M-mode subxiphoid echocardiography in assessing pulmonary hypertension. Its usefulness in chronic obstructive...

12 patients (9 males, 3 females; aged 35-63 years, mean 55) with chronic obstructive pulmonary disease (COPD) were studied in order to determine the correlation between the values of pulmonary arterial pressure and the M-mode echographic size of the right pulmonary artery (RPA) from the subxiphoid approach. Both the largest (systolic) and smallest (diastolic) size of the vessel were considered, and both were corrected for body surface area ('index size' - PA/BSA). The reliability of this echographic size is supported by the evidence that the tract of the pulmonary artery considered in this study is perpendicular to the ultrasonic beam. Both the systolic and diastolic size of RPA correlated with the systolic, diastolic, and mean pulmonary arterial pressure, detected by catheterization. Measurements of RPA size were made from the suprasternal approach in 8 patients out of 12. The size of RPA from the subxiphoid approach was also estimated in 21 normal subjects, serving as controls. Measurements of RPA size from the suprasternal approach were made in 12 of these subjects. Both the systolic and diastolic size of RPA from the subxiphoid approach correlated with the systolic and diastolic size of the suprasternal view in patients and in normal subjects. Subxiphoid M-mode echocardiography seems to be a valuable noninvasive technique in assessment of pulmonary hypertension, particularly in patients affected by COPD.