D'Alto Michele, Vergara Andrea, Orlando Antonio, Naeije Robert
Adult Congenital Heart Disease Unit, Department of Cardiology, Monaldi Hospital, Naples, Italy.
Free University of Brussels, Brussels, Belgium.
Curr Opin Pulm Med. 2025 Sep 1;31(5):464-469. doi: 10.1097/MCP.0000000000001189. Epub 2025 Jul 4.
Left heart disease (LHD) is the commonest cause of pulmonary hypertension (PH). The differential diagnosis between PH associated with LHD (PH-LHD) and pulmonary arterial hypertension (PAH) may be difficult. PH associated with LHD is causally related to chronically increased pulmonary artery wedge pressure (PAWP). However, PAWP may be "falsely" normal or high-normal at the time of diagnostic right heart catheterization.
Updated guidelines for step-by-step diagnosis of PAH and LHD leave nevertheless a proportion of patients with PH and diagnostic uncertainty. In these patients, several studies have shown that a PAWP >18 mmHg after a rapid infusion of 500 ml saline is associated with a high likelihood of LHD. Evidence has been accumulated that patients with PH, cardiovascular risk factors and a high-normal PAWP should have LHD excluded by a fluid challenge. Preliminary studies suggest that the test may be performed noninvasively by combining Doppler echocardiography and lung ultrasound showing respectively a ratio of trans-mitral flow E wave to mitral annulus tissue velocity e' (E/e') ≥12 and ≥5 B-lines.
A fluid challenge has a place in the step-by-step diagnostic work-up of patients referred for PH for the differential diagnosis between PH-LHD and PAH.
左心疾病（LHD）是肺动脉高压（PH）最常见的病因。与左心疾病相关的肺动脉高压（PH-LHD）和肺动脉高压（PAH）之间的鉴别诊断可能存在困难。与左心疾病相关的肺动脉高压与肺动脉楔压（PAWP）长期升高存在因果关系。然而，在诊断性右心导管检查时，PAWP可能“假性”正常或高正常。
尽管PAH和LHD的逐步诊断更新指南仍使一部分PH患者存在诊断不确定性。在这些患者中，多项研究表明，快速输注500ml生理盐水后PAWP>18mmHg与LHD的高可能性相关。已有证据表明，患有PH、心血管危险因素且PAWP高正常的患者应通过液体负荷试验排除LHD。初步研究表明，可通过分别结合显示二尖瓣血流E波与二尖瓣环组织速度e'（E/e'）之比≥12和≥5条B线的多普勒超声心动图和肺部超声进行无创性检查。
在因PH就诊患者的逐步诊断检查中，液体负荷试验在PH-LHD和PAH的鉴别诊断中具有一席之地。
