Streptococcal Tonsillitis and Acute Streptococcal Myocarditis: An Unusual Combination Assessed by Cardiac Magnetic Resonance Imaging and Endomyocardial Biopsy

Objectives: Acute streptococcal tonsillitis is occasionally combined with myocarditis. Our aim was to examine patients with tonsillitis in whom myocarditis was suspected by using cardiac magnetic resonance imaging (MRI) and endomyocardial biopsy. Methods: After prospective evaluation of 200 patients with tonsillitis, 17 men (median age, 23 years; age range, 18 to 29 years) were recruited for cardiac MRI because of a suspicion of myocarditis. Chest pain 3 to 5 days after tonsillitis was the main complaint in 15 patients, and atypical chest discomfort in 2 patients. We performed cardiac MRI including short TI inversion recovery T2-weighted scanning and T1-weighted scanning with early gadolinium enhancement (EGE) and late gadolinium enhancement (LGE). The left ventricular ejection fraction and the presence of myocarditis were evaluated by the standard protocol. A T2 ratio of greater than 2 and an EGE value of greater than 4 were considered abnormal. Heart biopsy was suggested for patients with a reduced left ventricular ejection fraction. Results: Cardiac enzyme levels were increased in 8 of the 17 patients. Increased T2 ratio values (median, 2.8; range, 2.5 to 4.0) were documented in 16 patients. The EGE values were increased (median, 12; range, 8 to 19) in 16 patients. Positive LGE was identified in 13 patients. Endomyocardial biopsy in 4 patients revealed acute myocarditis, and polymerase chain reaction analysis identified streptococcal genomes. Re-evaluation by cardiac MRI 3 months later showed normal results in 14 patients. Conclusions: Acute streptococcal tonsillitis can be occasionally complicated by myocarditis with either a typical or an atypical presentation. Cardiac MRI can facilitate the diagnosis in both forms and allow a noninvasive follow-up.