How ECG indicators of hypertrophy correspond to echocardiographic findings: Interim results from Hand aufs Herz Study

Abstract Background Electrocardiography (ECG) is widely used in cardiovascular screening of healthy school-aged children, however pediatric hypertrophy criteria have limited accuracy due to physiological variation such as age, sex and physical maturation. Echocardiography remains the structural reference, yet data directly comparing ECG hypertrophy patterns with echocardiography confirmed ventricular hypertrophy (VH) in healthy children remains scarce. Purpose This analysis examined how often ECG patterns suggesting left or right VH occur in healthy children and whether they correspond to echocardiography confirmed VH. Methods In this prospective cross-sectional study, 976 healthy school-aged children aged 8– 19 years (47.5% female; mean age 13.35 ± 2.29 years) underwent standardized 12-lead ECG and transthoracic echocardiography as part of school-based cardiovascular screening. Participants with missing data for sex or interventricular septal thickness were excluded prior to statistical testing. For this analysis we focused on VH patterns on the ECG, defined accordingly to pediatric ECG criteria, and VH confirmed on echocardiography defined as Interventricular Septal Diastole (IVSD) z-score over + 2. Each examination was performed and interpreted by pediatric cardiologists. Statistical analyses were performed in RStudio, v4.5.1. Student’s t-tests and Fisher’s exact tests for continuous and categorical variables, respectively, were used to compare group differences between females and males. Results ECG patterns suggestive of VH were present in 80 children (8.2%) and occurred significantly more common in males (71 males, 9 females; p 0.001). The mean age did not differ significantly between children with and without ECG hypertrophy patterns (13.46 ± 2.03 vs 13.34 ± 2.31 years; p = 0.66). Echocardiographic VH was identified in 3 children (0.3%): 2 cases of left VH (both male) and 1 case of right VH (female). None of the children with ECG patterns suggestive of VH had it confirmed on echocardiography. Conversely, the 3 children with echocardiography confirmed VH showed no ECG evidence of hypertrophy. Thus, there was no overlap between ECG- detected hypertrophy patterns and echocardiography confirmed VH (p = 1.0). Conclusion ECG hypertrophy patterns were uncommon, true VH was very rare and did not correlate with ECG findings. These results emphasize that pediatric ECG hypertrophy criteria lack the specificity required for reliable structural screening and may contribute to unnecessary referrals and anxiety if used as a standalone screening tool. Accurate assessment with echocardiography is therefore essential to prevent overdiagnosis of VH in pediatric cardiovascular prevention programs.