CASE REPORT

A 55 year old man was admitted to our hospital with de novo diabetes mellitus, dehydration, and high fever. Blood cultures demonstrated Escherichia coli (identified using the VITEK® identification system (bioMérieux Inc, Hazelwood Missouri, USA)) bacteraemia, for which antibiotic treatment with ceftriaxone (2 g/day intravenously) was initiated. Abdominal computed tomographic (CT) scanning revealed multiple splenic abscesses, and E coli was cultured from the aspirates of these abscesses. During rehydration, the patient developed signs of left sided heart failure. A cardiac ultrasound demonstrated left ventricular inferoposterolateral wall motion abnormalities, indicating a recent myocardial infarction. A thoracic CT scan surprisingly revealed intramyocardial gas collections in the left ventricle (fig 1A, B). We hypothesised that these might result from a localised myocardial infection with gas producing E coli, and indeed the E coli that was cultured from the blood was found to be gas forming (fig 1C). Intramyocardial gas gangrene is a rare finding, which has previously been reported in association with infections with gas forming clostridium.^{1, 2} However, certain strains of E coli are able to produce large amounts of nitrogen, carbon dioxide, and hydrogen in vitro,^{3, 4} and have been shown to cause gas accumulation in vivo—for example, in emphysematous pyelonephritis.⁵ Serial thoracic CT scans showed that the intramyocardial air collections decreased in size during antibiotic treatment. Unfortunately, the patient died during an episode of ventricular fibrillation. Postmortem analysis confirmed the inferoposterolateral intramyocardial abscess, which was culture positive for E coli, in a recently infarcted area (fig 1D).

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Figure 1

(A). Computed tomography (CT) scan (three dimensional reconstruction) showing intramyocardial air collections (arrow). (B) CT scan (transverse) showing intramyocardial air collections (arrow). (C) Agar tubes demonstrating gas production by cultured Escherichia coli (lower tube with agar before addition of cultured E coli; upper tube after overnight incubation with E coli showing accumulation of gas within the agar). (D) Macroscopic picture of intramyocardial abscess (arrows).