Research

Arterial pressure changes monitoring with a new precordial noninvasive sensor

Tonino Bombardini¹ , Vincenzo Gemignani² , Elisabetta Bianchini² , Lucia Venneri¹ , Christina Petersen¹ , Emilio Pasanisi¹ , Lorenza Pratali¹ , Mascia Pianelli¹ , Francesco Faita² , Massimo Giannoni² , Giorgio Arpesella³ and Eugenio Picano³

¹  Department of Echocardiography Lab, Fondazione Gabriele Monasterio, Italian National Research Council, Pisa, Italy

²  Digital Signal Processing Lab (DSPLAB), Fondazione Gabriele Monasterio, Italian National Research Council, Pisa, Italy

³  Department of Surgery and Transplants, University of Bologna, Italy

author email corresponding author email

Cardiovascular Ultrasound 2008, 6:41doi:10.1186/1476-7120-6-41

Published:	21 August 2008

Abstract

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.