Relationship between ventilatory thresholds and systolic blood pressure variability

Area of Science:

• Exercise Physiology
• Cardiovascular Regulation
• Biomedical Engineering

Background:

• Exercise increases respiratory rate, amplifying blood pressure oscillations, especially beyond ventilatory thresholds (VTs).
• Systolic blood pressure variability (SBPV) may offer an alternative method for assessing these physiological changes during exercise.

Purpose of the Study:

• To investigate the feasibility of determining blood pressure ventilatory thresholds (BPVTs) from SBPV analysis during incremental exercise.
• To compare BPVTs derived from SBPV with traditional ventilatory thresholds (VTs).

Main Methods:

• Fifteen well-trained subjects underwent an incremental exhaustive exercise test on a cycloergometer.
• Blood pressure, ECG, and ventilatory equivalents (VE/VO2, VE/VCO2) were recorded.
• Short-Time Fourier Transform analyzed SBP series for instantaneous high-frequency SBPV (HF-SBPV) to determine BPVTs.

Main Results:

• BPVTs were successfully determined in 12 out of 15 subjects.
• No statistically significant differences were found between VT1 and BPVT1, or VT2 and BPVT2.
• BPVT1 showed a slight underestimation, while BPVT2 showed a slight overestimation compared to VTs, with specific limits of agreement.

Conclusions:

• BPVT determination from SBPV analysis is a viable method, particularly for sedentary or pathological populations.
• This method may not be as accurate for well-trained individuals due to potential over/underestimations.
• Further research could refine BPVT assessment for diverse populations.