How is LVIDdn calculated in the Echo Calculator?

LVIDdn (normalized Left Ventricular Internal Diameter in diastole) is calculated using the Cornell allometric scaling formula: LVIDd (cm) / Weight (kg)^0.294. A value > 1.7 is typically considered indicative of left ventricular enlargement.

What are the EPIC trial criteria for Stage B2 MMVD?

The EPIC trial defines Stage B2 as a patient with a murmur grade > 3/6 and echocardiographic evidence of cardiomegaly, specifically an LA:Ao ratio > 1.6 and an LVIDdn > 1.7.

Should I use breed-specific normals or Cornell scaling?

Standard Cornell scaling is appropriate for most breeds. However, for 'deviant' breeds like Sighthounds or Boxers, published breed-specific reference intervals should be used to avoid mis-staging heart disease.

Should I use LA:Ao or LAD?

The LA:Ao ratio measurement has been the gold standard metric for assessing left atrial size, but has been shown to be challenging to measure reliably especially in inexperienced hands. Moving towards the LAD (left atrial diameter in long axis) is now recommended, and can be scaled to body weight using the allometric scaling formula LAD (cm) / Weight (kg)^0.309. A value > 1.6 is typically considered indicative of left atrial enlargement.

VetCardioHub EchoCalc

Echo Calculator

Enter your echo measurements here to calculate normalised values and see reference ranges.

Enter measurements in mm and weight in kg.

Body Weight (kg)

Species/Breed Reference Model:

LV Measurements:

LVIDd (mm)

LVIDs (mm)

IVSd (mm)

LVPWd (mm)

LVEDV modified Simpsons (ml)

LVESV modified Simpsons (ml)

LA Measurements:

LA short-axis (mm)

Ao Diameter (mm)

LA Long Axis (LAD) (mm)

Echocardiography Report

Weight: kg | BSA: m² | Model:

Left Ventricle:

LVIDd mm (Enlarged) (Small) (Normal)

LVIDs mm

IVSd mm (Thickened) (Normal)

LVFWd mm (Thickened) (Normal)

Fractional Shortening % (Normal) (Abnormal) (ref >25)

Ejection Fraction % (Normal) (Abnormal) (ref >50)

LVIDDN (Cornell) (Enlarged) (Borderline Enlarged) (Normal) (Underfilled) (ref 1.27 - 1.7)

LVIDSN (Cornell) (Enlarged) (Normal) (Underfilled) (ref 0.71 - 1.26)

Relative Wall Thickness (Thick Walls) (Normal Walls) (Thin Walls) (ref 0.32-0.42)

LVEDV / BW (Enlarged) (Normal) (Underfilled) (ref 1.25 - 3.00)

LVESV / BW (Enlarged) (Normal) (Underfilled) (ref 0.3 - 1.35)

LVEDV / m² (Normal) (Enlarged) ml/m² (ref <100)

LVESV / m² (Enlarged) ml/m² (ref <30)

Left Atrium:

LA mm

Ao mm

LAD (Long Axis) mm

LA:Ao Ratio (Enlarged) (Normal) (ref <1.65)

LA (short axis) Normalised (Enlarged) (Normal) (ref <1.17)

LAD : Ao(short axis) (Enlarged) (Normal) (ref <2.1)

LADN (Enlarged) (Normal) (ref <1.6)

Clinical Observations & Plan:

Report Copied to Clipboard!

Canine EPIC Check

(Applicable to Degenerative Mitral Valve Disease cases only)

Left Atrial Enlargement (LA:Ao > 1.65) - Very Enlarged Slightly Enlarged - Check LAD Normal Awaiting measurements...

LV Enlargement (LVIDDN > 1.7) - Very Enlarged Slightly Enlarged - Check Breed Normal Normal Awaiting measurements...

EPIC - Meets Echo Criteria for Stage B2 Does Not Meet Criteria Awaiting measurements...

⚠️ Stage B2 Potential

This patient meets the EPIC Trial echo criteria for Stage B2. In the presence of a grade ≥3/6 murmur, pimobendan may be indicated.

💡 Clinical Nuance: The EPIC trial uses a threshold of >1.70 for LVIDdn to define cardiomegaly. This is more sensitive than the statistical 95% limit (1.85) to ensure at-risk patients aren't missed. 5% of dogs will have normal hearts > 1.7 and especially athletic/sighthound breeds.

Feline Risk Assessment

(ISCAID / HCM Screening Guidelines)

HCM Phenotype (Wall ≥ 6mm):

ATE / Thrombus Risk:

Severe LA Enlargement: High risk of ATE. Recommend Clopidogrel and screening for "smoke" or thrombus.

Moderate LA Enlargement: Risk of thrombus formation present. Clinical monitoring and consideration of antiplatelet therapy indicated.

Is your patient a breed with recorded echo normals?

Select a breed to compare patient results with published breed-specific intervals.

Allometric Prediction Tool

Patient Weight (kg):

Dataset Selection:

Awaiting Weight Entry
Reference ranges will appear once a weight is entered.

Current Weight: kg | Reference:

Metric	Patient	Mean	95% Range (mm)

Dataset Note:

Parameter	Formula (Normalised)	Limit
LVIDdn	$$\frac{LVIDd}{Wt^{0.294}}$$	<1.7
LAsaxn	$$\frac{LA}{Wt^{0.355}}$$	<1.17
LADn	$$\frac{LAD}{Wt^{0.309}}$$	<1.6