Amaç: Fetal yaşamdan postnatal yaşama geçiş döneminde, infantın kardiyovasküler sisteminde önemli değişiklikler meydana gelir. Bu çalışmada sağlıklı yenidoğanın kalp fonksiyonlarında meydana gelen değişiklikleri doğumdan hemen sonra Doppler ekokardiyografi ile saptamayı amaçladık. Gereç ve Yöntem: Çalışmaya vajinal yolla doğan 22 sağlıklı infant alındı. Çalışmaya alınan olguların doğum sonrası 1., 24. ve 72. saaderde kardiyak output (CO), stroke volüm (SV), kalp hızı (HR), ortalama kan basıncı (MBP), total periferik resistansı (TPR), ejeksiyon fraksiyonu (EF), sol ventrikül end-diyastolik volümü (LVEDV), sol ventrikül end-sistolik volümü (LVESV) ve ductus arteriosus (DA) çapı değerlendirildi. Bulgular: MBP'da 1. 24. ve 72. saatte (50 ±4 mmHg, 58 ±7 mmHg, 66 ±9 mmHg sırasıyla) anlamlı artış saptandı (p

Objective: Dramatic changes occur in the circulation of the newborn during the transition from fetal to neonatal life. Evaluation of the early changes in cardiac functions of healthy newborns non-invasively by using Doppler echocardiography was aimed. Methods: Cardiac functions of 22 healthy newborns, born vaginally, were evalu-ated. Cardiac output (CO), stroke volume (SV), heart rate (HR), mean blood pres-sure (MBP), total peripheral vascular resistance (TPR), ejection fraction (EF), ductus arteriosus (DA), left ventricle end diastolic volume (LVEDV) and left ventricle end systolic volume (LVESV) of the cases were examined by Doppler echocardiography, at 1st, 24th, and 72nd hours after birth. Results: The MBP values at 1st, 24th, and 72nd hours were 50 ±4, 58 ±7, and 66 ±9 mmHg, respectively; the differences between 1st hour and 24th and 72nd hours were found to be significant (p<0.05). The TPR values at 1st, 24th, and 72nd hours were 0.006 ±0.01, 0.073 ±0.021, and 0.08 ±0.022 mmHg x min/ml respectively. Similar to MBP, differences in TPR between 1st hour and 24th and 72nd hours were found to be significant. Diameter of the DA decreased significantly from 3,2±0.3 mm in the 1st hour to 0.21±0.11mm in the 24th hour, while no aperture was detected in the 72nd hour. Significant decreased (p<0.05) were noted between 1st and 24th hour values of CO, SV and LVEDV, but no signifcant difference was detected between the 24th and 72nd hour values of these parameters. (p>0.05 No significant difference was detected in LVESV and EF values during the 72 hours period (p>0.05). Conclusions: The factors effecting the normal changes in the cardiovascular system may be useful understanding the pathologic conditions after birth such as congenital heart diseases and hypoxia. These results suggest that closure of the DA (aperture?) and the increase in TPR are the most important factors affecting the basic changes in the cardiovascular system early in the neonatal period.