We studied the relation between right ventricular (RV) hypokinesis on echocardiography and defects on the initial perfusion lung scan among 90 hemodynamically stable patients with pulmonary embolism (PE). Of the 90, 38 had qualitative evidence of RV hypokinesis, with a mean RV end-diastolic area significantly larger than those with normal RV wall motion (40.0 +/- 10.2 cm2 vs 20.1 +/- 6.4 cm2; p < 0.001). The degree of the perfusion defect was greater in those patients with baseline RV hypokinesis (54% +/- 16% of the lung nonperfused) than in those patients with normal RV wall motion at baseline (30% +/- 18% nonperfused lung; p < 0.001). Receiver operating characteristic curve analysis showed that a perfusion lung scan defect score of 0.3 (i.e., 30% of the lung nonperfused) had a 92% sensitivity for predicting RV hypokinesis and carried a relative risk for observing RV hypokinesis of 6.8 times greater than among those patients with a perfusion scan score of < 0.3. Considering that all patients with recurrent symptomatic PE were in the subgroup with RV hypokinesis (13% vs 0% for those with normal RV wall motion; p = 0.01), a strategy of performing echocardiography in those patients with a perfusion scan defect score of > or = 0.3 appears to identify patients at increased risk for recurrent PE.