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Objective of the study: to study the role of nitric oxide (NO) in adaptive reactions of the circulatory system in premature infants with transient myocardial ischemia (TMI). Materials and methods of research: a clinical, prospective, comparative study was carried out from 2016 to 2018. 82 infants with gestational age of 31–36 weeks who have had respiratory failure were included. Newborns were divided into groups: 1st – 14 newborns with TMI ECG criteria and troponin I (TrI) >0.139 ng/ml, 2nd – 39 newborns with TMI ECG criteria and TrI<0.139 ng/ml, 3rd – 29 children with normal ECG and TrI<0.139 ng/ml. In the early neonatal period, the clinical status, blood gas analysis, ECG, echocardiography and determination of TrI and NO were carried out. Quantitative data are presented as median, 25th and 75th percentiles; qualitative – in absolute values and %. The statistical significance was assessed by the Mann–Whitney test, the analysis of the relationship was assessed by the Spearman's rank correlation coefficient. Results: the level of NO by the 7th day of life in premature newborns of the 1st group increased 3.8 times, in the 2nd and 3rd groups – 1.7 and 2.5 times. A correlation relationship was revealed between TrI and NO on the 7th day of life (r=0.793, p=0.006), between NO and pH (r=–0.738, p=0.036), NO and pCO2 (r=0.857, p=0.006) on the 1st day. Also, on the 1st day there was a statistically significant increase in the end diastolic (EDS) and end systolic sizes (EDS) of the left ventricle (LV), the relationship of LV EDS with NO (r=0.722, p=0.042) and TrI (r=0.666, p=0.049), as well as NO with the LA size (r=0.731, p=0.038) in the 1st group. Conclusions: in premature infants with TMI and destructive changes in the myocardium, an increase in NO is probably necessary to optimize LV contractility and compensate for damage to cardiomyocytes. In children with TMI in the absence of myocardial injury, a compensatory increase in NO contributes to limiting the effects of hypoxia by functional disorders of LV, which persist by the end of the early neonatal period.

Purpose. To assess frequency and severity of myocardial damage in premature infants with transient myocardial ischemia in the early neonatal period.Materials and methods. The study includes 73 newborns of a gestational age of 31–36 weeks with respiratory failure and oxygen dependence in the first 2 hours of life. Newborns are divided into groups: Group 1: classic electrocardiographic criteria of transient myocardial ischemia and an increase in the level of troponin I in the blood; Group 2: electrocardiographic criteria for transient myocardial ischemia and a normal level of troponin I; Group 3: no ECG changes and normal troponin I level. We assessed blood gases, conducted electrocardiography, determined troponin I in the blood on the 1st and 7th day of life, assesses duration of oxygen therapy in all the children.Results. Group I: troponin I concentration on the 7th day of life – 0.415 [0.222; 0.639] ng/ml, Group II – 0.073 [0.051; 0.104] ng/ml and Group III – 0.017 [0.006; 0.051] ng/ml. Transient myocardial ischemia was detected in 41% of examined patients, and destructive myocardial changes – in 21.9%. An analysis of the gas composition of blood in the first 2 hours demonstrated that there was a significant predominance of the level of bases in the children of Group I. The duration of artificial ventilation in children of Group I was 56 [3; 96] hours, exceeding the indicators of children of Group II (9 [8; 11]) by 5 times, and Group III (20.5 [13; 72]) – by 2.5 times. Also newborns in Group I experienced a maximum need for oxygen therapy through a mask.Conclusion. 21.9% of premature infants experience destructive myocardial changes against the background of transient myocardial ischemia; newborns with transient myocardial ischemia and destructive changes have a significantly more pronounced metabolic acidosis in the first hours of life and a longer need for oxygen therapy.

Красноярский государственный медицинский университет им. проф. В.Ф. Войно-Ясенецкого» Минздрава России, Красноярск 660022, Российская Федерация 2 Красноярский краевой клинический центр охраны материнства и детства, Красноярск 660074, Российская Федерация Резюме. В статье представлена история пациентки с транзиторной ишемией миокарда в периоде новорожденности на фоне перенесенной перинатальной гипоксии, у которой вторичная кардиомиопатия развилась за пределами раннего неонатального периода и в возрасте 2-х месяцев произошло наслоение приобретенного инфекционного заболевания сердца. Диагноз «Транзиторная ишемия миокарда» в практике неонатологов устанавливается не часто из-за отсутствия унифицированных критериев диагностики, однако данное состояние может маскироваться и отягощать течение респираторной патологии, что требует проведения дифференциальной диагностики и является важным для выбора правильной тактики ведения пациентов. Ключевые слова: новорожденный, транзиторная ишемия миокарда, инфекционный миокардит, цитомегаловирусная инфекция, неонатальный период, катамнез. Конфликт интересов. Авторы декларируют отсутствие явных и потенциальных конфликтов интересов, связанных с публикацией настоящей статьи.