Related Experiment Video
Updated: Jul 2, 2026

Continuous Venous-Arterial Doppler Ultrasound During a Preload Challenge
Published on: January 20, 2023
Arterial pressure changes monitoring with a new precordial noninvasive sensor
Tonino Bombardini1, Vincenzo Gemignani, Elisabetta Bianchini
1Department of Echocardiography Lab, Fondazione Gabriele Monasterio, Italian National Research Council, Pisa, Italy. tbombardini@yahoo.it
Background:
Recently, a cutaneous force-frequency relation recording system based on first heart sound amplitude vibrations has been validated. A further application is the assessment of Second Heart Sound (S2) amplitude variations at increasing heart rates. The aim of this study was to assess the relationship between second heart sound amplitude variations at increasing heart rates and hemodynamic changes.
Methods:
The transcutaneous force sensor was positioned in the precordial region in 146 consecutive patients referred for exercise (n = 99), dipyridamole (n = 41), or pacing stress (n = 6). The curve of S2 peak amplitude variation as a function of heart rate was computed as the increment with respect to the resting value.
Results:
A consistent S2 signal was obtained in all patients. Baseline S2 was 7.2 +/- 3.3 mg, increasing to 12.7 +/- 7.7 mg at peak stress. S2 percentage increase was + 133 +/- 104% in the 99 exercise, + 2 +/- 22% in the 41 dipyridamole, and + 31 +/- 27% in the 6 pacing patients (p < 0.05). Significant determinants of S2 amplitude were blood pressure, heart rate, and cardiac index with best correlation (R = .57) for mean pressure.
Conclusion:
S2 recording quantitatively documents systemic pressure changes.
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Sites for measuring blood pressure
The Brachial Artery: Primary Site for Blood Pressure Measurement
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This invasive approach involves cannulating a peripheral artery. During each cardiac contraction, pressure generates mechanical motion within the catheter, transmitted through rigid, fluid-filled tubing to a transducer. This transducer converts mechanical motion into electrical signals displayed as waveforms on a monitor. An automatic flushing system prevents blood backflow. Due to the potential risk of unexpected arterial blood loss, this method is primarily used in intensive...
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Monitoring Both Arms:
Monitoring BP in both arms during the initial assessment is advisable, as the systolic value may differ by five to ten mm Hg between arms. For subsequent BP assessments, use the arm with the higher reading.
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Pre-Procedural Guidelines for Doppler Ultrasound Blood Pressure Assessment:
Preparation of Equipment:
Measurement of Blood Pressure
