Observational Study
Copyright ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Cardiol. Aug 26, 2017; 9(8): 693-701
Published online Aug 26, 2017. doi: 10.4330/wjc.v9.i8.693
Estimating pressure gradients by auscultation: How technology (echocardiography) can help improve clinical skills
Rohini L Kadle, Colin K L Phoon
Rohini L Kadle, Colin K L Phoon, Division of Pediatric Cardiology, Hassenfeld Children’s Hospital of New York at NYU Langone, Fink Children’s Center, New York, NY 10016, United States
Author contributions: Kadle RL assisted in data analysis and contributed extensively to the writing of the manuscript; Phoon CKL designed the research, performed the research, analyzed the data, and wrote and approved the final manuscript.
Institutional review board statement: This study was reviewed by the NYU School of Medicine’s Institutional Review Board (IRB).
Informed consent statement: As per the Institutional Review Board-approved protocol, no informed consent was required (and therefore none was obtained), since all data were collected anonymously and de-identified.
Conflict-of-interest statement: We report no conflicts of interest, real or perceived, financial or otherwise.
Data sharing statement: Dataset is available from the corresponding author at colin.phoon@nyumc.org. No additional data are available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Colin K L Phoon, MPhil, MD, Associate Professor of Pediatrics, Division of Pediatric Cardiology, Hassenfeld Children’s Hospital of New York at NYU Langone, Fink Children’s Center, 160 East 32nd Street, 2nd floor/L-3, New York, NY 10016, United States. colin.phoon@nyumc.org
Telephone: +1-212-2639990 Fax: +1-212-2639678
Received: November 7, 2016
Peer-review started: November 10, 2016
First decision: March 8, 2017
Revised: March 29, 2017
Accepted: May 3, 2017
Article in press: May 5, 2017
Published online: August 26, 2017
Abstract
AIM

To extend our previously-published experience in estimating pressure gradients (PG) via physical examination in a large patient cohort.

METHODS

From January 1, 1997 through December 31, 2009, an attending pediatric cardiologist compared clinical examination (EXAM) with Doppler-echo (ECHO), in 1193 patients with pulmonic stenosis (PS, including tetralogy of Fallot), aortic stenosis (AS), and ventricular septal defect (VSD). EXAM PG estimates were based primarily on a murmur’s pitch, grade, and length. ECHO peak instantaneous PG was derived from the modified Bernoulli equation. Patients were 0-38.4 years old (median 4.8).

RESULTS

For all patients, EXAM correlated highly with ECHO: ECHO = 0.99 (EXAM) + 3.2 mmHg; r = +0.89; P < 0.0001. Agreement was excellent (mean difference = -2.9 ± 16.1 mmHg). In 78% of all patients, agreement between EXAM and ECHO was within 15 mmHg and within 5 mmHg in 45%. Clinical estimates of PS PG were more accurate than of AS and VSD. A palpable precordial thrill and increasing loudness of the murmur predicted higher gradients (P < 0.0001). Weight did not influence accuracy. A learning curve was evident, such that the most recent quartile of patients showed ECHO = 1.01 (EXAM) + 1.9, r = +0.92, P < 0.0001; during this time, the attending pediatric cardiologist had been > 10 years in practice.

CONCLUSION

Clinical examination can accurately estimate PG in PS, AS, or VSD. Continual correlation of clinical findings with echocardiography can lead to highly accurate diagnostic skills.

Keywords: Physical examination, Ventricular septal defect, Clinical skills, Echocardiography, Aortic stenosis, Pulmonary stenosis

Core tip: Knowing pressure gradients across valves, arteries, and ventricular septal defects is important to clinical management of patients. In a large cohort of patients, we have determined the high degree of accuracy of the physical examination against the benchmark Doppler echocardiography. We discuss this clinical approach in the context of clinical practice, technology, and healthcare costs.