Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2002 Jul;88(1):76-80.
doi: 10.1136/heart.88.1.76.

A new, simple, and accurate method for non-invasive estimation of pulmonary arterial pressure

Affiliations

A new, simple, and accurate method for non-invasive estimation of pulmonary arterial pressure

J Xu et al. Heart. 2002 Jul.

Abstract

Objective: To develop and validate a new non-invasive method for the estimation of pulmonary arterial pressure (PAP) based on advanced signal processing of the second heart sound.

Design: Prospective comparative study.

Setting: Referral cardiology centre.

Patients: This method was first tested in 16 pigs with experimentally induced pulmonary hypertension and then in 23 patients undergoing pulmonary artery catheterisation.

Methods: The heart sounds were recorded at the surface of the thorax using a microphone connected to a personal computer. The splitting time interval between the aortic and the pulmonary components of the second heart sound was measured using a computer assisted spectral dechirping method and was normalised for heart rate.

Results: The systolic PAP varied between 14-73 mm Hg in pigs and between 20-70 mm Hg in patients. The normalised splitting interval was measurable in 97% of the recordings made in pigs and 91% of the recordings made in patients. There was a strong relation between the normalised splitting interval and the systolic PAP (pigs: r = 0.94, standard error of the estimate (SEE) = 5.3 mm Hg; patients: r = 0.84, SEE = 7.8 mm Hg) or the mean pulmonary pressure (pigs: r = 0.94, SEE = 4.1 mm Hg; patients: r = 0.85, SEE = 5.8 mm Hg).

Conclusions: This study shows that this new non-invasive method based on advanced signal processing of the second heart sound provides an accurate estimation of the PAP.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Schematic representation of the acoustic system used to estimate pulmonary arterial pressure. PCG, phonocardiogram.
Figure 2
Figure 2
Method for the estimation of the splitting interval (SI) between the aortic (A2) and pulmonary (P2) components of the second heart sound (S2). (A) The original S2 signal in the time domain. (B) A2 and P2 components detected and reconstructed using a spectral dechirping approach. (C) Measurement of SI on the cross correlation function (CCF) between A2 and P2. In panels A and B, time zero is a relative temporal reference corresponding to the beginning of the 100 ms temporal window containing S2; in panel C, time zero corresponds to the onset of A2, as shown in panel B.
Figure 3
Figure 3
Relation between the normalised A2-P2 splitting time interval (NSI) and the systolic (A) or mean (B) PAP in pigs.
Figure 4
Figure 4
Relation between the NSI and the systolic (A) or mean (B) PAP in patients.

References

    1. Yock PG, Popp RL. Noninvasive estimation of right ventricular systolic pressure by Doppler ultrasound in patients with tricuspid regurgitation. Circulation 1984;70:657–62. - PubMed
    1. Currie PJ, Seward JB, Chan KL, et al. Continuous wave Doppler determination of right ventricular pressure: a simultaneous Doppler-catheterization study in 127 patients. J Am Coll Cardiol 1985;6:750–6. - PubMed
    1. Naeije R, Torbicki A. More on the noninvasive diagnosis of pulmonary hypertension: Doppler echocardiography revisited. Eur Respir J 1995;8:1445–9. - PubMed
    1. Nishimura RA, Tajik AJ. Quantitative hemodynamics by Doppler echocardiography: a noninvasive alternative to cardiac catheterization. Prog Cardiovasc Dis 1994;36:309–42. - PubMed
    1. Leatham A. Auscultation of the heart and phonocardiography. New York: Churchill Livingstone, 1975:1–178.

Publication types

MeSH terms