ASECHO Use of Echocardiography in the Evaluation of Rheumatic Heart Disease Guideline Summary

Basic Concepts of Pathophysiology, Clinical Presentation, and Screening

Key Points

RHD is the long-term consequence of ARF.
Rheumatic carditis from ARF is due to immune-mediated injury to the heart following group A β-hemolytic streptococcus (S. pyogenes) infection, with antibodies developed in response to streptococcal pharyngitis subsequently cross-reacting with cardiac proteins in a susceptible host.
Valvulitis is the most consistent feature of rheumatic carditis and commonly associated with mitral or aortic valve regurgitation.
Echocardiographic evidence of valvulitis is a major criterion in the diagnosis of subclinical carditis.

Recommendations

More than trace AR or MR in children should be considered pathological and may indicate rheumatic carditis or RHD, provided non-rheumatic causes are excluded.
Pathological valvular regurgitation suggesting carditis should include pansystolic MR or pandiastolic AR seen in more than 1 view with peak velocity >3 m/s in at-risk populations.
Measurement of valve thickness should be performed with tissue harmonics turned off as this modality increases apparent tissue thickness.

Key Points:

Rheumatic MS is defined by a transmitral mean pressure gradient >4 mmHg and typical morphological changes in the valve consistent with a rheumatic process: thickened mitral leaflets, commissural fusion, restricted MV leaflet motion, diastolic doming of the anterior mitral leaflet, and/or chordal thickening/calcification.
Severe rheumatic MS is indicated by MVA ≤1.5 cm2, PHT ≥150 msec, and transmitral mean gradient ≥10 mmHg.

Recommendations:

MS should be evaluated in a comprehensive approach, including a careful examination of valve morphology with 2DE, accurate determination of MVA by planimetry at the level of the leaflet tips, with 3DE multiplanar guidance if needed, hemodynamic assessment with Doppler echocardiography to determine PHT and mean pressure gradient, and supportive data, such as pulmonary artery pressure estimation and left atrial size.
Planimetry is the preferred method for determination of anatomic MVA. The imaging plane should be positioned at the leaflet tips, and the smallest orifice area should be traced in zoom mode, with an optimized gain setting to avoid signal “drop-out”.
Excessive gain, which can result in MVA underestimation, should be avoided.
The cardiac rhythm and heart rate should be noted as part of Doppler assessment of MS.
When the CWD spectral pattern of mitral inflow is bimodal with an initial rapid deceleration followed by a slower rate of decline, the linear portion of the mid-diastolic slope should be traced for PHT, rather than using the early steep deceleration slope.
Stress echocardiography should be considered in patients whose symptoms are incongruent with echocardiographic data and for risk stratification of patients with MS. A transmitral mean gradient >15 mmHg during exercise echocardiography (or ≥18 mmHg during dobutamine echocardiography) should be considered hemodynamically significant rheumatic MS and identifies patients who might benefit from intervention.

Use of Echocardiography in the Evaluation of Rheumatic Heart Disease