Pulmonary Artery Pressure in Young Healthy Subjects

Abstract

Pulmonary artery systolic pressure (PASP) is frequently measured noninvasively using transthoracic echocardiography. Normal values of PASP are based on studies performed in heterogeneous populations. The normal values of PASP in young healthy subjects are poorly defined. The aim of this study was to describe the distribution and clinical and morphologic correlates of PASP values in young healthy subjects. Echocardiography is routinely performed for aircrew candidates for the Israeli Air Force. All echocardiographic examinations performed between 1994 and 2010 in which tricuspid regurgitation was present, a prerequisite for echocardiographic PASP measurement, were collected. Subjects with morphologic abnormalities were excluded. PASP was calculated using the simplified Bernoulli equation, with right atrial pressure assumed to be 5 mm Hg. The associations between PASP and clinical and echocardiographic characteristics were studied. Subjects were healthy young adults aged 17 to 29 years. Evidence of tricuspid regurgitation was found in 1,900 of 6,598 subjects. The estimated mean PASP value was 31.2 ± 4.5 mm Hg, and the upper 95th percentile was 34 mm Hg. In univariate analysis, PASP was correlated with left ventricular end-diastolic and end-systolic diameters. A multivariate linear regression model including age; diastolic blood pressure; echocardiographic measurements of aortic root, left atrial, and left ventricular end-diastolic diameters; and left ventricular mass explained only 7% of the variability in PASP. PASP in young, physically fit subjects may be higher than previously reported in the general population and is poorly explained by age, blood pressure, and other echocardiographic parameters.