POSTCAPILLARY PULMONARY HYPERTENSION



This results from the passive effects of an ele­vated left atrial pressure due to mitral valve dis­ease or prolonged left ventricular failure. If it per­sists, pulmonary artery pressure gradually increases above that explained by passive trans­mission of the elevated outflow pressure. Initially this increase is due to reflex vasoconstriction, but eventually vascular remodeling occurs. This addi­tional contribution to pulmonary hypertension can be quantified by the increasing gradient be­tween the pulmonary diastolic pressure and the left atrial pressure.