Detection of pulmonary emboli and associated right heart dysfunction by combining ventilation perfusion lung scanning and xenon ventriculography.

PURPOSE The authors sought to determine if the right ventricular ejection fraction (RVEF), as measured by xenon ventriculography, is depressed in patients with pulmonary emboli. The authors also sought to correlate any decrement in RVEF with the extent of lung perfusion defects. MATERIALS AND METHODS The authors identified all patients who had lung ventilation-perfusion (V/Q) scans between January 1994 and December 1996, that were interpreted as high probability for pulmonary embolism. From these patients, the authors selected those who had undergone concurrent xenon ventriculography (XV) (n = 23), and then reprocessed the initial ventriculography data for confirmation. The authors also reviewed original V/Q scans, chest radiographs, and clinical data. A control group was drawn from patients with normal V/Q scans who had undergone XV. RESULTS Fifteen patients (65%) with high probability V/Q scans had an abnormally low RVEF (< .32). Patients with high probability V/Q scans also had a significantly lower mean RVEF (0.28 +/- .08) than patients with normal V/Q scans (.39 +/- .08 SD). The degree of RVEF decline correlated poorly with the number of segmental perfusion defects (r = -.39). CONCLUSIONS RVEF is often depressed in patients with high probability V/Q scans. XV can identify these patients, while routine lung V/Q scans cannot.