Assessment of Left Atrial Ejection Force in Mildly Asphyxiated Newborns

Objective: Asphyxia-induced cardiac insult is one of the major causes of mortality and morbidity in the course of perinatal asphyxia. Nowadays, a remarkable trend of interest is sensed introducing a plausible modality for early detection of cardiac insults at the beginning stages of asphyxia. In this study we aimed to evaluate diagnostic utility of transmitral Doppler–derived parameters as well as left atrial ejection force index as a marker of left atrial contractile function in these patients.
Methods: In a prospective study selected cases of 26 asphyxiated newborns with preserved systolic function underwent conventional transmitral Doppler flow echocardiographic assessment. Left atrial ejection force index was further calculated for all patients. Data was compared with normal ranges of healthy newborns in order to clarify the diagnostic utility of these parameters for determining minor cardiac insults in this age group.
Findings: We found that mildly asphyxiated newborns showed an increase in the values of left atrial ejection force index (5.44±2.12 kilodyne vs. 6.66±2.17 kilodyne, P= 0.02) and left atrial filling fraction (39%±10% vs. 45%±8%, P= 0.01). Furthermore, the acceleration and deceleration rate of early filling flow peak velocity were decreased in this group of asphyxiated newborns.
Conclusion: Assessment of left atrial ejection force in mildly asphyxiated newborns reveals that newborns with even mild asphyxia, although could not be categorized in conventional grading system, suffer to some extent from a ventricular filling abnormality. This type of latent ventricular filling abnormality could simply be unmasked by calculation of atrial ejection force index.