Brachial and calculated aortic blood pressure differences when measured from the dominant and non-dominant arm

Objective: Inter-arm systolic blood pressure (IASBP) differences ≥10 mmHg are associated with increased cardiovascular risk. Prevalence of IASBP differences is unclear given that studies are mainly in diseased populations and vary in measurement technique (sequential vs simultaneous recording). Moreover, no studies have determined whether dominant or non-dominant arm influences calculated central aortic blood pressure. The purpose of this study was to examine the prevalence of IASBP differences measured at the brachial artery and calculated at the aorta in community dwelling adults. Design and Method: In 76 healthy subjects (34 ± 14 years, 37 male) following at least 5 minutes rest, blood pressure and brachial volumetric displacement waveform were simultaneously recorded in the left and right arm using two identical SphygmoCor XCEL (AtCor Medical) blood pressure devices. Measurements were taken four times in each subject, swapping the devices between arms for each measurement. Within arm brachial systolic and diastolic pressure outliers (interquartile range rule) were removed and repeated measures pairwise analysis conducted. Results: Brachial systolic pressure significantly higher in one arm in 10 of the 76 subjects (13%, average IASBP difference 5.0 ± 0.2 mmHg), of which 5 had higher pressure in the dominant arm. Across all subjects, brachial IASBP difference was 3.2 ± 0.3 mmHg (p < 0.001), of which 1.0 ± 0.5 mmHg (p = 0.050) was accounted by arm dominance. Calculated central systolic pressure was different by 2.1 ± 0.3 mmHg (p < 0.01) but not affected by arm dominance (p = 0.291). Left and right arm differences followed a similar trend (data not shown). Mean pressure differences followed systolic pressure whilst aortic augmentation index (AIx) showed an inter-arm difference, but was not higher in the arm of highest brachial systolic pressure (Table). Conclusions: Dominant/non-dominant arm differences exist for brachial systolic blood pressure (13% of the cohort) but do not influence calculated central aortic blood pressure. However, IASBP differences are largely not related to arm dominance.