Pulmonary hypertension—hemodynamic assessment and response to vasodilators

INTRODUCTION The first observation of patients with pulmonary hypertension was described by a German physician Dr. Ernst von Romberg as “sclerosis of the pulmonary arteries” from autopsy findings (1). The term primary pulmonary hypertension (PPH) was used by Dresdale and colleagues in 1951, describing a hypertensive vasculopathy of pulmonary vessels of unknown cause (2). Paul Wood contributed to understanding of possible etiology of this disease by observing that a reduction in pulmonary artery pressure was seen in response to intravenous (IV) administration of acetylcholine in patients with pulmonary hypertension secondary to mitral stenosis, eliciting a proposal that a “vasoconstrictive factor” may be a cause (3).