Case Of the Month 4 – Answer

This is a young man with almost no significant medical history presenting with symptoms that sound infectious: bloody diarrhea, cough, chest pain, and fever.  This tips us off that he might have some type of GI or pulmonary infection causing his symptoms.  But, his EKG is vastly concerning for a cardiac process with ST elevations in V1-V3 and depressions in II, aVF, and V5-V6, with a LBBB pattern.  His troponin is also mildly elevated with systolic dysfunction in this otherwise healthy gentleman.  This places diagnoses with cardiac myocyte damage such as MI, myocarditis, CHF, rheumatic fever, and coronary vasospasm on our radar.  His CXR is normal however he may still have an early pneumonia developing and if so, PNA + GI symptoms should trigger a brief thought process about legionella.  Also, he is on sertraline for depression and we should get a better history about any recent dosage changes.  Although serotonin syndrome does not typically occur from a single agent, perhaps there is some other hidden history about addition of new meds or overdose on his home med. Serotonin syndrome can present with diarrhea and fever although there is usually more neurologic findings (clonus, AMS, etc) and would be less likely in his case.  Finally, the fact that he has bloody diarrhea signifies either some type of inflammatory infection (Salmonella, Shigella, Campylobacter, etc.) or other inflammatory process (e.g. IBD) and perhaps can be linked to the signs of his cardiac damage.

The diagnosis that most easily explains all of his symptoms is myocarditis.  Myocarditis is inflammation of the cardiac tissue and can present subtly or fatally depending on how severe the cardiac damage is, how healthy the patient’s heart was before the process began, and how long it takes for the diagnosis to be made.  Patients will typically present with signs of heart failure and pulmonary congestion, however they can also present with mild pain and/or signs of pericarditis, or possibly ECG changes such as AV block and fatal arrhythmias.  Causes can be divided into infectious vs. non-infectious.  Infectious can be viral (most common), bacterial, or fungal.  Non-infectious etiologies include sarcoid, rheumatic fever, eosinophilic myocarditis, giant cell myocarditis, andperipartum myocarditis.

 

Given his recent onset of diarrhea and fevers, an infectious cause to explain his GI symptoms and the myocarditis is most likely.  Although viral is the most common infectious cause of myocarditis, viral enteritis rarely produces bloody inflammatory diarrhea.  Of the bacteria and pathogens that cause inflammatory diarrhea, Campylobacter jejuni and Salmonella strains have been associated with the development of myocarditis/pericarditis.  There are case reports of these pathogens as a cause of myocarditis largely in immunocompromised or pediatric individuals, however it can be seen in immunocompetent adults as well.  The mechanism is theorized, but unknown.  They are rare causes, and many texts and articles summarizing the bacterial causes of myocarditis rarely review these pathogens.  Your only clue is suspicion from the inflammatory diarrhea. Diagnosis revolves around isolating Campylobacter or Salmonella in stool cultures and then confirming myocarditis via cardiac imaging and/or biopsy. Campylobacter/Salmonella grown from the biopsy specimen is the gold standard of diagnosis but biopsy is rarely performed; patients are usually treated presumptively with clinical improvement used as a sign of the diagnosis.  HIV tests should be sent on any patient with suspected non-viral myocarditis as it is rarer to have this pathology with a normal immune system.

Campylobacter is managed typically with ciprofloxacin 500mg po BID or azithromycin, although a standard regimen for Campylobacter myocarditis has not been established from my poring over of case reports.  Some reports describe treatment for 5-7 days with good success.  It’s important to know that some strains of Campylobacter are showing resistance to floroquinolones and therefore antibiotic therapy should be guided by sensitivities obtained from stool culture.  Salmonella is usually managed symptomatically as symptoms typically resolve within 5 days, however antibiotics are recommended for “complicated infections”.  Assuming myocarditis is one of those complications, treatment is with floroquinolones or 3rd generation cephalosporins.  Again, I could find no standard treatment regimen for Salmonella myocarditis.  Treatment does not necessarily improve cardiac function back to baseline although when treated early, most young, previously healthy patients show no residual cardiac deficits.

All in all, this case should highlight the importance of keeping myocarditis in your mind when managing patients with chest pain, fever, and elevated cardiac enzymes.  If suspecting an infectious source viruses may be king, however using the symptoms available to us, we may be able to ascertain a different cause and start treatment early in the ED.