Right ventricular tardokinesis in cardiac contusion: a new observation on phase images

The usefulness of gated blood pool (GBP) scintigraphy in evaluating cardiac contusion among trauma patients was examined. In ten of 62 patients who sustained blunt chest trauma, phase images of GBP studies demonstrated delayed onset of right ventricular (RV) contractions (RV tardokinesis). Clinical charts of these ten patients were reviewed to determine the significance of this finding. Only one had no supportive evidence of cardiac injury. Four patients were determined to have clinically significant cardiac contusion on the basis of the occurrence of arrhythmias of cardiac failure during their hospital course. These patients had ventricular histogram widths greater than 30 degrees of the entire cardiac cycle at half maximum height and had a bifid peak in their ventricular contraction histograms. Of the 52 patients who did not have RV tardokinesis, only one had a clinically significant cardiac contusion, resulting in a false-negative rate of 2% for the test. This new observation of RV tardokinesis may be clinically useful in establishing the difficult diagnosis of cardiac contusion.