Prevalence and factors associated with Electrocardiography (ECG) abnormalities among children with congenital heart disease attending Mulago Hospital, Kampala Uganda

Abstract

Background: In Uganda, few children with congenital heart disease (CHD) benefit from early corrective cardiac surgery. These children are at high risk of having malnutrition, heart failure and electrolyte imbalances; factors which increase the risk of cardiac conduction abnormalities. We aimed to determine the prevalence and factors associated with electrocardiography (ECG) abnormalities among children with CHD attending Mulago Hospital.

Methods: This was a cross-sectional descriptive study carried out from August 2013 to March 2014 at Mulago Hospital. Standard 12-lead ECGs were performed on 194 children with CHD (age range 10days-15years) who had been consecutively enrolled into the study. ECG abnormalities sought were; abnormal rate, PR interval, QTc interval and arrhythmias. Data was analysed using SPSS 16.0 and multivariate analysis done for variables with P value ≤ 0.2.

Results: Out of 194 children studied, 77 (39.7%) had at least one of the key ECG abnormalities. Prolonged PR interval was the commonest abnormality; 44/194 (22.7%) followed by sinus tachycardia 17/194 (8.8%). Prevalence of prolonged QTc interval was 13/194 (6.7%) and that of arrhythmias was 9/194 (4.5%). Factors associated with prolonged PR interval were digoxin use (OR 3.399, 95% CI 1.168-9.887) and age 5years and below (OR 0.163, 95% CI 0.067-0.400). Factors associated with arrhythmias and sinus tachycardia included electrolyte imbalances, wasting, anaemia and heart failure. No factor was associated with prolonged QTc interval.

Conclusion: Prolonged PR interval, arrhythmias, sinus tachycardia and prolonged QTc interval are common abnormalities among children with CHD. These are associated with digoxin use, child’s age, electrolyte imbalances, wasting, anaemia and heart failure.