Dyspnoea is the most common symptom of pulmonary arterial hypertension (PAH ). Up to 75 % of patients with PAH are diagnosed in advanced stages of the disease. Patients with PAH associated with systemic connective tissue (CTD) have a poor prognosis, especially patients with systemic sclerosis. Despite modern therapy is a maximum 3 -year survival less favorable than in other forms of PAH 51 % vs 87%. Early stages of PAH are characterized by abnormal hypertensive response of pulmonary circulation to exercise. The aim of our study was to examine exercise-induced changes in invasive pulmonary hemodynamics in patients with CTD and compare them to other patients with dyspnoea of unknown etiology. Patients and methods The study included 77 patient with dyspnoea of unknown etiology (age 54.7±13.4 years, 80% females) and 12 CTD patients (age 58.9±11.4 years, 50 % females). All patients underwent a detailed non-invasive testing including echocardiography, pulmonary function tests, V/P scintigraphy or CT angiography to exclude left heart disease, pulmonary disease and chronic thromboembolic disease. Subsequently, a pulmonary artery catheterization was performed via the right internal jugular vein using a Swan-Ganz catheter. Cardiac output was measured by thermodilution method. After obtaining resting hemodynamic parameters, patients underwent symptom-limited stepwise exercise protocol on a recumbent bike (20W start load plus 10W increments in 3 min steps) with continuous hemodynamic monitoring.
Hemodynamics at rest and at peak exercise is presented in table 1.
Precapillary pulmonary hypertension is frequent in patients with CTD and is characterized by pronounced hypertensive response during exercise. Excessive hypertensive response in pulmonary circulation can be responsible for higher prevalence of RV dysfunction and worse prognosis of CTD patients.