CASE PRESENTATION: A 66-year-old woman with history of liver cirrhosis underwent a duct-to-duct biliary anastomosis OLT. Pre-operative autoimmune serology showed an elevated C4 complement of 4.9mg/dL, quantitative C-reactive protein of 46.8mg/dL, and rheumatoid factor of 55IU/mL. An echocardiogram showed an ejection fraction of 72%, normal left and right ventricular (RV) size and wall motion, right atrial pressure (RAP) 5mmHg, right ventricular systolic pressure (RVSP) 23mmHg, and mean pulmonary artery pressure (MPAP) 14mmHg. Saline contrast revealed delayed right-to-left shunt suggestive of intrapulmonary source. Arterial blood gas shunt study revealed calculated shunt fraction of 5%; therefore, mild hepatopulmonary syndrome (HPS) was diagnosed. Pulmonary function testing showed normal spirometry with diffusion capacity of 41% predicted. CT did not show fibrosis, discrete arteriovenous malformations, or chronic thromboembolic disease. She had an uncomplicated OLT, but two months after later she developed severe dyspnea and syncopal episodes. Liver function tests were normal and an echocardiogram revealed severe RV enlargement and hypokinesis. A right heart catherization showed a RAP 3mmHg, MPAP 35mmHg, wedge 4mmHg, transpulmonary gradient 31mmHg, cardiac output 3.1L/min, and a calculated pulmonary vascular resistance (PVR) of 827 dyne*sec cm-5. She declined prostanoid therapy; therefore, she was initiated on sildenafil, ambrisentan, and inhaled treprostinil. The patient’s symptoms dramatically improved and her most recent echocardiogram showed normal RV size and function, RAP 5mmHg, RVSP 18mmHg, and MPAP 15mmHg.