PLANIMETRIC ECG INDICATORS IN CHILDREN WITH PREMATURE VENTRICULAR EXCITATION BY THE TYPE OF CLC SYNDROME, CLC PHENOMENON AND MAHAIM

Аннотация

In thesyndrome ofpremature ventricular excitation (PVE)of theheart, part of the ventricular myocardium or the entire myocardium is activated by impulses conducted through accessory pathways (AP), and patients sooner or later develop tachyarrhythmic attacks, which under certain conditions are transformed into atrial and ventricular fibrillation, posinga threat to thepatient's life. Manifestations of PVE are rare - from 0.15 to 3.1% of the general population, including 9% of the total number of children with cardiac arrhythmias. This disease manifests itself in different forms - from constant clinical and electrophysiological manifestations in the manifest form to theabsence ofany subjective and objectivesymptoms in thelatent form. Key words: arrhythmia, accessory pathways, pre-excitation of the ventricles of the heart, planimetry, children. Introduction. The problem of cardiac arrhythmias and complications associated with them has become especially relevant in pediatrics in recent years [3, 5, 9, 10]. There are a number of heart diseases, such as premature ventricular excitation syndrome (PVS), these cardiac arrhythmias are based on re-entry mechanisms caused by the presence of the AP impulse, theECGexpression ofwhich are varieties of PVS(syndromes and phenomena: WPW,CLC, Mahaima-Levi). There is no reliable data in the literature on the prevalence of arrhythmias caused by AP in children [5, 6,7]. Unlike adults, in children, rhythm disturbances associated with AP are often asymptomatic and, in 40.0 - 60.0%, are an accidental finding. Active detection and examination of children with arrhythmias due to the presence of AP would be of great theoretical and practical importance, since accumulation of scientific material allows us to determine risk groups for life-threatening arrhythmias, show their characteristic clinical and electrocardiographic criteria, concentrate the efforts of doctors in managing sick children, and determine thefocus ofpreventive programs. Objective of the study: To study the planimetric parameters of P, the QRS complex and ST– T in standard leads and precordial leads. To study and identify the most significant amplitude–interval parameters of electrocardiography for the manifestation and stabilization ofpremature ventricular excitation. Material and methods of the study: 1,733 children aged 7–14 years (827 girls, 906 boys) were examined. They were selected from the general population of schoolchildren (17,330 children) by simple randomization (A–girls, B–boys), which formed the basis of a 10% sample (Dvoyrin V.V., Klimenkov A.A. 1985). The survey program was carried out in two stages. Stage I was conducted according to the following program: standard survey, objective examination of children and standard survey of parents (Rose questionnaire) for detection of attacks of tachyarrhythmia or its equivalents (feeling of heartbeat, pain, sinking, 98,7:ROTCAFTCAPMI.SECNEICS LACIDEM,5202, yraurbeF,5emuloV gro.srehsilbupcimedaca.www interruptions in the heart area, dizziness, "darkening", "goosebumps" before the eyes, etc.); study of blood pressure (three times), pulsecounting; anthropometric studies and assessment of puberty of the examined children; Electrocardiography (in 12 standard leads). Planimetric method of quantitative analysis of ECG was conducted according to the recommendation of Stomboltsyan R.G. and R.V., Mikhaelyants (method. recommendations Yerevan, 1981). In this case, planimetric indicators of P, QRS complex and ST-T in standard leads and precordial leads were studiedseparately (Fig. 1). The area of ​ ​ the initial and final parts of the ventricular complex of the ECG were calculated separately according to the method: the area was conditionally considered positive(+) if the curve comprising it was above the isoline, negative (–) if it was below this line.The initialpart oftheQRS complex consists ofthealgebraic sumof thearea of​ ​ the Q, R, S waves, and the final part - ST-T - of the algebraic sum of the areas of the ST-T interval and the T wave. Results and discussion. The planimetric area of ​ ​ the QRS complex in sick children with CLC syndrome (Table 1) is increased in many ECG leads, in sick children with CLC syndrome aged 7-10 years it is increased in six leads (50.0%): AVR, AVL and V1-V4, and in sick children aged 11-14 years in five (41.7%) I, AVR, V1-V3. In CLC syndrome, the decrease in ST–T area by the number of ECG leads was pronounced at theage of7–10years (58.3%) and11–14years (75%). Table1. 98,7:ROTCAFTCAPMI.SECNEICS LACIDEM,5202, yraurbeF,5emuloV gro.srehsilbupcimedaca.www These changes were expressed by a decrease in the ST-T area in leads I, II, III, AVF and V4-V6 in sick children aged 7-10 years and in leads I, III, AVL, V3-V6 in children aged 11- 14years. In sick children with the CLC phenomenon (Table 2), an increase in the QRS area was detected in five ECG leads, more pronounced in the right precordial leads V1-V4. In these leads, theSPR forthe QRSarea was a