Particular Aspects of Cardiac Rhythm Disorders in Symptomatic Children and Adolescents

Background: Cardiac arrhythmias in children and adolescents may present with nonspecific symptoms such as precordial pain, palpitations, and syncope. We evaluated the clinical characteristics and rhythm findings of symptomatic pediatric patients and examined cross-sectional associations between reported symptoms and selected rhythm diagnoses, with particular attention to the diagnostic and management yield of ambulatory Holter monitoring. Because symptom timing is not always captured during diagnostic monitoring, associations between reported symptoms and detected rhythm abnormalities must be distinguished from temporal symptom–rhythm correlation and causation. Methods: We conducted an observational study of 119 children and adolescents aged 1–18 years, who were evaluated at a tertiary pediatric hospital for symptoms potentially suggestive of cardiac rhythm abnormalities. Data included demographic characteristics, clinical symptoms, personal and family history, resting electrocardiography, ambulatory Holter monitoring, and exercise testing where clinically indicated. The primary analysis was cross-sectional. Because symptom timing during ambulatory monitoring was not recorded, the study was not designed to establish temporal symptom–rhythm correlation or causality. Descriptive analyses were performed for the final 119-participant cohort. Selected symptom–rhythm associations were evaluated using the contingency table methods with odds ratios (ORs), 95% confidence intervals (CIs), and Fisher’s exact tests where appropriate. Holm’s adjustment was applied to the prespecified family of reconstructed symptom–rhythm comparisons. Results were interpreted according to both statistical evidence and effect-size precision. Results: The cohort comprised 119 participants, including 75 females (63.0%) and 44 males (37.0%). The most frequently reported symptoms were precordial pain (105/119, 88.2%), palpitations (80/119, 67.2%), and syncope or lipothymia (39/119, 32.8%). A family history of sudden cardiac death was reported by 28 participants (23.5%). Forty-two participants (35.3%) had a normal resting ECG, while 77 (64.7%) underwent ambulatory Holter monitoring. Among those undergoing Holter monitoring, 65/77 (84.4%) had rhythm abnormalities detected exclusively by ambulatory monitoring and not identified on the resting ECG. Holter findings resulted in at least one documented management change in 38/77 participants (49.4%). Management categories were not mutually exclusive and included lifestyle or activity adjustment in 21 participants, initiation of antiarrhythmic therapy in 19, medication monitoring in 19, and targeted cardiac imaging, including cardiac magnetic resonance imaging, in 5. In this cross-sectional analysis, reported syncope/lipothymia was strongly associated with the presence of complete atrioventricular block (10/39 [25.6%] versus 1/80 [1.3%]; OR 27.24, 95% CI 3.34–222.29; Fisher’s exact p < 0.001; Holm’s adjusted p approximately 0.0004). The unadjusted association between syncope/lipothymia and the WPW-labelled diagnosis did not remain statistically significant after Holm’s adjustment. No statistically significant associations were identified between syncope/lipothymia and PSVT or VT. Conclusions: In this pediatric cohort, ambulatory Holter monitoring identified rhythm abnormalities not detected on resting ECG in a substantial proportion of monitored participants and resulted in documented changes in clinical management in approximately half of those monitored. Reported syncope/lipothymia was strongly associated with the presence of complete atrioventricular block in the reconstructed cross-sectional analysis. Because symptom timing during monitoring was not recorded, these findings do not establish that the detected rhythm abnormalities caused the reported symptoms or that symptoms predict future rhythm outcomes. Further studies using prospectively defined symptom–rhythm event recording and longitudinal follow-up are needed to evaluate temporal correlation and prognosis.