Cerebral blood flow velocity wave form as an indicator of neonatal left ventricular heart function.

OBJECTIVE: To investigate the relationship between cerebral blood flow velocity wave form (CBFV-WF) parameters and myocardial contractility indices in healthy and sick preterm and term newborns.

METHODS: Total group of 82 babies was divided into four subgroups: prematures with gestational age <34 weeks with (n=20) and without (n=14) respiratory distress syndrome (RDS) and infants with gestational age of >33 weeks with (n=18) and without (n=30) asphyxia. On day 1, 2, 3, 6 and 14, the acceleration time, Q(ECG)-peak(flow) time and preejection period of CBFV-WF (internal carotid artery) were measured through the anterior fontanel by Doppler ultrasonography. Simultaneously cardiac output, fractional shortening, systolic time intervals and their ratio were determined echocardiographically.

RESULTS: RDS-babies had higher cardiac output and better myocardial performance then non-RDS-babies. Asphyxiated babies had lower cardiac output as compared to healthy babies, improving over time. Correlations were found between CBFV-WF parameters and several myocardial function indicators, but preejection period of cerebral blood flow velocity correlated closest with the same period measured echocardiographically (r=0.67, P<0.0001). Multiple linear regression revealed no influence of gestational age or clinical condition on this relationship. Assessment of agreement indicated that only substantial changes in myocardial performance could be monitored using preejection period of CBFV.

CONCLUSION: Although a relationship was detected between the preejection period of CBFV and left ventricular systolic time interval (used as indicator of changes in left ventricular function), only rather large changes in left ventricular performance can be reliably detected using the preejection period of CBFV.