Exercise intolerance in pulmonary arterial hypertension is driven by complex pathophysiological mechanisms, predominantly ventriculoarterial uncoupling, RV maladaptation, and peripheral muscle dysfunction.
This review highlights the complex pathophysiological mechanisms, including ventriculoarterial uncoupling, right ventricular maladaptation, and peripheral factors, that contribute to exercise intolerance in pulmonary arterial hypertension.
Pulmonary arterial hypertension (PAH) is a chronic disease with poor prognosis and important exercise limitation despite the proliferation of treatment options in the last decade. Chronically increased right ventricular (RV) afterload results in right heart failure and without treatment, rapid clinical deterioration is common. Exercise intolerance is the cardinal feature of the disease impacting upon quality of life and clinical outcome. The pathophysiological mechanisms that lead to reduced exercise capacity in this population are complex with ventriculoarterial uncoupling likely to be the predominant feature. The relative contributions of additional factors that contribute to exercise limitation beyond ventriculoarterial uncoupling have not been characterized. This review addresses these factors with a focus on recent developments and uncertainties. RV maladaptation and the intricate interplay between the heart, abnormal pulmonary vascular bed and peripheral factors such as dysfunction of the respiratory and peripheral muscles are discussed in detail.
Tran et al. (Sun,) conducted a review in Pulmonary arterial hypertension. Exercise intolerance in pulmonary arterial hypertension is driven by complex pathophysiological mechanisms, predominantly ventriculoarterial uncoupling, RV maladaptation, and peripheral muscle dysfunction.