Abstract

Introduction

Materials & Methods

Results

Discussion & Conclusion

References

Discussion
Board

BACKGROUND: Non-invasive methods of assessing haemodynamics have an increasing role to play in the understanding of cardiovascular physiology. We investigated the PORTAPRES, a portable method of measuring beat-to-beat blood pressure and cardiovascular haemodynamics and compared it with the established method of impedance cardiography (BoMED). METHODS: Mean arterial pressure (MAP), heart rate (HR) and cardiac index (CI) and systemic vascular resistence were measured in 8 healthy male subjects using the PORTAPRES and BoMED at identical time points at rest and following each stage of a seven stage graded exercise schedule. Differences between paired readings using the techniques were compared by Bland & Altman analysis. RESULTS: Although strong correlations were seen between techniques with MAP (r = 0.74) and percentage change in CI (r = 0.79), absolute measurements of MAP and CI were lower with PORTAPRES. Reproducibility at rest was excellent (within subject coefficients of variation 6.3 - 8.5%). On exercise, the percentage change from baseline was comparable for MAP 6.1 ± 17% (mean difference ± SD) and CI 6.1 ± 29%. CONCLUSION: In our study relative rather than absolute changes were best represented. Although differences in MAP represented differences in measurement site, the PORTAPRES measured CI consistently low. We conclude that the PORTAPRES is a simple and convenient tool for continuous ambulatory monitoring of MAP and CI, however, absolute values, especially of CI, are too inaccurate for its use in clinical practice.

Back to the top.
Poster Number PAmills0906
Keywords: non-invasive, blood pressure, portapres, bomed, impedance