Contrast echocardiography in the diagnosis of intrapulmonary vascular dilations in candidates for liver transplantation.

Abstract

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. 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 harmonic imaging. Thirty-two of them underwent consecutive transesophageal 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. The prevalence of intrapulmonary vascular dilations was 53.9% (41/76 patients). The sensitivity, specificity, positive and negative predictive values, and accuracy of transthoracic echocardiography as compared with those of transesophageal echocardiography 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 echocardiographic study. Arterial hypoxemia (PaO2 < 70 mm Hg) was observed in 9 (15.9%) of the 76 patients. The echocardiographic study was positive in 37 (55.2%) of the 67 nonhypoxemic patients and in 4 (44.4%) of the 9 hypoxemic ones. 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 intrapulmonary vascular dilations, the transesophageal study being reserved for inconclusive cases with clinical suspicion.