Skip to content
How It Works
Explore
Resources Ask a Question
Who It's For
Patients
Decode results, prep for appointments, weigh options.
Caregivers & advocates
Carry the research load for someone you love.
Providers & clinicians
Resources for patients in your practice.
Log In Ask a Question
PubMed This is a summary of 19 peer-reviewed journal articles Updated
Pediatric Cardiology

Deciphering the Report: Interpreting Echocardiograms and Z-Scores

At a Glance

In Hypoplastic Right Heart Syndrome, echocardiogram Z-scores measure how underdeveloped heart structures are compared to a healthy child. The tricuspid valve annulus Z-score is a critical metric that helps cardiologists determine whether your child needs a biventricular repair or a single-ventricle pathway.

When you first see an echocardiogram (ultrasound of the heart) report for Hypoplastic Right Heart Syndrome (HRHS), it can look like a wall of technical jargon and numbers. However, these specific metrics are the “ruler” doctors use to determine which surgical path is safest for your child. Understanding a few key terms can help you move from feeling overwhelmed to feeling empowered during medical discussions [1][2].

The Power of the Z-Score

In pediatric cardiology, a Z-score is a way of measuring how much a heart structure differs from what is “normal” for a child of that specific height, weight, and age [2][3].

  • 0 is the average size for a healthy child.
  • -2 or lower often indicates that a structure is significantly hypoplastic (underdeveloped) [2][4].

For children with HRHS, the Tricuspid Valve Annulus Z-score is one of the most critical numbers. The annulus is the fibrous ring that supports the heart valve [5].

  • Z-score > -2: Usually suggests the right ventricle is large enough to eventually pump blood to the lungs on its own (Biventricular Repair) [6][7].
  • Z-score < -4: Typically suggests the right ventricle is too small to function as a main pump, often leading to the Single-Ventricle (Fontan) pathway [8][1].
  • The “Gray Zone” (-2 to -4): If your child’s score falls in this range, doctors will look at other factors like the shape of the ventricle and the presence of abnormal blood vessels to decide the best path [8][1].

Key Technical Terms Explained

  • Tripartite vs. Bipartite: A healthy right ventricle has three parts (inlet, apex, and outlet). If it is tripartite, it has all three and is more likely to grow. If it is bipartite, it is missing one part (usually the outlet), making a full repair more challenging [9][1].
  • Gradient: This measures the pressure difference across a valve (like the pulmonary valve). A high gradient means the valve is very narrow, and the heart is working harder to push blood through it [10][11].
  • Fistulae (or Sinusoids): These are abnormal “shortcuts” or connections between the heart chambers and the coronary arteries that feed the heart muscle [12][13].
  • Atresia: This means a valve or opening is completely missing or blocked (e.g., Pulmonary Atresia) [1][14].
  • Regurgitation (TR): This is “leaking” or backward flow through a valve. In HRHS, the amount of Tricuspid Regurgitation can help doctors predict how well the right ventricle might grow [15][16].

Echo Completeness Checklist

You have the right to ask your care team if these specific data points are included in your child’s report. These are the “must-haves” for planning your child’s future [1][17]:

  • [ ] Tricuspid Valve Annulus Z-score (How small is the “door” to the right ventricle?)
  • [ ] RV Morphology (Is the ventricle tripartite, bipartite, or severely diminutive?)
  • [ ] Presence of RVDCC (Has Right Ventricle-Dependent Coronary Circulation been ruled out?)
  • [ ] Coronary-Cameral Fistulae (Are there abnormal connections to the heart’s own blood supply?)
  • [ ] TV/MV Ratio (The size ratio between the tricuspid and mitral valves, which helps predict repair success) [16].

While the numbers provide a roadmap, they are not the whole story. Your child’s medical team will use these scores alongside clinical observations to create an individualized plan [18][19]. If a data point is missing or you don’t understand a metric, don’t hesitate to ask—being informed is your best tool for advocacy.

