Consistency of Blood Pressure Differences Between the Left and Right Arms

Open Access
Publisher Website
Google Scholar
Abstract
The accurate assessment of blood pressure (BP) is vital for the correct diagnosis and treatment of hypertension. Blood pressure measurement guidelines of the American Heart Association,1 World Health Organization–International Society of Hypertension Guidelines,2 European Society of Hypertension–European Society of Cardiology,3 and British Hypertension Society4 recommend that BP should be measured in both arms at the initial patient assessment and that, in the event a difference is observed, the arm with the higher pressure should be used for all future measurements. A disparity in BP between the 2 arms is well recognized as a consequence of anatomical abnormalities such as subclavian artery stenosis,5 but significant interarm BP differences have also been reported in patients without apparent arterial disease. One study6 performed among older patients reported a mean interarm difference of 4.2 vs 3.6 mm Hg, with 10% of patients showing a systolic BP (SBP) difference of more than 10 mm Hg. A second study7 reported corresponding figures of 6.3 vs 5.1 mm Hg, with 20% of the patients showing an SBP difference of more than 10 mm Hg. A third study8 of younger patients with hypertension found a mean interarm difference of 5.4 vs 3.1 mm Hg, with 14.2% of patients showing an SBP difference of more than 10 mm Hg. A fourth study,9 conducted in an emergency department setting, showed a mean interarm difference of 10.5 vs 7.6 mm Hg, with the difference exceeding 10 mm Hg in 38.7% of patients. In contrast, a fifth study10 did not observe such differences.