Title : Hypoxemia beyond the heart: A case of hepatopulmonary syndrome masquerading as cardiac dyspnea
Abstract:
Hepatopulmonary syndrome (HPS) is a serious pulmonary vascular complication associated with chronic liver disease, portal hypertension, or congenital portosystemic shunts. It is characterized by a triad of liver disease, intrapulmonary vascular dilatation, and arterial hypoxemia. HPS affects approximately 4-47% of patients with cirrhosis and significantly increases mortality, doubling the risk of death and reducing median survival. Currently, liver transplantation remains the only definitive treatment. It often presents non-specific symptoms leading to delays in diagnosis and treatment.
We present a 55-year-old Peruvian female patient with cirrhosis from metabolic dysfunction-associated steatotic liver disease, type 2 diabetes mellitus, hypertension, and hyperlipidemia. She presented with progressively worsening shortness of breath over three days and increased oxygen requirements from her baseline (3 L/min of oxygen via nasal cannula). She was found to be febrile, hypotensive and hypoxic requiring oxygen via high-flow nasal cannula. Laboratory findings were notable for normocytic anemia, mild thrombocytopenia, elevated transaminases, procalcitonin and lactate. Arterial blood gas showed elevated alveolar-arterial gradient. Blood and urine cultures were positive for Staphylococcus aureus. The patient was treated for septic shock. Chest imaging showed pulmonary edema. Oxygenation did not improve with diuresis and antibiotics. Transthoracic echocardiogram (TTE) with bubble study showed normal left ventricular ejecting fraction of 60-65%, and passage of bubbles into the left heart after four cardiac cycles. Right heart catheterization confirmed Qp/Qs (pulmonary/systemic flow) of 0.6 and identified bubbles crossing from the pulmonary artery into the left atrium, consistent with a significant intrapulmonary shunt. CT angiography of chest did not reveal arterio-venous malformations. Given increased alveolar-arterial gradient, portal hypertension secondary to hepatic cirrhosis, the diagnosis of hepatopulmonary syndrome was made.
This case emphasizes the critical role of advanced cardiac imaging and hemodynamic studies in identifying non-cardiac causes of hypoxia. HPS, often underrecognized in cardiology and pulmonary settings, may be misdiagnosed due to nonspecific symptoms like exertional dyspnea and limitations in imaging caused by comorbidities such as esophageal varices. Despite not being a primary cardiac etiology, comprehensive cardiac assessment was instrumental in diagnosing HPS. This patient remained on home oxygen for a year of unknown etiology before the diagnosis was made, highlighting the risk of delayed recognition. Given the poor prognosis of untreated HPS median survival of 10.6 months timely diagnosis is essential to initiate appropriate treatment and consider liver transplantation.
