title: Arterial pressure changes monitoring with a new precordial noninvasive sensor.
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.
  
  
  CONCLUSIONS
  S2 recording quantitatively documents systemic pressure changes.
authors: Department of Echocardiography Lab, Fondazione Gabriele Monasterio, Italian National Research Council, Pisa, Italy. tbombardini@yahoo.it
authors: Tonino
authors: T
authors: Bombardini
authors: Vincenzo
authors: V
authors: Gemignani
authors: Elisabetta
authors: E
authors: Bianchini
authors: Lucia
authors: L
authors: Venneri
authors: Christina
authors: C
authors: Petersen
authors: Emilio
authors: E
authors: Pasanisi
authors: Lorenza
authors: L
authors: Pratali
authors: Mascia
authors: M
authors: Pianelli
authors: Francesco
authors: F
authors: Faita
authors: Massimo
authors: M
authors: Giannoni
authors: Giorgio
authors: G
authors: Arpesella
authors: Eugenio
authors: E
authors: Picano
mesh_terms: D000368:Aged; D001642:Bicycling; D001794:Blood Pressure; D015924:Blood Pressure Monitors; D002304:Cardiac Pacing, Artificial; D004176:Dipyridamole; D025401:Echocardiography, Stress; D004562:Electrocardiography; D005260:Female; D006321:Heart / Q000503:physiopathology; D006339:Heart Rate; D006347:Heart Sounds; D006801:Humans; D008297:Male; D008875:Middle Aged; D013318:Stroke Volume; D016683:Supine Position; D014655:Vascular Resistance
chemical_list: D004176:Dipyridamole