Myocardial infarction after dog bite.

To the Editor: We do not agree with the diagnosis of myocardial infarction in the case of a 36-year-old man 2 days after a dog bite1. For several reasons, we believe that the patient had myopericarditis rather than myocardial infarction. First, the patient had symptoms, signs, and laboratory findings consistent with sepsis, and blood cultures yielded Capnocytophaga canimorsus. Myocardial infarction occurs occasionally in patients with bacteremia, and it usually results from sepsisassociated hypotension or from endocarditis with septic embolism to the coronary arteries. However, viral and bacterial infections are more commonly the cause of pericarditis and myocarditis.2,3 ECG patterns of acute myopericarditis are known to resemble those seen with acute myocardial infarction.4 The presented ECG demonstrated ST elevations in both anterior and inferior leads in a manner consistent with the pattern found in acute myopericarditis.4,5 Second, the absence of regional wall motion abnormalities and the documentation of diffuse hypokinesia with left ventricular systolic dysfunction are typically seen in myopericarditis. Abnormal regional wall motion is nearly universally present in acute myocardial infarction. Presentation with chest discomfort and laboratory examinations with elevated levels of creatine kinase and raised troponin-I concentrations are consistent with myopericarditis as well as with myocardial infarction. Third, coronary angiography demonstrating normal vessels without signs of atherosclerosis is also consistent with the diagnosis of myopericarditis. This finding makes acute myocardial infarction less likely but does not definitely rule out previous coronary artery occlusion. In summary, we think that the diagnosis of acute myopericarditis is more likely than acute myocardial infarction in the reported case.1