Recent clinical and laboratory findings indicate comparable pathophysiological mechanisms in pulmonary hypertension secondary to left ventricular dysfunction and pulmonary arterial hypertension. Yet, despite an expanding application in pulmonary artery hypertension, according to current opinion, the oral dual endothelin (ETA/ETB) antagonist bosentan is not indicated for PVH caused by left ventricle / left atrial pressure overload and preserved systolic function. However, there are several studies which show some effects of pulmonary vessel dilating drugs in PAH and left ventricle dysfunction.