2D Echocardiographic Findings in Rheumatic Heart Disease
The hallmark 2D echocardiographic findings in rheumatic heart disease include mitral valve leaflet thickening, restricted leaflet motion with the pathognomonic "hockey-stick" deformity of the anterior mitral leaflet, commissural fusion, and chordal thickening—features that distinguish rheumatic from other etiologies. 1, 2
Mitral Valve Findings (Primary Target)
The mitral valve is affected in virtually all cases of rheumatic heart disease, with 99.3% of echocardiographic cases and 100% of postmortem examinations showing mitral involvement. 1
Morphological Features
Leaflet thickening: Irregular or focal thickening of the mitral valve leaflets, particularly at the tips, is a cardinal feature that helps differentiate rheumatic from degenerative disease. 3, 2
Restricted leaflet motion with "hockey-stick" deformity: The anterior mitral leaflet demonstrates restricted mobility with characteristic diastolic doming, creating the pathognomonic "hockey-stick" appearance—this combination is virtually diagnostic of established rheumatic heart disease. 1, 2
Commissural fusion: Fusion at the commissures is a defining structural abnormality that distinguishes rheumatic mitral stenosis from degenerative mitral stenosis (which lacks commissural fusion). 3, 2, 4
Chordal thickening and fusion: Subvalvular apparatus involvement with thickened, shortened, and fused chordae tendineae is characteristic of chronic rheumatic disease. 1, 2, 4
Valvular nodules: Approximately 25% of patients with acute rheumatic carditis demonstrate focal valvular nodules on the body and tips of mitral leaflets—these likely represent echocardiographic equivalents of rheumatic verrucae and typically disappear on follow-up. 5
Functional Consequences
Mitral regurgitation: This is the most frequent finding, occurring in 87-94% of cases, with mechanisms including ventricular dilatation (54-74% of cases) and restricted leaflet mobility (37% of cases). 1, 5
Mitral stenosis: Results from the combination of commissural fusion, leaflet thickening, and restricted mobility, best assessed by 2D planimetry of the valve orifice area (though 3D planimetry provides more accurate measurements). 2, 4
Aortic Valve Findings (Secondary Target)
Morphological Features
Irregular or focal thickening: Aortic leaflet thickening occurs in 41-100% of individuals with rheumatic aortic regurgitation, commonly at the free edge of the leaflets, with higher prevalence in older patients. 3
Coaptation defect: Leaflet retraction and rolling of leaflet edges result in a characteristic central (often triangular-shaped) coaptation defect visible on 2D echocardiography. 3
Restricted leaflet motion: Found in 76% of patients with rheumatic aortic disease, corresponding to commissural fusion with or without associated thickening and calcification (fusion ranges from 11-73.8% in surgical series). 3
Prolapse or excessive leaflet motion: Aortic cusp tissue extending below the annular level occurs in 11% of acute rheumatic carditis cases, though this finding is not specific to rheumatic disease and requires clinical context for interpretation. 3
Tricuspid Valve Findings
Leaflet thickening: All patients with tricuspid valve involvement demonstrate thickened leaflets on echocardiography. 6
Doming, restricted motion, and calcification: These features occur in varying proportions when the tricuspid valve is organically involved, typically secondary to left-sided valve disease. 6
Tricuspid regurgitation and stenosis: Organic tricuspid involvement is not uncommon, though it receives less attention than left-sided disease. 6
Critical Diagnostic Considerations
The World Heart Federation criteria emphasize that these morphological features must be interpreted in clinical context, as they are not entirely unique to rheumatic disease. 3
Essential Exclusions
Congenital anomalies: Must rule out cleft mitral valve, double-orifice valve, or parachute variants before confirming rheumatic etiology. 1
Other etiologies: Degenerative disease, endocarditis, myxomatous degeneration, and functional regurgitation must be excluded through comprehensive echocardiographic and clinical assessment. 3
Common Pitfalls
Age-related variations: Commissural fusion and leaflet thickening are less frequent in children compared to adults, so absence of these features does not exclude acute rheumatic carditis in younger patients. 3
Acute versus chronic disease: In acute rheumatic carditis without prior valve disease, ventricular dilatation may be the primary mechanism of regurgitation rather than structural leaflet abnormalities, and valvular nodules may be transient. 5
Functional assessment: The majority of patients with rheumatic carditis have normal left ventricular systolic function; congestive heart failure occurs only when hemodynamically significant valve lesions are present. 5