Myocardial ischaemia in neonates with perinatal asphyxia - Electrocardiographic, echocardiographic and enzymatic correlations

In asphyxiated neonates, hypoxia is often responsible for myocardial ischae mia. To evaluate cardiac involvement in neonates with respiratory distress, ECC and echocardiographic recordings were performed, and cardiac enzymes d etermined. These data were related to clinical presentation and patient out come. Three groups of neonates were studied: 22 healthy newborn infants (gr oup I) with 5 min Apgar scores >9 and pH >7.3; 15 neonates with moderate re spiratory distress (group II) which had Apgar scores ranging between 7 and 9, and pH between 7.2 and 7.3; and 13 neonates with severe asphyxia, Apgar scores <7, and pH <7.2 (group III). The ECGs were evaluated according to th e 4-grade classification proposed by Jedeikin et al. [8]. On the echocardio grams, fractional shortening and aortic flow curve parameters were taken in to account. Serum creatine kinase (CK), creatine kinase-MB isoenzyme (CK-MB ) and lactate dehydrogenase were determined. All of groups I and II survive d, but 5 out of 13 in group III died within the 1st week. Grade 3 or 4 ECG changes were observed only in group III patients, while all group II and 3 patients of group I showed grade 2 ECG changes. Fractional shortening, peak aortic velocity and mean acceleration were significantly reduced in group III, whereas the only abnormality found in group II was a reduced fractiona l shortening. CK, CK-MB, CK-MB/CK ratio and lactate dehydrogenase were all increased in group III, while in group II only CK-MB and the CK-MB/CK ratio were abnormal. Conclusion Severely asphyxiated newborn infants reflect relevant ischaemic electrocardiographic changes, depressed left ventricular function and marke d cardiac enzyme increase. These alterations are far less pronounced in neo nates with mild respiratory distress.