Typical Echocardiographic Appearance of Rheumatic Mitral Valve Disease
The correct answer is C: Leaflet thickening with restriction of the anterior mitral valve, commonly described as "hockey-stick" deformity. This represents the classic chronic echocardiographic finding in rheumatic heart disease (RHD) affecting the mitral valve.
Characteristic Morphological Features
The World Heart Federation guidelines explicitly describe the combination of morphological changes in RHD, with colloquial descriptions including "dog-leg," "elbow," or "hockey stick" deformities that portray leaflet thickening combined with restricted motion of the anterior mitral valve leaflet 1. This finding represents chronic mitral valve changes that are pathognomonic for established RHD 1.
Chronic Mitral Valve Changes in RHD
The American Heart Association identifies the following chronic morphological features on echocardiography 1:
- Leaflet thickening - the hallmark finding
- Chordal thickening and fusion - distinguishes rheumatic from other etiologies
- Restricted leaflet motion - creates the characteristic "hockey stick" appearance
- Calcification - seen in advanced disease
These chronic changes are specifically noted as "not seen in acute carditis" but rather represent established RHD 1.
Why Other Options Are Incorrect
Option A (Late posterior displacement with thickening and redundancy): This describes myxomatous degeneration or Barlow syndrome, not RHD 1. The American Heart Association specifically distinguishes rheumatic mitral valve prolapse from the redundant, myxomatous valve seen in Barlow syndrome - in ARF, only the coapting portion of the anterior leaflet tip prolapses without billowing of the medial portion or body 1.
Option B (Echogenic masses on valve or endocardium): This describes vegetations seen in infective endocarditis, which can be mistaken for rheumatic carditis but represents a different pathology 1. While focal valvular nodules (rheumatic verrucae) can occasionally be seen in acute rheumatic carditis, they are transient and disappear on follow-up 2.
Option D (Systolic doming and "sail sign"): This description is anatomically inconsistent with mitral valve pathology. Doming occurs during diastole in mitral stenosis, not systole 3.
Clinical Context and Diagnostic Considerations
Mitral Valve Predominance
RHD almost universally affects the mitral valve, with 99.3% of echocardiographic cases and 100% of postmortem examinations showing mitral valve involvement 1. The mitral valve is the most commonly affected valve in RHD, with mitral regurgitation being the most frequent finding (87-94% of cases) 4, 2.
Progression from Acute to Chronic Disease
In acute rheumatic carditis, morphological changes may include 1:
- Annular dilation
- Chordal elongation
- Anterior leaflet tip prolapse
- Beading/nodularity of leaflet tips
However, the chronic changes of leaflet thickening, chordal fusion, and restricted motion develop over time and represent established RHD 1.
Practical Diagnostic Approach
When evaluating suspected RHD on transthoracic echocardiography 1:
- Assess mitral valve morphology first - look for the combination of leaflet thickening, restricted motion, and the "hockey stick" deformity
- Evaluate for commissural fusion - a key feature distinguishing rheumatic from other etiologies 5
- Document associated regurgitation or stenosis - mitral regurgitation (87.2%) and stenosis (85.1%) are most common 4
- Exclude congenital anomalies - cleft mitral valve, double-orifice valve, or parachute variants must be ruled out 1
Common Pitfall
Do not confuse the restricted "hockey stick" appearance of chronic RHD with the anterior leaflet tip prolapse seen in acute rheumatic carditis 1. The chronic restricted motion is fundamentally different from the prolapse pattern and represents fibrotic changes rather than acute inflammation 1.