Prevalence, types and factors associated with late arrhythmias following paediatric open-heart surgery of cardiac anomalies among children attending the Uganda Heart Institute

Abstract

Globally, the prevalence of pediatric cardiac anomalies requiring open-heart surgery is on the increase, with improved access to diagnosis and cardiac surgeries in low- and middle-income countries. Late arrhythmias, defined in this study as those occurring more than 30 days post-surgery, have been noted as a potential complication following these procedures. However, the prevalence, types, and risk factors associated with late arrhythmias after open heart surgery for congenital and acquired heart diseases in Ugandan patients remain unexplored. This study aims to address this gap by investigating these key aspects in the Ugandan context. Objective: To determine the prevalence, types, and factors associated with late arrhythmias among children attending the outpatient department at the Uganda Heart Institute, following open-heart surgery performed either within or outside Uganda. Methods: This was a retrospective chart review that included children aged 1 month to <18 years with cardiac anomalies who had undergone open-heart surgery in or outside Uganda and were >30 days post-surgery. Children who attended Uganda Heart Institute OPD between January 2023 and June 2024 were considered. The surgical diagnosis and patients' biodata were collected from registers, and the surgery date was obtained from their inpatient charts and pre-referral charts then Parents/guardians were contacted to confirm the surgery location and any additional comorbidities. The latest visit data, including anthropometry, ECG, heart rate, SpO2, were then retrieved from the Uganda Heart Institute's registers and ECHO (from an electronic data base), using a pre-tested questionnaire. Wasting was categorized using WHO as weight for length/height Z score < 5 years and BMI for age Z score ≥5years, moderate acute malnutrition was ≥-3SD to <-2SD while severe acute malnutrition was <-3SD. The data was entered into Epidata version 3.1 and exported to Stata version 15 for bivariate and multivariate analyses to assess factors associated with late arrhythmias. Results: The study included 174 children, 48.3% female and 51.7% male, with a median age of 5 years (IQR: 4 to 26 months). Moderate acute malnutrition was present in 19.5% of the children, and 4.6% had severe acute malnutrition. Most children (72.4%) underwent cardiac surgery before age 5, with 60.9% having surgery in India and 24.7% in Uganda. The most common procedure was ventricular septal defect repair (29.9%) followed by Tetralogy of Fallot repair (24.7%) and total anomalous pulmonary venous return repair was the least common (0.7%). Late arrhythmias occurred in 56.3% of the children, including first-degree heart block (3.1%), complete RBBB (43.9%), partial RBBB (51%) and LBBB (2%) Factors significantly associated with late arrhythmias were children aged 4–12 years [aOR 2.44 {95% CI: 1.15-5.19., p=0.020], wasting [aOR 3.93 {95% CI: 1.64-9.42}, p = 0.002)] and history of TOF repair [aOR 5.51, {95% CI: 2.03-14.97}, p=0.001]. Conclusion and Recommendation: Late arrhythmias, particularly RBBB, are common after open-heart surgery in Ugandan children with cardiac anomalies. School age, wasting, and TOF repair increase the risk. Early surgery and nutritional support, are recommended.

Keywords: Late arrhythmias; open heart surgery; Cardiac anomalies; Paediatrics; Children.