Incidence of abnormal RNA studies and dysrhythmias in patients with blunt chest trauma.

The incidence and significance of myocardial contusion and subsequent cardiac complications have recently been debated. A prospective study of patients with blunt chest trauma was undertaken at a Regional Trauma Unit between January 1, 1989 and March 31, 1990. One hundred ninety-one patients were entered into the study; 72-hour Holter monitoring was performed in 183 patients, and radionuclide angiography (RNA) was performed on 163 patients. All patients had CPK levels (with CPK-mb fractions) measured, and serial electrocardiographs. There were seven patients with abnormal RNA studies; five of the seven abnormal studies were attributable to previously undiagnosed coronary artery disease or myocardial infarction. Nine patients were diagnosed as having atrial fibrillation, seven of whom were in atrial fibrillation on admission. Ventricular dysrhythmias were classified by the number of premature ventricular contractions (PVCs) per hour or the presence of ventricular tachycardia. Twelve patients developed short runs of ventricular tachycardia, and clinically insignificant PVCs were common. Only one patient with ventricular dysrhythmias (frequent PVCs) was treated and there were no hemodynamically significant dysrhythmias. The incidence of clinically significant dysrhythmias or hemodynamically significant myocardial contusion appears to be low in this patient population. Aggressive investigation and monitoring solely for cardiac complications may not be indicated.