Systemic abnormalities in liver disease

Table 1 Difference between HPS and PPHTN modified from Rodríguez-Roisin et al[4]

	HPS	PPHTN
Prevalence	11%-32% of patients with liver cirrhosis	2% of patients with portal hypertension
Pathogenesis	Increased intrapulmonary shunting	Unknown
Intrapulmonary vascular dilatations	(+)	(-)
Pulmonary arterial hypertension	(-)	(+)
Symptom	Dyspnea, platypnea	Dyspnea on exertion, syncope, chest pain
Clinical manifestations	Cyanosis	No cyanosis
	Orthodeoxia	Accentuated pulmonary component of IIs
	Spider nevi	Systolic murmur, edema
ECG findings	None	RVH, RBBB, right axis deviation
Arterial blood gas levels	Moderate-to-severe hypoxemia (< 60-80 mmHg)	No/mild hypoxemia
Chest radiography	Normal	Cardiomegaly, hilar enlargement
CEE	Positive finding; left atrial opacification for > 3-6 heart beats after right atrial opacification	Usually negative finding
99mTcMAA shunting index	≥ 6%	< 6%
Pulmonary hemodynamics	Normal/low PVR	Elevated PVR mPAP > 25 mmHg at rest or > 30 mmHg with exercise
OLT	Indicated in severe stages	Only indicated in mild-to-moderate stages

HPS: Hepatopulmonary syndrome; PPHTN: Portopulmonary hypertension; RVH: Right ventricle hypertrophy; IIs: Second heart sound; ECG: Electrocardiography; RBBB: Right bundle-branch block; AaPO₂: Alveolar arterial oxygen gradient; CEE: Contrast-enhanced echocardiography;

^99mTcMAA: Technetium-99m-labelled macroaggregated albumin; PVR: Pulmonary vascular resistance; mPAP: Mean pulmonary artery pressure; OLT: Orthotopic liver transplantation.