Echocardiographic Assessment of Left Ventricular Diastolic Dysfunction: Differentiating a Pulmonary Vascular From a Pulmonary Venous Origin of Pulmonary Hypertension

Abstract

Pulmonary hypertension (PH) is a heterogeneous condition that may be due to a primary pulmonary arteriolar vasculopathy (pulmonary arterial hypertension or PAH: Group I), or secondary to left heart disease and pulmonary venous hypertension (PVH: Group II), chronic respiratory conditions (Group III), chronic thromboembolic disease (CTEPH: Group IV) or miscellaneous/multifactorial causes (Group V).12 The clinical diagnoses themselves are as diverse as the varied hemodynamic compositions of PH. Pulmonary hypertension ultimately results from varying interactions between pulmonary blood flow, pulmonary vascular resistance (PVR), conduit vessel compliance, and downstream left atrial (LA) pressure. Therefore, PH may also result from abnormalities in one or more of these factors. Patients with PAH, CTEPH, and most Group III patients have a “precapillary” hemodynamic profile with a normal LA pressure and an increased PVR as the primary mechanism of their PH. In contrast, patients with PVH (“postcapillary”) have increased LA pressure, most often with a normal or only mildly elevated PVR.