Comparison of Direct vs. Indirect Blood Pressure Measurements on Treadmill and Bicycle in Hypertensive Responders

Saghiv M,Goldhammer E

doi:10.4172/2161-1459.1000215

Abstract

Objectives: This study tested whether the systolic and diastolic blood pressures measured simultaneously by direct and indirect methods provide similar readings for blood pressure response during symptom-limited exercise on a treadmill and bicycle, and if it can be used to monitor blood pressure in hypertensive patients treated with β- blockers. Method: Comparisons were made with simultaneously determined intra-arterial catheter and auscultation measurements on a treadmill and bicycle. Eight hypertensive patients (41.9 ± 2.0 years) active participants in supervised aerobic programs (12.1 ± 1.2 METs work capacity) for at least 12 months were recruited to the study. Results: At rest, indirect systolic pressure was highly correlated with the direct method (r=0.85), with mean of 139 ± 7 and 134 ± 6 mmHg, respectively, at peak treadmill exercise (r=0.90), with mean of 198 ± 11 and 189 ± 9 and bicycle (r=0.92) with mean of 204 ± 10 196±9 mmHg respectively. Indirect diastolic blood pressure correlates well with intra-arterial at rest (r=0.82), with mean of 96 ± 11 and 88 ± 9 mmHg, respectively. However, at peak treadmill exercise, the correlation coefficient between the direct and the indirect methods was low (r=0.40), with mean of 105 ± 9 and 112 ± 12 mmHg, respectively. At peak bicycle exercise correlation was (r=0.58) with mean of 107 ± 9 and 112 ± 12 mmHg. Conclusions: These results suggest that at peak treadmill exercise and bicycle, the indirect method tends to bias low compared with direct therefore it is not valid for the assessment of diastolic pressure in hypertensive patients. Intensity should be considered when using cardiovascular variables as outcome measures.

Highlights

Blood pressure (BP), like all biological variables, varies widely in different people and, in the same individual, at different times of the day
Hypertensive responders have a long term medical condition in which the BP in the arteries is persistently elevated [5], they are characterized by a dramatic rise in systolic blood pressure during aerobic exercise [6]
The present study demonstrated that at rest and peak dynamic exercises systolic BP values reached by the indirect method correlated highly with the direct recordings

Summary

Introduction

Blood pressure (BP), like all biological variables, varies widely in different people and, in the same individual, at different times of the day. There are many more ways to obtain inaccurate results such as trying to obtain a measurement in a noisy environment, not supporting the arm at the correct level, wrong definition of systole or diastole, not pumping high enough, releasing the pressure too rapidly, too much (or even too little) finger pressure on the stethoscope, manometer not at eye level, hand not palm up. The point is that it is easy to obtain an inaccurate measurement without realizing it, and a correct measurement is only obtained with a great deal of attention being paid to every detail This attention is seldom present in a clinical environment [3]. If the measurement is erroneously low, for example, the patient may be denied the most valuable drug treatment to prevent future stroke and heart attack, whereas if, on the other hand, the

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