20.1 : 肺高血圧症：分類と病因

Pulmonary hypertension, or PH, denotes the resting mean pulmonary arterial pressure of 25 mm Hg or higher.

Pulmonary hypertension can be classified into PH due to left heart disease, lung diseases or hypoxia, chronic thromboembolic PH, PH with unclear multifactorial mechanisms, and pulmonary arterial hypertension or PAH.

PAH is a rare, fatal condition characterized by vascular changes in small arteries and arterioles, leading to elevated pulmonary arterial pressure and vascular resistance.

The key mechanisms in PAH include pulmonary vascular remodeling, sustained pulmonary vasoconstriction, in situ thrombosis, and stiffening of the pulmonary vascular wall.

Decreased vasoactive mediators like prostacyclin and increased vasoconstrictors like ET-1 contribute to vasoconstriction.

Symptoms of PH encompass dyspnea, fatigue, chest pain, and syncope.

Potential therapeutic options for PH include cGMP signaling stimulators, nitric oxide therapies, membrane receptor antagonists and agonists, and ion channel blockers.