Severe abdominal pain, often accompanied by gastrointestinal symptoms and fever, may be the first and most prominent symptom of myocardial or pericardial disease. This has been well recognized in adults, and examples of myocardial infarction masking as acute cholecystitis or perforated peptic ulcer have been frequently recorded. Acute pericarditis has similarly been confused with a number of acute surgical diseases. With the exception of abdominal pain as a frequent manifestation of acute rheumatic fever, the counterpart of these experiences in childhood has not been emphasized.
The cases selected for this study fit largely into the categories of acute interstitial myocarditis or acute idiopathic pericarditis. In addition 2 cases of acute bacterial pericarditis were included. Cases with involvement of the myocardium or pericardium as a part of a widespread septic disease were omitted. Cases of rheumatic heart disease, diphtheritic myocarditis, endocardial fibroelastosis, congenital heart disease, and idiopathic myocardial hypertrophy were excluded.