DIAGNOSTIC UTILITY OF CONTRAST ECHOCARDIOGRAPHY AND LUNG PERFUSION SCAN IN PATIENTS WITH HEPATOPULMONARY SYNDROME

Background & Aims: Two modalities, contrast echocardiography and lung perfusion scan, are used to identify intrapulmonary vascular dilatatio n and diagnose hepatopulmonary syndrome (HPS), but a comparison of the se two procedures has not been performed. The aim of this study was to compare the use of these diagnostic modalities in detecting intrapulm onary vascular dilatation and diagnosing HPS. Methods: Forty consecuti ve outpatients with biopsy-proven cirrhosis had contrast echocardiogra phy, a lung perfusion scan, and arterial blood gases analyzed. Results : Fifteen of 40 cirrhotics (38%) had positive contrast echocardiogram results. Seven patients with positive echocardiogram results had gas e xchange abnormalities and could be considered to have HPS (7 of 40 [17 .5%]). Three of these patients were hypoxemic and had no concurrent ca rdiopulmonary disease, and each had positive contrast echocardiogram a nd lung perfusion scan results and were readily diagnosed as having HP S. The other 4 patients (3 hypoxemic and 1 normoxemic with an elevated alveolar-arterial gradient) had coexisting intrinsic lung disease and /or chest radiograph abnormalities complicating the diagnosis of HPS, and each had positive echocardiogram and negative lung scan results. T he remaining 8 patients with positive echocardiogram results had norma l lung scan and normal gas exchange results. No patient had positive l ung scan and negative contrast echocardiogram results. Conclusions: Co ntrast echocardiography is the most useful screening test for intrapul monary vasodilatation and may be positive more frequently than lung pe rfusion scans in patients with HPS.