Salmonella Perimyocarditis Without Bacteremia

Description of Clinical Presentation: Salmonella Myo-pericarditis is rare and carries significant mortality (14.8% in a recent review) ¹.
While typically resulting from transient bacteremia secondary to gastrointestinal infection,
peri-myocardial involvement without bloodstream infection is very unusual.

Diagnostic Techniques and Their Most Important Findings:

Methods:
A 23-year-old male with recent stool PCR–confirmed Salmonella gastroenteritis
presented with acute substernal chest pain radiating to the jaw and right shoulder.
Troponin levels were elevated (peaking at 954 ng/L). Initial ECG demonstrated diffuse
ST elevation consistent with pericarditis. Physical exam and baseline vitals were
unremarkable. Laboratory workup showed CRP 0.6 mg/dL and ESR 36 mm/hr; blood
cultures remained negative. Transthoracic echocardiogram revealed preserved
biventricular function without pericardial effusion. Due to persistent chest pain despite
aspirin, cardiac MRI was performed for further characterization.

Results:
Cardiac MRI (1.5 T GE) demonstrated preserved LVEDV 125 mL (LVEDVi 63.6 mL/m²),
LVEF 52%, RVEDV 119 mL (RVEDVi 60.5 mL/m²), RVEF 54%, and no regional wall
motion abnormalities. Native T1 mapping was elevated with diffuse myocardial signal
abnormality. Late gadolinium enhancement revealed subepicardial/pericardial LGE
involving the LV apex and RV free wall (extent 54.6% LV mass), consistent with active
inflammatory change. No significant pericardial effusion was noted. The patient was
treated conservatively with colchicine 0.5 mg twice daily for 3 months, low-dose aspirin,
and beta-blockade. Symptoms improved without evidence of recurrence on follow-up,
and cultures remained negative throughout hospitalization.

Learning Points from this Case: This case emphasizes the role of cardiac MRI in diagnosing Salmonella-associated
perimyocarditis in the absence of bacteremia. Given prior reports of high mortality¹ and primary
spread via transient gastrointestinal bacteremia², prompt imaging and anti-inflammatory therapy
may be lifesaving. Clinicians should consider MRI early in young patients with recent enteric
infection, chest pain, and biomarker elevation even when blood cultures are negative.

Late gadolinium enhancement (LGE) cardiac MRI in a vertical long-axis view demonstrates patchy subepicardial enhancement in the lateral wall (arrows), a non-ischemic distribution consistent with acute myopericarditis.
The short Axis LGE demonstrates patchy subepicardial enhancements in the lateral wall of the left ventricle (yellow arrow), consistent with non-ischemic pattern typical of myopericarditis.