Mitral Regurgitation is the Cardiac Complication Most Closely Associated with Rheumatic Fever
The answer is A. Mitral regurgitation is the hallmark cardiac manifestation of rheumatic fever, occurring in the vast majority of patients with rheumatic carditis.
Primary Valvular Involvement in Rheumatic Fever
Mitral regurgitation is the most consistent and common cardiac finding in acute rheumatic fever, present in 84-94% of patients with rheumatic carditis 1, 2.
The mitral valve is primarily affected in rheumatic carditis, with valvulitis being the most consistent feature of the disease 1, 3.
Aortic valve involvement occurs less commonly and rarely occurs in isolation without concurrent mitral valve disease 1, 4, 5.
Mechanism of Mitral Regurgitation in Rheumatic Fever
The pathophysiology differs from other causes of mitral regurgitation:
Ventricular dilatation (54-74% of cases) and restriction of leaflet mobility (37% of cases) are the primary mechanisms causing mitral regurgitation in rheumatic carditis 2.
Only the coapting portion of the anterior mitral valve leaflet tip prolapses, without billowing of the medial portion or body of the leaflet, creating abnormal leaflet coaptation with posterolaterally directed regurgitation 1, 5.
Valve prolapse (9-16%) and annular dilatation (12-21%) are infrequent mechanisms in rheumatic carditis 2.
Why the Other Options Are Incorrect
Aortic valve stenosis (Option C): While rheumatic fever can eventually lead to aortic stenosis in chronic rheumatic heart disease, this develops years after the acute episode and is invariably accompanied by mitral valve disease 5. It is not a primary acute complication.
Aortic aneurysm (Option B): This is not associated with rheumatic fever. Aortic aneurysms result from conditions like Marfan syndrome, bicuspid aortic valve, atherosclerosis, or vasculitis—not from rheumatic pathology.
Pulmonary hypertension (Option D): While pulmonary hypertension can develop as a secondary consequence of severe mitral valve disease in chronic rheumatic heart disease 1, 6, it is not a primary cardiac complication of acute rheumatic fever itself.
Clinical Implications
Approximately 30-65% of patients with acute rheumatic fever develop valvular heart disease 5, 7.
Carditis occurs in 50-87% of patients during their first episode of acute rheumatic fever 3, 6.
The American Heart Association guidelines recognize both clinical and subclinical (echocardiographic) carditis as major criteria in the revised Jones criteria 1.
Echocardiography with Doppler should be performed in all cases of confirmed or suspected acute rheumatic fever to detect mitral regurgitation, even when clinical auscultatory findings are absent 1, 3.