Association Between Frequent PVCs and Myocardial Strain in Children with Structurally Normal Hearts

Background/Objectives: While premature ventricular contraction (PVC) burden is clearly linked to cardiomyopathy in adults, its association with ventricular dysfunction in children remains less well established. This study investigated the myocardial effects of a PVC burden greater than 5% and its potential predictive factors in a pediatric population. Methods: The study enrolled 23 children aged 5–18 years with a PVC burden >5% on 24 h Holter monitoring, who had no chronic systemic illness, congenital or acquired heart disease, or known family history of cardiomyopathy or sudden cardiac death, along with 33 age-matched healthy controls. Data on demographic characteristics, anthropometric measures, clinical findings, and laboratory results were obtained. Twelve-lead electrocardiography, exercise testing using the Bruce protocol, 24 h Holter monitoring, and echocardiographic assessments—including conventional, tissue Doppler, and both segmental and global strain analyses—were performed and compared between the patient and control groups. Results: In the patient group, left ventricular isovolumetric relaxation time (IVRT) was prolonged, and the myocardial performance index (MPI) was higher compared with the controls (p < 0.001, p = 0.004). Longitudinal strain analysis revealed a significant reduction in global longitudinal strain (GLS) (p = 0.035). In addition, significantly lower segmental longitudinal strain values were observed in the basal anterolateral, basal inferolateral, and basal anterior segments, as well as a reduction in apical two-chamber GLS (p = 0.002, p = 0.002, p = 0.003, and p = 0.014, respectively). Circumferential strain was also significantly reduced in the basal anteroseptal, basal anterior, basal inferolateral, and mid anteroseptal segments, as well as in the basal, mid, and global averages (p = 0.003, p = 0.003, p = 0.026, p = 0.003, p = 0.006, p = 0.022, and p = 0.017, respectively). PVC burden on Holter monitoring was positively correlated with the global strain values, indicating less negative strain with increasing PVC burden. Conclusions: In children with structurally normal hearts and a PVC burden exceeding 5%, TDI and strain imaging revealed subtle alterations in diastolic function and myocardial deformation despite preserved ejection fraction. These findings suggest that frequent PVCs may be associated with early myocardial alterations and highlight the potential utility of advanced echocardiographic techniques in this population.