[Pulmonary hypertension – a common condition in left heart disease]

Pulmonary hypertension (PH) is a serious complication to left heart disease (LHD), affecting a majority of the patients during the course of the disease. Initially, PH-LHD is caused by passive congestion of the pulmonary vessels due to increased left atrial pressures, a condition that is currently denoted as isolated post-capillary PH (Icp-PH). In the majority of patients the increased atrial pressure is a result of elevated left ventricular filling pressures. Furthermore, chronically elevated filling pressures may yield endothelial damage, resulting in structural and functional alterations in the pre-capillary bed with further elevation in pulmonary pressures as well as elevated vascular resistance, defined as combined precapillary and postcapillary PH (Cpc-PH). With previous definitions of PH-LHD it has been difficult to differentiate between the subgroups, so a new classification was presented in the 2015 PH guidelines. Despite PH-LHD being common and serious, specific therapies are lacking for the pulmonary component. Instead, treatments focus on optimizing the underlying cause of PH-LHD and involve medical as well as surgical therapies. In the present review we presents, based on the new guidelines, current knowledge on pathophysiological and pathobiological mechanisms, epidemiology, investigation and treatment of PH-LHD.