Electrocardiographic and echocardiographic changes in perinatal asphyxia

Asphyxia, Therapeutic Hypothermia, and Pulmonary Hypertension

Neonates with a perinatal hypoxic insult and subsequent neonatal encephalopathy are at risk of acute pulmonary hypertension (aPH) in the transitional period. The phenotypic contributors to aPH following perinatal asphyxia include a combination of hypoxic vasoconstriction of the pulmonary vascular bed, right heart dysfunction, and left heart dysfunction. Therapeutic hypothermia is the standard of care for neonates with moderate-to-severe hypoxic ischemic encephalopathy. This review summarizes the underlying risk factors, causes of aPH in neonates with perinatal asphyxia, discusses the unique phenotypical contributors to disease, and explores the impact of the initial insult and subsequent therapeutic hypothermia on aPH.

Relationships between cardiovascular signs and neurological signs in asphyxiated neonates in Ilorin, North Central Nigeria

Background

Perinatal asphyxia is a condition associated with multiple organ dysfunctions inclusive of cardiovascular dysfunction. Neurologic predictors of survival have been studied, but little has been reported regarding cardiovascular signs and their role in determining outcome in asphyxia.

Objective

The study aimed to determine the relationship between cardiovascular signs and outcomes in asphyxiated newborns with hypoxic ischaemic encephalopathy.

Methods

This was a cross sectional study involving asphyxiated new-born babies recruited within the first 24 hours of life. Hypoxic ischaemic encephalopathy staging was done using Sarnat and Sarnat staging. All patients had a detailed cardiovascular examination on admission, after initial resuscitation (30 – 60 minutes) into admission, and were followed till final outcome: discharge or death.

Results

Eighty-five asphyxiated new-borns with HIE were studied over seven months. Abnormal cardiovascular-related signs identified in the patients included respiratory distress (64.7%), small volume pulse (57.6%), hypotension (52.9%), hypoxemia (48.2%) and shock (32.9%). Five babies died. None of the clinical signs had a significant relationship with mortality.

Conclusion

Abnormal cardiovascular signs increased with the progression of HIE staging but had no relationship with mortality.

Application of Neonatologist Performed Echocardiography in the Assessment and Management of Neonatal Heart Failure unrelated to Congenital Heart Disease

Neonatal heart failure (HF) is a progressive disease caused by cardiovascular and non-cardiovascular abnormalities. The most common cause of neonatal HF is structural congenital heart disease, while neonatal cardiomyopathy represents the most common cause of HF in infants with a structurally normal heart. Neonatal cardiomyopathy is a group of diseases manifesting with various morphological and functional phenotypes that affect the heart muscle and alter cardiac performance at, or soon after birth. The clinical presentation of neonates with cardiomyopathy is varied, as are the possible causes of the condition and the severity of disease presentation. Echocardiography is the selected method of choice for diagnostic evaluation, follow-up and analysis of treatment results for cardiomyopathies in neonates. Advances in neonatal echocardiography now permit a more comprehensive assessment of cardiac performance that could not be previously achieved with conventional imaging. In this review, we discuss the current and emerging echocardiographic techniques that aid in the correct diagnostic and pathophysiological assessment of some of the most common etiologies of HF that occur in neonates with a structurally normal heart and acquired cardiomyopathy and we provide recommendations for using these techniques to optimize the management of neonate with HF.

A Clinical Study of the N-Terminal pro-Brain Natriuretic Peptide in Myocardial Injury after Neonatal Asphyxia

BACKGROUND

We aimed to study the changes of serum N-terminal pro-brain natriuretic to peptide (NT-proBNP) levels after asphyxia-induced myocardial injury in children and explore the relationship between serum NT-proBNP levels and neonatal asphyxia.

METHODS

One hundred and six cases of neonatal asphyxia were randomly selected for the study, including 46 severe cases with myocardial injury and 60 mild cases with no cardiac injury. Sixty-three healthy newborns were selected as the control group. The serum NT-proBNP level was detected using electrochemiluminescence. Creatine kinase MB (CK-MB) and serum sodium and calcium were measured simultaneously.

