MYOCARDIAL ISCHEMIA IN NEONATE WITH PERINATAL ASPHYXIA: ELECTROCARDIOGRAPHIC, ECHOCARDIOGRAPHIC AND ENZYMATIC CORRELATION

Tissue Doppler imaging versus conventional echocardiography in assessment of cardiac diastolic function in full term neonates with perinatal asphyxia

Background and objective: Limited number of studies evaluated cardiac diastolic function in neonates with perinatal asphyxia using tissue Doppler imaging. The aim of this study was to evaluate the echocardiographic parameters in full-term neonates with perinatal asphyxia compared to healthy full-term neonates. Diagnostic value of echocardiographic parameters of diastolic dysfunction in predicting mortality in asphyxiated neonates was assessed.Setting: Neonatal intensive care unit at the Obstetric and Gynecology Hospital, Cairo University, Egypt (a tertiary care center).Patients and methods: This study included 20 neonates with perinatal asphyxia (cases) and 20 healthy full-term nonasphyxiated neonates (as controls). The studied groups were assessed by conventional pulsed wave Doppler and tissue Doppler imaging.Results: Among pulsed wave Doppler parameters, cases had statistically significant lower values (denoting more diastolic dysfunction) than controls as regards mitral E velocity (p = .04) and mitral E/A ratio (p = .04). Similarly, among tissue Doppler parameters, cases had statistically significant lower values (denoting more diastolic dysfunction) than controls as regards septal E'/A' ratio (p = .019), left ventricular E' velocity (p = .001), and E'/A' ratio (p < .001). Septal E'/A' ratio and right ventricular E'/A' ratio were significantly lower (p = .012 and p = .025, respectively) among nonsurvivors (denoting more diastolic dysfunction) compared to survivors. Moreover, cases had statistically significant higher values (denoting more diastolic dysfunction) than controls as regards septal (p < .001), left ventricular (p < .001), and right ventricular (p < .001) tissue Doppler-based myocardial performance indices. Asphyxiated neonates showed statistically significant higher evidence of left ventricular diastolic dysfunction than controls in both pulsed wave Doppler and tissue Doppler with p < .001 and p = .001, respectively; while there was no difference as regards right ventricular diastolic dysfunction. Tissue Doppler was able to detect higher number of neonates with left ventricular diastolic dysfunction than conventional pulsed wave Doppler.Conclusions: Tissue Doppler imaging was found to be able to detect diastolic dysfunction early in neonates with perinatal asphyxia specifically as regards the left ventricle. Assessment of myocardial function is important in asphyxiated neonates. Tissue Doppler imaging should be considered an integral part of assessment of cardiac function in asphyxiated neonates.

Myocardial dysfunction as a predictor of the severity and mortality of hypoxic ischaemic encephalopathy in severe perinatal asphyxia: a case-control study

Background: In perinatal asphyxia, hypoxia often leads to myocardial ischaemia. Few studies have assessed the degree of myocardial dysfunction in severely asphyxiated term neonates. Aim: To assess the extent of myocardial damage in newborns with severe perinatal asphyxia. Methods: A case-control study was conducted in asphyxiated newborns with hypoxic ischaemic encephalopathy (HIE) and in controls who were term non-asphyxiated newborns. Total (T) creatinine kinase (CK), CK-MB, troponin-T and 12-lead electrocardiography (ECG) and echocardiography were performed in both groups within 24-48 h after birth. The proportions of asphyxiated neonates with myocardial dysfunction and its relationship between severity of HIE and immediate outcome was compared. Results: Five of 23 asphyxiated neonates developed stage I, 10 stage II and eight stage III HIE. Serum levels of CK-T and CK-MB were raised in all 23 cases and troponin-T was raised in 13 (56.5%) HIE cases. ECG was abnormal in all cases and echocardiography in three (13%). Left ventricular ejection fraction (LVEF) and right ventricular ejection fraction (RVEF) were significantly decreased in all asphyxiated neonates. Eight (35%) patients died. Enzyme levels were higher and ECG and echocardiography abnormalities were common in infants with more severe HIE (p <0.05). Mean serum levels of CK-T and MB (p <0.001) and troponin-T (p =0.002) were higher in non-survivors. Mean LVEF and RVEF values were higher in survivors (p <0.001). All the controls had normal enzyme levels and echocardiography. ECG was abnormal in one control. Conclusion: Cardiac enzymes, ECG and echocardiography changes were associated with increasing severity of HIE and mortality.