Experience of using 3-day monitoring of the Holter electrocardiogram with telemetry (3G) on the example of examination of children with hypertrophic cardiomyopathy
Authors:   National Medical Research Center for Children's Health, Moscow, Russian Federation, Akhmedova E.E. , Kozhevnikova O.V. ,   National Medical Research Center for Children's Health, Moscow, Russian Federation, Gandaeva L.A. ,   National Medical Research Center for Children's Health, Moscow, Russian Federation, Basargina E.N. ,   National Medical Research Center for Children's Health, Moscow, Russian Federation, Silnova I.V. ,   National Medical Research Center for Children's Health, Moscow, Russian Federation, Abashidze E.A. ,   National Medical Research Center for Children's Health, Moscow, Russian Federation, Barsky V.I. ,   National Medical Research Center for Children's Health, Moscow, Russian Federation, Rodionova A.M. ,   National Medical Research Center for Children's Health, Moscow, Russian Federation, Rakhimova A.N. ,   National Medical Research Center for Children's Health, Moscow, Russian Federation, Chernyshеva Yu.А. ,   National Medical Research Center for Children's Health, Moscow, Russian Federation, Blazhievskaya T.O. ,   National Medical Research Center for Children's Health, Moscow, Russian Federation
Published: February 2024

Objective. To evaluate the results of 72-hour monitoring of Holter electrocardiograms with telemetry in children with hypertrophic cardiomyopathy (HCM). Patients and methods. A randomized retrospective study of 55 children with the confirmed diagnosis of HCM was conducted on the basis of the Federal State Autonomous Institution of the Ministry of Health of Russian Federation "National Children Medical Research Center"; all patients were hospitalized in the cardiology department for the examination and treatment in the period 2021–2023. The study included 33 boys and 22 girls aged 6 to 17.8 years; age and documented functional limitations in both groups were comparable. All patients underwent electrocardiography (ECG) on the 12-channel electrocardiograph; 3-channel 3-day monitoring of Holter electrocardiograms with telemetry using the Astrocard-Telemetry 3G complex (Meditek, Russia); magnetic resonance imaging (MRI) of the heart with intravenous contrast. Parents of 43 patients filled out questionnaires identifying direct and indirect signs of sleep disorders. The obtained data were presented in fractions, as well as as M ± m; minimum, Q1, Q3, maximum; and the Kendall rank correlation coefficient and the Friedman criterion were calculated daily. The differences were considered significant at p < 0.05. The work has been approved by an independent local ethics committee. All parents (or legal representatives) of the children signed the voluntary informed Results. 12-channel ECG revealed various and non-specific disorders (arrhythmias, signs of overload of the heart chambers) in 50 (90.9%) patients. Long-term (3-day) Holter monitoring revealed practically no significant differences in the mean values of the studied indicators between days; by the 3rd day of the study, two trends were revealed: an increase in the average number of episodes of ventricular tachycardia (p = 0.058) and an elongation of the QTc interval in boys (p = 0.053). The significant decrease in heart rate was recorded in girls on the 3rd day of the study (p = 0.011). According to the results of MRI, intramyocardial fibrosis was detected in 37 (67.3%) cases: in 23 (69.7%) boys and 14 (63.6%) girls. In 16 (29.1%) patients, the volume of myocardial lesion was ≥10%. Direct and/or indirect signs of respiratory disorders during sleep were recorded in 28 (65.1%) children. In children with signs of sleep disorders, significant positive correlations were found with the number of supraventricular and ventricular extrasystoles and episodes of ventricular tachycardia. Signs of an increased risk of sudden vascular death were recorded in 8 (14.5%) children. Conclusion. Long-term (3-day) Holter monitoring of electrocardiograms is well adapted to children; all major rhythm disturbances were detected during the first 24 hours. Prolongation of the study may be recommended to solve certain clinical problems (diagnosis of syncopal conditions, paroxysms of unclear etiology, sleep apnea). In children with HCM, it is necessary to identify direct and indirect signs of sleep disorders that have significant correlations with cardiac arrhythmias, including those that are an integrative indicator of the risk of sudden cardiac death. Key words: sudden cardiac death, hypertrophic cardiomyopathy, children, multi-day monitoring of electrocardiogram with telemetry, rhythm disturbances, sleep disorders