"From right to left": The role of right heart catheterization in the diagnosis and management of left heart diseases.

Pulmonary hypertension (PH), second only to left heart diseases (LHD), is a frequent problem in clinical practice. At the same time, left heart diseases represent the most common cause of pulmonary hypertension, and the occurrence of PH in patients with chronic heart failure is usually associated with worse functional class, and prognosis. Right heart catheterization (RHC) is the "gold standard" in the diagnosis and differentiation of PH. It is also essential in the process of qualifying for a heart transplantation. Therefore, right heart catheterization should be performed in expert centers by experienced operators and according to a strict protocol to ensure the reliability and reproducibility of results. Recommendations for pulmonary hypertension due to left heart disease are based on the European Society of Cardiology (ESC) guidelines designed in cooperation with the European Respiratory Society (ERS) and the International Society for Heart and Lung Transplantation (ISHL). The new ESC guidelines for pulmonary hypertension published in 2015 have improved the diagnostic and therapeutic process in patients with left heart diseases.