Echocardiographic observation on pulmonary arterial diastolic pressure and resistance before and after oxygen inhalation in 30 newborns

Summary

Using the echocardiographic technique before and after oxygen inhalation, we observed pulmonary and aortic valves of 30 normal newborns within 24 hrs after birth. Right ventricular pre-ejection period/ right ventricular ejection time ratio (RVPEP/RVET) and left ventricular pre-ejection period/left ventricular ejection time ratio (LVPEP/LVET) were measured from the pulmonary and aortic valve echocardiograms respectively, and then the R/L, i.e. (RVPEP/RVET): (LVPEP/LVET) ratio, was also calculated. According to Riggs’ and Spooner’s equations^{[3, 4]} we calculated the pulmonary arterial diastolic pressure (PADP), the pulmonary arterial resistance (PAR) and pulmonary/systemic resistance ratio (PAR/RS). The findings obtained suggest that the echocardiographic observations on pulmonary and aortic valves, as a method for non-invasive determination of PADP, PAR and PAR/RS ratio, can be used to differentiate functional vasoconstrictive pulmonary hypertension from organic pulmonary hypertension, if the observation of RVPEP/RVET ratio is repeated after inhalation of high concentration of oxygen.