Contrast Echocardiography in the Diagnosis of Intrapulmonary Vascular Dilations in Candidates for Liver Transplantation

Objective To determine the importance of contrast echocardiography in the diagnosis of intrapulmonary vascular dilations in patients with severe liver disease, who are candidates for liver transplantation. Methods The study comprised 76 patients with chronic liver disease and no evidence of intrinsic pulmonary disease, heart failure, or congenital heart disease with intracardiac communications, who underwent transthoracic echocardiography with second har- monic imaging. Thirty-two of them underwent consecutive tran- sesophageal study. The result of contrast echocardiography was considered positive when the presence of contrast was detected in the left cardiac chambers with a delay of 4 to 6 cardiac cycles after initial opacification of the right cardiac chambers. Results The prevalence of intrapulmonary vascular dilations was 53.9% (41/76 patients). The sensitivity, specificity, positive and negative predictive values, and accuracy of transthoracic echo- cardiography as compared with those of transesophageal echo- cardiography for confirming pulmonary vascular abnormalities in patients with liver disease were, respectively, 75%, 100%, 100%, 80%, and 87.5%. The degree of arterial oxygenation showed no correlation with the occurrence of a positive echo- cardiographic study. Arterial hypoxemia (PaO 2 < 70 mm Hg) was observed in 9 (15.9%) of the 76 patients. The echocardio- graphic study was positive in 37 (55.2%) of the 67 nonhypoxemic patients and in 4 (44.4%) of the 9 hypoxemic ones. Conclusion Contrast echocardiography proved to be effective, easy, and safe to use in candidates for liver transplantation. Transthoracic echocardiography may be used in the diagnostic routine of in- trapulmonary vascular dilations, the transesophageal study being reserved for inconclusive cases with clinical suspicion.