RESULTS

The serum NT-proBNP level in the myocardial injury group was significantly higher than that of the noncardiac injury and control groups (p < 0.01). Asphyxia serum NT-proBNP and cardiac enzymes were significantly correlated. The median value of neonatal NT-proBNP was 1491 pg/mL at postnatal Day 3 (P3) and 1077 pg/mL at postnatal Day 14 (P14). The cutoff value for children with myocardial injury was 3612.5 pg/mL; the area under the receiver operating characteristic curve was 0.80 (p < 0.001), with a sensitivity of 83.3%, a specificity of 80.5%, a positive predictive value of 82.8%, and a negative predictive value of 79.4%. After treatment, the serum NT-proBNP level in children with myocardial damage showed a significant decrease.

CONCLUSION

The serum NT-proBNP level can reflect myocardial injury in neonates with asphyxia and can guide its diagnosis.

The Diagnostic Value of Troponin T Level in the Determination of Cardiac Damage in Perinatal Asphyxia Newborns

Perinatal asphyxia is a clinical condition which results from oxygen deprivation of the fetus or newborn and the breakdown of perfusion in various organs. The aim of this study was to evaluate and compare troponin T levels over time as a marker of cardiac injury in cases of perinatal asphyxia and healthy newborns. The study included a total of 30 newborns diagnosed with perinatal asphyxia with a gestational age of 32-41 weeks, based on the last menstruation date, and 30 healthy newborns with a gestational age of 34-40 weeks, as the control group. Levels of troponin T and creatinin kinase MB were recorded for all participants. No difference was determined between the groups in terms of gestational age, manner of birth, electrocardiographic findings, and PaO2 and PaCO2 values. The umbilical artery pH levels and bicarbonate levels in the study group were found to be statistically lower than those in the control group (p < 0.001). The troponin T and creatinin kinase MB levels in the patients in the study group were higher than those within the control group, at all times. The periods when specificity and sensitivity were highest together for troponin T were the 12th and 24th h. Specificity for troponin T reached the highest value at the 24th h and sensitivity reached the highest value in the cord blood. A positive correlation was found between the troponin T and creatinin kinase MB values at the 6th and 12th h. However, no correlation could be found in the blood between the serum troponin T and creatinin kinase MB levels at the 3rd and 24th h. The troponin T level is a useful test for showing cardiac damage in hypoxic patients in the neonatal period. The sensitivity and specificity of cardiac specific troponin T levels in detecting cardiac damage are much higher according to telecardiography and electrocardiography, while the implementation of the method is simple.

Ventricular tachycardia due to perinatal asphyxia

BACKGROUND

Perinatal asphyxia is known to precipitate myocardial dysfunction, rhythm abnormalities and congestive cardiac failure.

CASE CHARACTERISTICS

A 2-day old neonate with perinatal asphyxia.

OBSERVATION

He developed shock secondary to ventricular tachycardia, and required synchronized cardioversion for reversion of abnormal rhythm.

OUTCOME

Reversal of arrhythmia leading to recovery.

MESSAGE

Early identification and management of ventricular tachycardia in neonate with perinatal asphyxia can be life-saving.

Effect of birth asphyxia on p wave dispersion

OBJECTIVES

To evaluate the cardiac conduction system using P wave dispersion on electrocardiogram and its relationship with the short term mortality and development of arrhythmia in asphyxiated neonates.

METHODS

Thirty term babies with evidence of asphyxia and without any congenital abnormalities were consecutively evaluated as cases. They were compared with thirty healthy term babies without asphyxia. Twelve-lead surface electrocardiography was obtained from all the patients and the controls, and P wave dispersion was calculated according to its definition as the difference between P maximum duration and P minimum duration in 12-lead electrocardiogram.

