Ejection characteristics in primary pulmonary hypertension

Abstract

Primary pulmonary hypertension (PPH) is a progressive vasculopathy of the pulmonary circulation which results in marked elevations of pulmonary artery (PA) pressure and pulmonary vascular resistance. 1–3 Cardiac output, initially preserved at rest, does not increase appropriately with exercise. 2,4,5 This combination of features explains the clinical symptoms of fatigue and dyspnea frequently present in these patients. Although considerable data exist characterizing central hemodynamics in patients with PPH, most of these studies have focused on nonpulsatile measures. Characterization of the phasic, or dynamic, nature of ejection not only provides detailed measures of instantaneous ejection performance but also can provide important insight into pathogenetic mechanisms. 6 Alterations in external vascular load will predictably affect ventricular ejection performance. The present study compares and contrasts right-sided dynamic ejection behavior at rest and during exercise in patients with PPH with an age-matched control population. Our intent was to demonstrate that phasic hemodynamics in the pulmonary circulation reflect the magnitude and nature of the PA vascular hydraulic load.