Acute nonrheumatic streptococcal myocarditis: STEMI mimic in young adults

Am J Med. 2012 Dec;125(12):1230-3. doi: 10.1016/j.amjmed.2012.06.016. Epub 2012 Oct 9.


Background: Mimicking ST-segment elevation myocardial infarction upon presentation, acute nonrheumatic streptococcal myocarditis is a treatable etiology of myocarditis which has only been infrequently reported.

Methods: Patients were identified through a retrospective query of electronic medical records over a 17-year period (January 1994 to December 2010). We describe a case series of acute nonrheumatic streptococcal myocarditis complicating pharyngitis in young adults.

Results: Nine patients were identified; 89% were male, patients had an average age of 28.6 years, and 56% and 22% had confirmed group A and group G streptococcus, respectively. Latency from pharyngitis to chest pain averaged 3.1±1.1 days. No patients met the revised Jones criteria for acute rheumatic fever. All 9 patients (100%) presented with ST-segment elevations on electrocardiography and elevated cardiac biomarkers. Average peak creatine kinase was 934 U/L (normal<400 U/L), creatine kinase-MB was 82 ng/mL (normal<6.9 ng/mL), and troponin T was 2.30 ng/mL (normal<0.03 ng/mL). Six patients underwent coronary angiography, which revealed no obstructive culprit lesions. Cardiac magnetic resonance imaging confirmed myocarditis in 3 patients and was used to document resolution in follow-up for 2 patients. All patients had a complete clinical recovery.

Conclusions: Acute nonrheumatic streptococcal myocarditis is an under-recognized and treatable cause of ST-segment elevation and chest pain in young adults with a history of recent pharyngitis. Etiopathology extends beyond Lancefield group A streptococcus and includes group G streptococcal infection. Cardiac magnetic resonance may be useful in confirming the diagnosis and documenting the resolution.

MeSH terms

  • Adult
  • Biomarkers / blood
  • Chest Pain / etiology
  • Coronary Angiography
  • Creatine Kinase / blood
  • Diagnosis, Differential
  • Echocardiography
  • Electrocardiography*
  • Female
  • Humans
  • Magnetic Resonance Imaging, Cine
  • Male
  • Myocardial Infarction / diagnosis
  • Myocarditis / diagnosis*
  • Myocarditis / microbiology*
  • Pharyngitis / etiology
  • Retrospective Studies
  • Streptococcal Infections / diagnosis*
  • Streptococcus pyogenes
  • Troponin T / blood
  • Young Adult


  • Biomarkers
  • Troponin T
  • Creatine Kinase