The asymptomatic patient with suspected myocardial contusion.
 Diagnostic criteria and guidelines for hospital admission for suspected myocardial contusion (MCC) remain unclear.
 This study defines and examines the clinical sequelae of patients admitted with a suspicion of MCC.
 Criteria for observation following isolated, minor blunt chest trauma are suggested.
 Hospital and trauma registry records of patients admitted over a 33-month period with suspected MCC were reviewed.
 Conventional evaluation criteria, cardiac-related complications, and associated injuries were analyzed for 524 patients.
 Twenty-eight cardiac-related complications occurred in 27 of 524 patients (5%).
 These complications included 23 dysrhythmias, 3 infarctions, and 2 pericardial effusions.
 There were 23 patients with abnormal admission electrocardiograms and 4 with normal ones.
 Of the latter, one patient developed dysrhythmia 4 hours after admission, and three had other major multi-system injuries requiring admission to the intensive care unit.
 The overall incidence of cardiac-related complications in minimally injured patients was 0.1%.
 There were no complications in patients with isolated chest wall contusions, a normal admission electrocardiogram, and a normal rhythm at 4 hours.
 There was no significant association between creatine phosphokinase isoenzymes or echocardiogram and cardiac-related complications.
 The complete absence of significant cardiac sequelae in patients with isolated chest wall contusion, normal admission and 4-hour electrocardiograms, and no other associated major injuries suggests that these patients need not be admitted.
