP and MAP from the ABPM records. The relationship between these variables was examined using regression statistical analysis. None of the children were on drugs known to affect heart rate or blood pressure.

Results Highly significant correlation coefficients were found between increasing HR and SBP, DBP and MAP: 0.40 (95% confidence intervals 0.38–0.43), 0.39 (0.36–0.41)and 0.37(0.35–0.39), all p < 0.001 respectively. Boys had a lower mean clinic HR than girls 84 vs 91 bpm p < 0.02. However, there was no difference in the response to increasing HR and BP parameters between the genders. HR and BP parameters correlated more strongly during awake periods than during sleep.

Conclusions In this pilot study, we found that as HR increases above basal, Blood Pressure increases in a predictable fashion. There are differences in the response of BP to increasing HR during asleep and awake periods. This pilot study confirms that we may be able to ‘adjust’ BP readings for tachycardia to improve our interpretation of ABPM.