Normative values

NeoCardioLab Data Extraction Atlas

English - At the NeoCardioLab, our commitment to transparency in our research procedures is paramount. Therefore, we are openly sharing our data extraction and echocardiography measurement methodologies for all our research projects, and our targeted neonatal echocardiography. These measurements are designed to align with the established literature and adhere to the guidelines set forth by the American Society of Echocardiography and the Canadian Society of Echocardiography. The NeoCardioLab Atlas of measurements is now available here.

Français - Au NeoCardioLab, notre engagement envers la transparence dans nos procédures de recherche est primordial. C'est pourquoi nous partageons ouvertement nos méthodes d'extraction de données et de mesure en échocardiographie pour l'ensemble de nos projets de recherche, y compris pour nos échocardiographies néonatales ciblées. Ces mesures sont conçues pour être en accord avec la littérature établie et conformes aux directives énoncées par la Société américaine d'échocardiographie et la Société canadienne d'échocardiographie. L'Atlas des mesures du NeoCardioLab est désormais disponible ici.

Pediatric Echocardiography Learning by Texas Children's Hospital

A great resources for learning - https://pedecho.org/

TAPSE Z-Score Calculator Reference Values for Right Ventricular Systolic Function

Click here for the Z-Score calculator

Parameterz links

Z-score for pediatric measurements

https://www.rchsd.org/zscore/ 

http://www.parameterz.com/

http://parameterz.blogspot.com/ 

Classification of left ventricular systolic function

Tissot C, Singh Y, Sekarski N. Echocardiographic Evaluation of Ventricular Function-For the Neonatologist and Pediatric Intensivist. Front Pediatr. 2018 Apr 4;6:79. doi: 10.3389/fped.2018.00079. PMID: 29670871; PMCID: PMC5893826.

This article classifies left ventricular function based on LV-EF in pediatric:

• Normal LV systolic function (EF ≥ 55%), 

• Mild LV systolic dysfunction (EF 41–55%), 

• Moderate LV systolic dysfunction (EF 31–40%),

• Severe LV systolic dysfunction (EF ≤ 30%)

• LV-EF is based on estimation of End Diastolic and End Systolic volumes of the LV. These may be estimated using various methods (link to outside great article): Simpson's Biplane Method, Simpson's Disc method only applied to one of the apical views, 5/6 Area-Length Bullet Method, 3D echocardiography using Speckle-Tracking Echocardiography, 2D estimation using Speckle-Tracking Echocardiography, Teichholz formula from linear dimensions (discouraged).

Tissot et al. also provides normal and abnormal values based on shortening fraction (SF). SF (same as fractional shortening - FS) can be obtained from the M-Mode at the tip of the mitral valve in the parasternal long or short axis view. The LV end diastolic and end systolic diameters can also be obtained from the B-Mode obtained in the same view. The use of this measurement is discouraged by the recent guidelines of the American Society of Echocardiography.

• Normal values in pediatric: 28 and 46%. 

• Normal LV systolic function (SF 26–45%), 

• Mild LV systolic dysfunction (SF 20–25%), 

• Moderate LV systolic dysfunction (SF 15–19%), 

• Severe LV systolic dysfunction (SF ≤14%).

Caveat about shortening fraction: relies on 2 point in the LV and many guidelines recommend against its use in comprehensive evaluation of the LV considering the tendency to have dyskenesis of the LV that may not be homogenous, as well as the septal flattening often found in the context of high PVR due to the transitional period of the newborn. The American Society of Echocardiography mentions: "Fractional Shortening (use is discouraged)" - complete article here.

As per the American College of Cardiology (ACC), mostly geared at adult functional classification but applied often in pediatric: 

• Hyperdynamic left ventricle = LV-Ejection Fraction (EF) greater than 70% 

• Normal LV systolic function -= LVEF 50% to 70% (midpoint 60%) 

• Mild LV systolic dysfunction = LV-EF 40% to 49% (midpoint 45%) 

• Moderate LV systolic dysfunction = LV-EF 30% to 39% (midpoint 35%) 

• Severe LV systolic dysfunction = LV-EF less than 30%.

As per the American College of Cardiology, in adults, there is the context of heart failure (HF) with reduced ejection fraction (HFrEF) and HF with preserved EF (HFpEF).

"Heart failure (HF) encompasses a broad range of left ventricular (LV) function. New treatment guidelines address the entire spectrum of HF. The classification of HF is as follows: 

• HFrEF (HF with reduced ejection fraction [EF]): LVEF ≤40%; 

• HFimpEF (HF with improved EF): Previous LVEF ≤40% and follow-up measurement of LVEF >40%; 

• HFmrEF (HF with mildly reduced EF): LVEF 41-49%; 

• HFpEF (HF with preserved EF): LVEF ≥50%."

Other methods to evaluate LV systolic function include: 

• Deformation analysis using speckle-tracking echocardiography

• dp/dT of the mitral insufficiency jet (particularly useful in the context of distorted LV architecture - such as in single LV physiology)

• Estimation of LV stroke distance by LVOT velocity time integral (VTI), or cardiac output (using LVOT-VTI, HR and LVOT diameter)

• Systolic velocities at the lateral and septal wall by tissue Doppler imaging.

• Fractional area change of the LV from the Apical view (similar to the RV-FAC, but applied to the LV (particularly useful in the context of distorted LV architecture - such as in single LV physiology).

There is a great table for Diastolic Function by ECGWaves - Please visit their fantastic website!

Neonatal (term) right ventricular dimensions and function in the transitional period: Normative Data and Z-Scores

Jain A, Mohamed A, El-Khuffash A, Connelly KA, Dallaire F, Jankov RP, McNamara PJ, Mertens L. A comprehensive echocardiographic protocol for assessing neonatal right ventricular dimensions and function in the transitional period: normative data and z scores. J Am Soc Echocardiogr. 2014 Dec;27(12):1293-304. doi: 10.1016/j.echo.2014.08.018. Epub 2014 Sep 23. PMID: 25260435.

How to measure eccentricity index and systolic-diastolic time ratio

From: McCrary A, Malowitz J, Hornick C, Hill K, Cotten C, Tatum G, et al. Differences in Eccentricity Index and Systolic-Diastolic Ratio in Extremely Low-Birth-Weight Infants with Bronchopulmonary Dysplasia at Risk of Pulmonary Hypertension. American journal of perinatology. 2015.

The TnECHO Rotunda Manual

Exceptional publication by Dr Afif El-Khuffash. Neonatalogist Performed Echocardiography Teaching Manual. 

Available online via the https://www.neonatalhemodynamics.com/ website - Click here. 

This publication is the sole property of Dr Afif El-Khuffash and should be used only for medical education purposes. All material contained in this publication should be referenced to the author. 

Also, available here:

Normative values for targeted neonatal echocardiography by The Rotunda Hospital, Dublin, Ireland

Available from the NHRC website

ASE Recommendations for Cardiac Chamber Quantification in Adults - Quick Reference Guide

Available here