Common questions in this guide

What does a Z-score mean on an echocardiogram?
A Z-score measures how much a specific heart structure differs from the average size for a healthy child of the same height, weight, and age. A score of 0 is average, while scores of -2 or lower usually indicate the structure is underdeveloped.
Why is the tricuspid valve annulus Z-score important in HRHS?
This measurement helps doctors determine if your child's right ventricle is large enough to pump blood on its own. A score greater than -2 often suggests a two-ventricle repair is possible, while a score lower than -4 typically leads to a single-ventricle pathway.
What is the difference between a tripartite and bipartite right ventricle?
A healthy right ventricle has three parts (inlet, apex, and outlet) and is called tripartite. If it is missing one of these parts, it is called bipartite, which makes a full biventricular repair more challenging.
What are coronary-cameral fistulae or sinusoids?
These are abnormal connections or 'shortcuts' between the heart chambers and the coronary arteries that supply blood to the heart muscle. Their presence can significantly affect the surgical plan for your child.

Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.What is the exact Z-score of my child's tricuspid valve annulus?
  2. 2.Does the echo report describe the right ventricle as 'tripartite' or 'bipartite'?
  3. 3.Are 'coronary-cameral fistulae' or 'sinusoids' mentioned on the report, and what does that mean for our surgical plan?
  4. 4.Was Right Ventricle-Dependent Coronary Circulation (RVDCC) ruled out, and which imaging test was used to confirm this?
  5. 5.If the tricuspid valve Z-score is in the 'gray zone' (between -2 and -4), what other factors are you using to decide on the surgical pathway?

Questions For You

Tap a prompt to share your answer — we'll use it plus this page's context to start a tailored conversation.

References

References (19)
  1. 1

    Pulmonary Atresia With Intact Ventricular Septum With Borderline Tricuspid Valve: How Small Is Too Small.

    LaPar DJ, Bacha E

    Seminars in thoracic and cardiovascular surgery. Pediatric cardiac surgery annual 2019; (22()):27-31 doi:10.1053/j.pcsu.2019.02.007.

    PMID: 31027561
  2. 2

    Alternative to Body Surface Area as a Solution to Correct Systematic Bias in Pediatric Echocardiography z Scores.

    Plante V, Gobeil L, Xiong WT, et al.

    The Canadian journal of cardiology 2021; (37(11)):1790-1797 doi:10.1016/j.cjca.2021.06.017.

    PMID: 34216742
  3. 3

    The Early "Unnatural" History Following Surgical Repair of Ventricular Septal Defects.

    Chikkabyrappa SM, Tretter JT, Doshi AR, et al.

    Kansas journal of medicine 2019; (12(4)):121-124.

    PMID: 31803353
  4. 4

    Fetal growth of left-sided structures and postnatal surgical outcome in borderline left heart varies by cardiac phenotype.

    Venardos A, Colquitt J, Morris SA

    Ultrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology 2022; (59(5)):642-650 doi:10.1002/uog.23689.

    PMID: 33998097
  5. 5

    Predictors of successful pulmonary valve-sparing repair in pediatric humanitarian patients with Tetralogy of Fallot.

    Mendes V, Mouloudi A, Jolou J, et al.

    Journal of cardiothoracic surgery 2025; (20(1)):243 doi:10.1186/s13019-025-03475-x.

    PMID: 40437592
  6. 6

    Optimal Z-Score Use in Surgical Decision-Making in Pulmonary Atresia With Intact Ventricular Septum.

    Awori MN, Mehta NP, Mitema FO, Kebba N

    World journal for pediatric & congenital heart surgery 2017; (8(3)):385-388 doi:10.1177/2150135117701407.

    PMID: 28520535
  7. 7

    Outcomes of Radiofrequency Perforation for Pulmonary Atresia and Intact Ventricular Septum: A Single-Centre Experience.

    Rathgeber S, Auld B, Duncombe S, et al.

    Pediatric cardiology 2017; (38(1)):170-175 doi:10.1007/s00246-016-1498-0.

    PMID: 27837307
  8. 8

    Pulmonary Atresia with Intact Ventricular Septum: Correlation of Preoperative Computed Tomography-Derived Parameters with Echocardiographic Tricuspid Valve Z-Score and Surgical Outcomes.

    Goo HW, Park SH, Goo SY

    Pediatric cardiology 2025; (46(6)):1560-1569 doi:10.1007/s00246-024-03570-1.

