Ga. Abrams et al., DIAGNOSTIC UTILITY OF CONTRAST ECHOCARDIOGRAPHY AND LUNG PERFUSION SCAN IN PATIENTS WITH HEPATOPULMONARY SYNDROME, Gastroenterology, 109(4), 1995, pp. 1283-1288
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.