18 - Current treatment of pulmonary vascular diseases

Summary

Introduction

The normal pulmonary circulation is an adaptable compliant system, allowing for large variations in blood flow with relatively small changes in resistance and pulmonary artery pressure. This flexibility is gradually lost in the face of progressive vascular damage due to an intrinsic disease process or a recurrent acute insult, and results in pulmonary hypertension.

The pathological changes were first described by Romberg in 1891 in a patient with unexplained pulmonary arteriosclerosis. In 1951, Dresdale et al. coined the term primary pulmonary hypertension and widespread awareness of the disease came with the epidemic of pulmonary hypertension, blamed on the use of the appetite suppressant aminorex fumarate, that swept Europe in 1967. It took almost 90 years for the first effective medical and surgical treatment to become available, but in the past 10 years there have been dramatic improvements in both quality of life and survival with the use of calcium channel blockers and prostacyclin. This has led to increasing recognition of the important role that pulmonary vascular disease plays in many disease processes, and renewed interest in early diagnosis and intervention.

Definition and classification

Pulmonary hypertension is defined as a mean pulmonary artery pressure of over 25 mmHg at rest or 30 mmHg during exercise.