RESULTS

A statically significant difference of P wave dispersion was observed between the patients and the control group (0.027 ± 0.011 mm/s and 0.016 ± 0.006 mm/s, respectively; P value = 0.0001). The P wave dispersion had a statistically significant correlation with the grade of asphyxia (P = 0.004, r = 0.62), the P wave dispersion had no statistically significant correlation with Apgar scores, short term arrhythmia, and troponin I level in asphyxiated neonates (P < 0.05).

CONCLUSIONS

The P wave dispersion increased in asphyxiated neonates and correlated with grade of asphyxia; however, the increased P wave dispersion was not correlated with the short term mortality, arrhythmia and troponin I level of the asphyxiated neonates.

The assessment of time-dependent myocardial changes in infants with perinatal hypoxia

OBJECTIVE

The aim of the study was to assess myocardial damage in infants due to perinatal hypoxia.

METHODS

The findings of 29 infants with perinatal hypoxia and 20 healthy infants were compared. Blood gas analysis, serum lactate, cardiac troponin I (cTnI), troponin T (cTnT), creatine kinase-MB (CK-MB) and B-type natriuretic peptide (BNP) were evaluated. Echocardiography together with tissue Doppler imaging was performed.

RESULTS

cTnT, CK-MB and BNP were higher in patients at the first day. There were positive correlations between the left ventricular (LV) myocardial performance index (MPI) and cTnT at first day and also at first month. LV ejection fraction and fractional shortening were lower at first day and at first month in patients. Myocardial systolic (Sm) and diastolic (Em and Am) velocities at all segments were lower at first day, and interventricular septum Sm, LV Sm, LV Em, right ventricular Em and LV Am were still lower at first month in patients. Isovolumic relaxation time at all segments together with LV MPI was higher at first day, ejection time values were lower and MPI values were higher at all segments at first month in patients.

CONCLUSIONS

These findings demonstrated that the signs of myocardial damage due to perinatal hypoxia still present at first month.

Myocardial performance assessment in neonates by one-segment strain and strain rate analysis by tissue Doppler - a quality improvement cohort study

OBJECTIVES

To investigate one-segment strain and strain rate indices as measures of myocardial performance in asphyxiated term neonates.

DESIGN

Quality improvement cohort study.

SETTING

Newborns admitted to a neonatal intensive care unit at a Norwegian University Hospital for perinatal asphyxia and non-asphyxiated newborn recruited from the maternity ward at the same hospital.

PARTICIPANTS

Twenty asphyxiated and 48 non-asphyxiated term neonates.

PRIMARY OUTCOME MEASURE

Strain and strain rate indices and repeatability measures. One-segment longitudinal strain and strain rate by tissue Doppler were assessed on days 1, 2 and 3 of life in nine heart walls. Repeatability was compared against measurements from two-segment analyses previously performed in the same images.

RESULTS

The 95% limits of agreement were significantly better for the one-segment than two-segment repeatability analyses, the inter-rater peak systolic strain (PSS) was (-3.1, 3.3) vs (-11.4, 18.3)%, the inter-rater peak systolic strain rate (PSSR) was (-0.38, 0.40) vs (-0.79, 1.15)/s, the intra-rater PSS was (-2.5, 2.6) vs (-8.0, 9.8)% and the intra-rater PSSR was (-0.23, 0.25) vs (-0.75, 0.80)/s (p<0.05). The myocardial performance was lower in the asphyxiated neonates (indices closer to zero) than in the non-asphyxiated neonates, PSS was -17.8 (0.6) (mean (SEM)) vs -21.2 (0.3)%, PSSR -1.43 (0.08) vs -1.61 (0.03)/s, early diastolic strain rate 1.72 (0.11) vs 2.00 (0.11)/s and strain rate during the atrial systole 1.92 (0.17) vs 2.27 (0.10)/s (p<0.05), despite no difference in fractional shortening (29.0 (0.5) vs 29.1 (1.0)%) (p>0.05).

CONCLUSIONS

One-segment strain and strain rate assessed the reduced myocardial performance in asphyxiated neonates with significantly improved reproducibility as compared with two-segment analysis and was therefore more feasible than two-segment analyses for assessment of myocardial performance after perinatal asphyxia.