Carotid Artery Applanation Tonometry Does Not Cause Significant Baroreceptor Activation

Area of Science:

• Cardiovascular Physiology
• Hypertension Research
• Biomedical Engineering

Background:

• Carotid artery applanation tonometry is crucial for assessing carotid artery pressure and pulse wave velocity.
• Potential baroreceptor reflex activation by tonometry may alter hemodynamics during sequential measurements.
• This could introduce errors in combined carotid-femoral pulse wave velocity calculations.

Purpose of the Study:

• To investigate the influence of carotid artery applanation tonometry on heart rate and blood pressure.
• To determine if tonometry induces a baroreceptor response affecting hemodynamic measurements.

Main Methods:

• Continuous finger pulse waveform recording was used to assess heart rate and blood pressure in 26 hypertensive subjects.
• Measurements were taken during both carotid and femoral applanation tonometry, alternating and in triplicate.
• Median averaging was applied to obtain representative hemodynamic values for each tonometry site.

Main Results:

• No statistically significant differences were observed in heart rate or systolic, diastolic, and pulse blood pressure between carotid and femoral tonometry.
• The maximum absolute difference at 95% certainty was 1.6 bpm for heart rate and less than or equal to 3.5 mm Hg for blood pressures.

Conclusions:

• Carotid artery applanation tonometry, when performed by an experienced researcher, did not induce clinically significant baroreceptor activation.
• The findings support the validity of sequential tonometry measurements for pulse wave velocity assessment.