Abstract
Chronic lung diseases are one of the most frequent causes of pulmonary hypertension (PH). The diagnostic challenge is to differentiate PH due to chronic lung disease from pulmonary arterial hypertension (PAH) with coexisting chronic lung disease. Moreover, the dominating cause of PH may change over time, requiring the implementation of new diagnostic procedures and new treatment modalities. We present a 68-year-old female, initially diagnosed with PH in the course of interstitial lung disease, with restrictive impairment of lung function. Therapy with immunosuppressive drugs resulted in significant clinical, radiological and functional improvement. However, five years later, arthritis symptoms developed, with PH worsening, despite stable lung disease. The patient was diagnosed with PAH in the course of rheumatoid arthritis. The introduction of sildenafil resulted in marked clinical and hemodynamic responses. Long-term survival (eleven years from PH onset and five years from PAH confirmation) has been achieved, and the patient remains in good functional condition. As the differential diagnosis of PH in patients with lung diseases is complex, the cooperation of pulmonologists and cardiologists is mandatory to obtain therapeutic success.