Does rheumatic myocarditis really exists? Systematic study with echocardiography and cardiac troponin I blood levels

Revised guidelines for diagnosis of rheumatic fever indicate that rheumatic myocarditis may 'contribute' to the genesis of congestive heart failure. Our objective was to assess non-invasively the presence of non-clinical markers of myocardial involvement in acute rheumatic fever.

Echocardiography and assessment of cardiac troponin I (cTnI) blood levels were systematically performed in 95 consecutive patients with acute rheumatic fever, who were divided into three groups. Group 1: patients without carditis (n=22); group 2: patients with carditis and without congestive heart failure (n=59); group 3: patients with carditis and congestive heart failure (n=14).

Left ventricular ejection fraction was normal in all patients and did not differ between groups (group 1: 0.72+/-0.08, group 2: 0.69+/-0.06, and group 3: 0.66+/-0.07, p=0.09). Left ventricular diameters tend to be larger in group 3, but all patients had severe mitral and/or aortic regurgitation. Mean cTnI was 0.077+/-0.017 ng/ml (normal <0.1 ng/ml), did not differ between groups (p=0.45), and only 13 patients (seven with pericardial effusion) had detectable levels (0.2-0.4 ng/ml).

Our study neither detected cTnI elevations nor echocardiographic abnormalities suggesting significant myocardial involvement during rheumatic fever. Congestive heart failure was always associated to severe valve regurgitation.