Quantification of peripheral and central blood pressure variability using a time-frequency method.

Area of Science:

• Cardiovascular Physiology
• Biomedical Engineering
• Signal Processing

Background:

• Systolic blood pressure variability (BPV) is linked to cardiovascular events.
• Beat-to-beat blood pressure variations arise from complex cardiovascular control systems.
• Spectral analysis of continuous arterial pressure is used to assess BPV.

Purpose of the Study:

• To estimate central aortic pressure noninvasively from finger pressure.
• To assess systolic BPV using a time-frequency method (STFT).
• To compare BPV derived from peripheral and central aortic pressure measurements.

Main Methods:

• Continuous finger arterial pressure was measured in 30 healthy subjects.
• A continuous aortic pressure signal was estimated noninvasively from finger pressure.
• Time-frequency decomposition using STFT was applied to peripheral (pSBP) and derived central (cSBP) systolic pressures.
• The ratio of low frequency to high frequency power bands (LF/HF) was computed as a marker of cardiovascular control balance.

Main Results:

• BPV assessed from finger pressure (pBPV) significantly overestimated BPV compared to central aortic pressure (cBPV) (P<0.001).
• The overestimation of pBPV was more pronounced at higher BPV levels.
• The LF/HF ratio differed between peripheral and central measurements, indicating distinct contributions of cardiovascular control systems.

Conclusions:

• Noninvasive estimation of central aortic pressure from finger pressure is feasible for BPV assessment.
• Peripheral BPV measurements may overestimate cardiovascular risk due to signal distortion.
• Accurate BPV assessment using central aortic pressure is crucial for reliable cardiovascular event risk stratification.