Risk factors for development of ventricular tachycardia in patients with ventricular premature contraction with a structurally normal heart

BACKGROUND: We examined risk factors for development of ventricular tachycardia (VT) in pediatric patients with ventricular premature contractions (VPCs) and a structurally normal heart. METHODS: The subjects were 81 844 first graders and 88 244 seventh graders of Kagoshima City School‐based cardiovascular screening (SCV‐screening) between 2001 and 2015. We retrospectively reviewed the clinical data of students who were diagnosed as having VPC. RESULTS: Ventricular premature contractions were observed in 134 first graders (0.16%) and 270 seventh graders (0.31%). On the screening electrocardiograms (ECGs), 43 patients (11%) showed bi‐/trigemini, three patients (0.7%) showed a couplet, and one patient showed VT. We obtained 166 patients' follow‐up information and evaluated 59 patients (36%) as improved, 97 patients (58%) as no change, and 10 patients (6%) as worsened (couplets, five; triplets, two; VT, three). We assumed that these worsened patients have risk factors for development of VT. Comparing the findings of SCV‐screening ECGs of risk patients with the others, a significant difference was observed only in the number of VPCs (per 10 seconds) (mean ± SD; 4.3 ± 2.6 vs 1.8 ± 1.4, P < .0001). A logistic regression analysis revealed that the number of VPCs was significant (P < .001, odds ratio; 2.01, 95% confidence intervals; 1.46‐2.93). Receiver operating characteristics analysis showed an adequate cut‐off number of three VPCs for the risk, the sensitivity was 89% and the specificity was 77%. CONCLUSIONS: Of the patients with VPC and a structurally normal heart, a few patients developed VT. Careful observation is important in patients who had three or more VPCs on SCV‐screening ECG.