World Heart Federation criteria for the echocardiographic diagnosis of rheumatic heart disease (RHD) in individuals aged ≤20 years. Also available as 
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Echocardiographic criteria for RHD*
Definite RHD (1, 2, 3, or 4)
- Pathologic MR and at least 2 morphologic features of RHD of the MV
- MS mean gradient ≥4 mm Hg
- Pathological AR and at least 2 morphological features of RHD of the AV
- Borderline disease of both the AV and MV
Borderline RHD (1, 2, or 3)
- At least 2 morphologic features of RHD of the MV without pathologic MR or MS
- Pathologic MR
- Pathologic AR
Echocardiographic criteria for pathologic regurgitation (all 4 Doppler criteria must be met)
Pathologic MR
- Seen in 2 views
- In at least 1 view jet length ≥2 cm†
- Peak velocity ≥3 m/s for 1 complete envelope
- Pansystolic jet in at least 1 envelope
Pathologic AR
- Seen in 2 views
- In at least 1 view jet length ≥1 cm†
- Peak velocity ≥3 m/s in early diastole
- Pandiastolic jet in at least 1 envelope
Morphologic features of RHD
Features in the MV
- AMVL thickening ≥3 mm‡
- Chordal thickening
- Restricted leaflet motion
- Excessive leaflet tip motion during systole
Features in the AV
- Irregular or focal thickening
- Coaptation defect
- Restricted leaflet motion
- Prolapse
Abbreviations: AMVL, anterior mitral valve leaflet; AR, aortic regurgitation; AV, aortic valve; MR, mitral regurgitation; MS, mitral stenosis; MV, mitral valve; and RHD indicates rheumatic heart disease.
* Congenital anomalies must be excluded.
† A regurgitant jet length should be measured from the vena contracta to the last pixel of regurgitant color (blue or red) on non-magnified (non-zoomed) images.
‡ AMVL thickness should be measured during diastole at full excursion. Measurement should be taken at the thickest portion of the leaflet and should be performed on a frame with maximal separation of chordae from the leaflet tissue.