Differences in blood pressure values by simultaneous auscultation of Korotkoff sounds inside the cuff and in the antecubital fossa

Abstract

To elucidate whether auscultation of the Korotkoff sounds inside the cuff and in the antecubital fossa leads to different blood pressure (BP) values we measured BP at both sites simultaneously with identical flat stethoscopes in a same-arm test design (part A) in 64 normotensive (N: 32 men, 32 women; mean age: 38.7 ± 15.1 years) and 67 hypertensive subjects (H: 36 men, 31 women; mean age: 44.6 ± 12.9 years), and additionally in a same- and opposite-arm test design (part B) in 20 normotensive young women. While in part A systolic BP measured inside the cuff was only slightly higher (N: +1.6 ± 3.2 mm Hg; H: +1.0 ± 1.4 mm Hg), diastolic BP was considerably lower (N: −10.6 ± 5.6 mm Hg; H: −8.4 ± 4.9 mm Hg). This result was corroborated by part B with differences in systolic/diastolic BP of +0.8 ± 1.0/−8.5 ± 2.2 mm Hg in the same-arm test and +0.4 ± 4.8/−10.6 ± 5.2 mm Hg in the opposite-arm test. Subject’s age was the main variable determining differences in diastolic BP with significantly higher differences in younger than in older subjects, indicating that the elastic properties of arteries may be responsible for these differences. Our results demonstrate that a modification in the auscultatory technique of BP measurement produces significantly different diastolic BP values, the magnitude of which is important for our conceptions of threshold and target values in diagnosing and treating hypertension.