    PMID: 38953951
  9. 9

    Echocardiographic Assessment of Cardiac Phenotype Predicts Complications and Guides Intensive Care Management Following Pulmonary Valve Balloon Dilation in Neonates With Pulmonary Atresia/Critical Pulmonary Stenosis With Intact Ventricular Septum.

    Moras P, Luciano P, Campanale CM, et al.

    Echocardiography (Mount Kisco, N.Y.) 2025; (42(5)):e70182 doi:10.1111/echo.70182.

    PMID: 40367357
  10. 10

    Value of pulmonary annulus area index in predicting transannular patch placement in tetralogy of Fallot repair.

    Zhao J, Cai X, Teng Y, et al.

    Journal of cardiac surgery 2020; (35(1)):48-53 doi:10.1111/jocs.14321.

    PMID: 31899832
  11. 11

    Preserving the pulmonary valve in Tetralogy of Fallot repair: Reconsidering the indication for valve-sparing.

    Siddiqi U, Adewale A, Pena E, et al.

    Journal of cardiac surgery 2022; (37(12)):5144-5152 doi:10.1111/jocs.17156.

    PMID: 36378940
  12. 12

    Coronary artery fistula.

    Vaidya YP, Green GR

    Journal of cardiac surgery 2019; (34(12)):1608-1616 doi:10.1111/jocs.14267.

    PMID: 31557360
  13. 13

    A rare case of dual coronary cameral fistulae.

    Ozgur SS, Shamoon Y, Abboud R, et al.

    Clinical case reports 2023; (11(12)):e8300 doi:10.1002/ccr3.8300.

    PMID: 38084354
  14. 14

    Is there a transcatheter solution for a sick neonate with hypoplastic right heart syndrome?: Pulmonary valve perforation in a neonate with hypoplastic right ventricle with pulmonary atresia, restrictive VSD-a case report.

    Barwad P, Prasad K, Vijay J, Naganur S

    The Egyptian heart journal : (EHJ) : official bulletin of the Egyptian Society of Cardiology 2020; (72(1)):64 doi:10.1186/s43044-020-00097-7.

    PMID: 32990873
  15. 15

    Outcomes After Decompression of the Right Ventricle in Infants With Pulmonary Atresia With Intact Ventricular Septum Are Associated With Degree of Tricuspid Regurgitation: Results From the Congenital Catheterization Research Collaborative.

    Petit CJ, Glatz AC, Qureshi AM, et al.

    Circulation. Cardiovascular interventions 2017; (10(5)) doi:10.1161/CIRCINTERVENTIONS.116.004428.

    PMID: 28500137
  16. 16

    Echocardiographic predictors of surgical outcomes in pulmonary atresia with intact ventricular septum and development of a discriminatory calculator: an Australian tertiary institution experience.

    Justo E, Tarca A, McKinnon E, et al.

    Cardiology in the young 2025; (35(2)):350-357 doi:10.1017/S1047951124036205.

    PMID: 39780473
  17. 17

    Pulmonary atresia with intact ventricular septum: Intended strategies.

    Sukhavasi A, McHugh-Grant S, Glatz AC, et al.

    The Journal of thoracic and cardiovascular surgery 2022; (164(5)):1277-1288 doi:10.1016/j.jtcvs.2021.11.104.

    PMID: 35414413
  18. 18

    Neonatal Pulmonary Atresia With Intact Ventricular Septum-8-Year Surgical Experience at One Center.

    Guanhua L, Jianzheng C, Gang X, et al.

    The Journal of surgical research 2020; (251()):38-46 doi:10.1016/j.jss.2020.01.017.

    PMID: 32113036
  19. 19

    A case report of pulmonary atresia with intact ventricular septum: an extraordinary finding of subsystemic right ventricle.

    Luo G, Liu A, Sun H, et al.

    Frontiers in pediatrics 2024; (12()):1251274 doi:10.3389/fped.2024.1251274.

    PMID: 38751746

This page explains HRHS echocardiogram terminology for educational purposes. Your pediatric cardiologist is the best source for interpreting your child's specific imaging results.

Get notified when new evidence is published on Hypoplastic right heart syndrome.

We monitor PubMed for new peer-reviewed studies on this topic and email a short summary when something meaningful changes.