A comparison of echocardiography and pulmonary artery catheterization for evaluation of pulmonary artery pressures in pregnant patients with suspected pulmonary hypertension

OBJECTIVE: This study was undertaken to compare the accuracy of echocardiography versus pulmonary artery catheterization to estimate pulmonary artery pressures in pregnant women with suspected pulmonary hypertension. STUDY DESIGN: A retrospective chart review was performed between January 1990 and February 2000 for all pregnant patients with cardiac disease. Patients with pulmonary artery pressure values estimated by cardiac catheterization and echocardiography during pregnancy were included. Pulmonary hypertension is defined as pulmonary artery systolic pressure > 30 mm Hg. RESULTS: Twenty-seven patients were included in the study. There was a significant overestimation of the mean pulmonary artery pressure with echocardiography compared with catheterization (55.4 vs 51.1 mm Hg; P < .005). Of the 20 patients, pulmonary artery pressure was significantly greater when estimated by echocardiography than when measured by catheterization (59.6 vs 54.8 mm Hg; P < .004). Thirty-two percent (8/25) of the patients had pulmonary hypertension when estimated by echocardiography but had normal pulmonary artery pressures on subsequent catheterization. CONCLUSION: Echocardiography significantly overestimated pulmonary artery pressures compared with catheterization in pregnant patients with suspected pulmonary hypertension. Patients with structural cardiac defects appear to have a significantly greater difference in pulmonary artery pressures. Thirty-two percent of pregnant patients with normal pulmonary artery pressures may be misclassified as having pulmonary artery hypertension when measured by echocardiography alone.