Non-Invasive Screening for Pulmonary Hypertension Using Ventilatory Gas Analysis

Chronic thromboembolic PH (CTEPH) and pulmonary arterial hypertension (PAH) are two subtypes of PH. CTEPH is characterized by organic thrombotic obstructions of pulmonary arteries, which reduce pulmonary vascular reserve. As new therapies are developed for CTEPH and PAH, prompt screening for the presence of PH, diagnosis and distinction between CTEPH and PAH have become increasingly important. Although their pathophysiology differs, the clinical presentation at rest is highly similar between CTEPH and PAH, as both disorders have only non-specific symptoms. Therefore, differentiating between CTEPH and PAH using non-invasive techniques remains challenging. This mini-review focuses on the role of ventilatory gas analysis in the management of PH patients, presents recent studies dealing with ventilatory gas analysis, and discusses the latest use of ventilatory gas analysis for diagnosing, assessing (in terms of severity), and distinguishing between CTEPH and PAH.