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The VetCardioHub Echo Calculator: A Clinical Workflow Guide

Performing a diagnostic echocardiogram is only half the battle. The other half is sitting at a computer translating those raw measurements into actionable clinical staging. From my very first experiences of echo, I soon realised that great technique needed to be backed up by skilled interpretation and judgement. The magic of echo though is that so much can be quantified. But how to know what is normal and what the numbers mean clinically?

There are now so many things to measure and many ways of assessing what is normal and what isn’t.

The VetCardioHub Echo Calculator was built to eliminate the manual maths and cross-referencing required to answer these questions. This guide outlines how to utilize the advanced features of the calculator to streamline your clinical decision-making.

1. Automated Allometric Scaling & Breed-Specific Normals

Evaluating left ventricular size using fixed ranges is inaccurate due to the vast size discrepancies across canine breeds. Even in cats there is some size and breed variation that often needs consideration.

The calculator uses allometric scaling to index dimensions to body weight dynamically.

  • How it works: Input the patient’s weight and raw LVIDd / LVIDs. The calculator immediately outputs the LVIDdn and LVIDsn according to the original Cornell data. You can also use Esser’s more updated model that excluded sighthounds, or otherwise use a sighthound model, puppy model or cat/kitten model as appropriate to your patient.

  • Breed Adjustments: The standard model (Cornell) is appropriate for most dogs. However, if you select a specific breed from the dropdown (e.g., a Whippet or a Sphynx cat), the calculator automatically switches the underlying allometric model. It will use the Stepien Sighthound references or the Karsten Adult Feline references to prevent false-positive diagnoses of cardiomegaly in athletic breeds. You can also see any published normal values specific to the breed you are working with, which is particularly important with the various breeds that tend to have different sized hearts to normal.

  • Clinical Application: You can instantly confirm if a patient meets the LVIDdn ≥ 1.7 and LA:Ao ≥ 1.6 criteria required for ACVIM Stage B2 (EPIC trial criteria) classification, with our automatic check.

2. Diastolic Function Profiling

Diastolic dysfunction is one of the earliest markers of heart disease, but interpreting the various flow velocities can be intimidating. The calculator includes a Diastolic Scorer that evaluates the interplay of multiple parameters.

  • How it works: Input your spectral Doppler findings (E wave, A wave, IVRT, E’, etc.).
  • The Logic: The calculator acts as a conflict checker. It analyzes the inputs to determine if the patient fits a specific pattern of relaxation abnormality:
  • Grade I (Impaired Relaxation): E:A reversal, prolonged IVRT. Indicates stiffening but normal filling pressures.
  • Grade II (Pseudonormal): Normal-appearing E:A, but elevated E:E’. Indicates rising left atrial pressures (LAP) masking the relaxation defect.
  • Grade III (Restrictive): Tall E wave, tiny A wave, short IVRT. Indicates severe elevation in LAP and high risk of acute congestive heart failure.
  • Confidence Scoring: If your inputs contradict each other (e.g., a restrictive E:A ratio but a normal E:E’), the calculator flags a “Mixed Profile” so you know to re-evaluate your images or consider the clinical context carefully.

3. ACVIM Pulmonary Hypertension (PHT) Probability Algorithm

Diagnosing pulmonary hypertension requires looking beyond just the tricuspid regurgitation (TR) velocity, especially when TR is absent or unmeasurable. The calculator automates the 2020 ACVIM consensus guidelines for determining PHT probability.

  • How it works: The calculator tracks abnormalities across three distinct anatomic sites:
  1. Site 1 (Ventricles): Septal flattening (LVEI ≥ 1.2), RV wall thickening.
  2. Site 2 (Pulmonary Artery): Enlarged MPA:Ao ratio, abnormal PR velocity.
  3. Site 3 (Right Atrium & RV Size): Enlarged RAD or RV dimensions based on right-heart allometric models.
  • The Matrix: If TR is moderate (2.9 - 3.4 m/s), the algorithm checks how many anatomic sites show abnormalities. If ≥ 2 sites are abnormal, the probability is upgraded to “High.”
  • The Chang 2026 Predictive Score: For dogs lacking measurable TR, the calculator integrates the Chang 2026 scoring system. By comparing right-sided dimensions to left-sided dimensions, it generates a predictive score indicating the likelihood of severe pre-capillary PH.

4. The MINE Score for Mitral Valve Disease

For dogs with degenerative mitral valve disease, providing owners with an accurate prognosis is difficult. The calculator includes the MINE (Mitral INsufficiency Echocardiographic) score to stratify risk.

  • How it works: Input the core parameters: LA:Ao, LVIDdn, Fractional Shortening, and the Transmitral E-wave velocity.
  • Output: The calculator determines the total points and categorizes the patient’s risk tier, providing an evidence-based Median Survival Time (MST) to help guide your owner discussions. You can select whether you prefer the original scoring system, or the updated ‘MINE-2’ score published in 2025.

5. Feline Specific Features: HCM and ATE Risk

Feline echocardiography requires a different approach. When the patient species is identified as Feline (either via the breed dropdown or the text parser), specific alerts are activated.

  • Wall Thickness Alert: The calculator flags ventricular walls ≥ 6mm as consistent with a Hypertrophic Cardiomyopathy (HCM) phenotype.
  • ATE Risk Stratification: Left atrial size is a primary driver of Arterial Thromboembolism (ATE) in cats. The calculator monitors the LAD input and triggers high-risk alerts when the atrium becomes severely enlarged (≥ 20mm).
  • LVOTO Tracking: Dynamic obstruction is common in feline HCM. The calculator flags elevated outflow velocities (> 1.9 m/s) and prompts a review of the CW Doppler envelope for the classic “dagger” shape of SAM.

6. One-Click Medical Records and Clinical Audits

Writing detailed echo reports is tedious. The calculator includes two powerful export functions:

  1. The Standard Report: Click the copy button to generate a clean, formatted text summary of all your inputs, including normalized values, reference ranges, and flags for abnormal findings.
  2. The PHT Clinical Audit: If you utilize the pulmonary hypertension algorithm, you can generate a specific PHT audit. This exports the exact breakdown of which ACVIM anatomic sites were positive and the final probability matrix, providing a robust justification for your diagnostic conclusion in the patient’s record.

Tip: The Interactive Glossary

If you ever encounter a parameter you are unfamiliar with (e.g., How exactly do I measure the ePLAR?), simply click on the parameter icon in the calculator. This will open the interactive clinical dictionary, providing the optimal imaging view, the methodology, and the clinical utility of the measurement without requiring you to leave the page.

Take a look right here:VetCardioHub EchoCalc