Prognosis of ventricular premature contractions (VPCS) in children and adolescents without structural cardiac abnormalities and chronic disease: A clinical follow up study

Objective: We aimed to evaluate the effects of demographic features, VPS frequency, origin and character on prognosis of VPCs in healthy children diagnosed with ventricular premature contraction. Patients: We retrospectively examined the patients who were diagnosed with VPC and followed up for at least 2 years in the Pediatric Cardiology clinic of Akdeniz University Faculty of Medicine between 2017 and 2020. The patients who had been diagnosed with cardiac abnormality or chronic disease or missing or insufficient follow-up laboratory data were excluded from the study. Methods: The surface ECG findings, 24-hour ambulatory Holter ECG (AHE) recording data, Echocardiography findings, exercise test and cardiac magnetic resonance imaging results were obtained by the medical information database of our hospital. Symptoms related to arrhythmia and physical examination findings on admission were recorded. Echocardiography, surface and 24-hour ambulatory Holter ECG (AHE) examination were performed in all patients at the first admission and these initial laboratory findings were compared with follow up data. The origins and characteristics of VPCs were analyzed based on surface ECG data. The characteristic of VPCs was classified according to Lown classifications. The frequency of VPCs, distribution of VPC frequency in sleep/wake periods, presence of non-sustained VT were evaluated 24-hour ambulatory Holter ECG method. The frequency of VPCs was defined as the ratio of the VPC number to the total heart beat (VPC/THB) per day. According to the frequency of VPCs, the patients were categorized into three groups: rare VPC (VPC was equal or less than 5% of THB), medium frequency VPC (VPC was between 5 and 10 % of THB), and frequent VPC (VPC was equal or more than 10% of THB). If the change in VPC burden in 24-hour AHE at follow-up was less than 10%, it was defined as unchanged. If the change was more than 10%, it was defined as increased or decreased in VPC burden at follow-up. We also evaluated the effects of the drugs given to patients or interventional therapies on prognosis. Results: 73 patients were included in this study. The mean age of the patient was 11.1 years (lower and upper limit: 11 months-17.8 years) on admission, a female/male ratio was 0.78 and the mean follow-up period was 27 months (max: 40 months). 54.8% of patients had complaints related to arrhythmia on admission. The most common complaint was chest pain and recorded in 18 patients (24.7%) of cases. Physical examination revealed pathological findings in 38.4% of patients. The most common physical finding was arrhythmia and detected by auscultation in 28.8% of them. Based on surface ECG records, the VPC axis was located inferiorly in 89% of cases and located superiorly in 11% of the patients. VPCs originated from the left ventricle and right ventricle in 15.1% and 84.9% of cases, respectively. The mean QTc duration of patients with right ventricular origin VPC was significantly higher than that of patients with left ventricular origin (p = 0.003). While 16.4% of our patients showed polymorphic VPC features, 83.6% presented monomorphic VPC features. In our study group, 42.5% of the patients had couplet VPC and 9.6% (seven patients) had ventricular tachycardia. According to 24-hour AHE recordings, 58.9% of the patients were defined as rare VPC, 15.1% as medium frequency VPC, and 26% as frequent VPC. When all were evaluated, simple VPC was detected in 38 (52.1%) patients and complex VPC in 35 (47.9%) patients in our study group. An exercise test was performed in 39 patients (53.4%) in our study group and only three (7.7%) were positive. Cardiac magnetic resonance imaging (CMRI) performed in nine (12.3%) patients due to a suspicion of Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC). There was a slight increase in trabeculation in the right ventricular wall in one patient and mild steatosis in the right ventricular myocardium in another patient. The pathological CMRI findings were detected in only two patients in our study group. The mean EF value at follow up was not significantly different than that measured at initial examination. During the follow-up period, there was no significant increase in left ventricular dimension, and the heart failure did not occur. The frequencies of VPCs reduced significantly at follow up (6.74 ± 8.23 % versus 2.88 ± 4.85 %), (p<0.001). The VPCs were more frequent in 74% of the patients during awake and in 26% of the patients during sleep. 24-hour AHE records at follow-up showed that the frequency of VPCs was decreased in 49 patients (67.1%), increased in 14 patients (19.2%) and unchanged in 10 patients (13.7%). VPCs completely disappeared in 37 patients (50.7%) during follow-up. The decrease in frequency of VPCs in the follow-up was higher ratio seen in patients (69.4 versus 54.5 %) with VPC originating from the right ventricle. The increase in frequency of VPCs in the follow-up was higher ratio seen in patients (27.3 versus 19.4 %) with a left ventricular origin. However, the differences between them were not statistically significant. While the frequency of trigeminy VPC at the first admission was found to be significantly higher in patients who increased in frequency of VPC during follow-up (p=0.039). The frequency of bigeminy VPC was found to be significantly higher at the first admission in patients who decreased in the frequency of VPC (p=0.031). In addition, the decrease in VPC/THB ratio at follow-up was significantly more common in patients with moderate and frequent VPC at initial examination when compared to patients with rare VPC at initial examination (p=0.005). However, the complete recovery of VPCs was significantly higher in patients with rare VPC (p=0.045). There was no significant relationship between VPC morphology, presence of VT, ventricular origin and character of VPCs and the change in VPC/THB ratio and disappearance of VPCs in the follow-up. 25 (34.2%) patients were given pharmacological treatment. In our study, there was no significant difference when the changes of VPCs frequency in the follow-up were compared between the groups with and without pharmacological treatment. In addition, five (6.8%) patients underwent catheter ablation and complete recovery was achieved in four of these patients. Conclusion: This study showed that idiopathic ventricular extra beats are more commonly shown in inferior axis with right ventricular origin in children with structurally normal hearts. The age and gender of the patients, VPC frequency in 24-hour AHE monitorisation, distribution of VPC frequency in sleep/wake periods, presence of non-sustained VT and ventricular origins of VPCs have been shown not to affect the prognosis; and even in children with complex VPC, all patient have a very good clinical course. The drug therapy may provide symptomatic improvement, however it doesn't affect prognosis. The catheter ablation may provide successful results in appropriate cases. The prognosis of VPCs in children with structurally normal hearts is favorable and the patient families should be relieved on this issue. Additionally, children can be approved to participate in sports activities after evaluations