Prevalence of preoperative arrhythmias in children with delayed treatment of severe congenital heart disease.

AIM: Our aim was to determine the real importance of rhythm and conduction disorders in children with unoperated severe congenital heart disease. METHODS: Consecutive children with delayed treatment of severe congenital heart disease were prospectively studied for the occurrence of arrhythmias before any invasive investigation or surgical procedure was performed. RESULTS: All 168 children were in sinus rhythm. One hundred and fifty-eight patients (94%) had no significant preoperative findings. One child with double discordance had an intermittent complete atrioventricular block, and another one had a long QT syndrome. Children with severe ventricular dysfunction had paroxysmal atrioventricular re-entry tachycardia in 3 cases and abnormally frequent premature ventricular complexes in 3 other cases. Children with severe left atrial dilatation had periods of atrial ectopic tachycardia in one case and atrial fibrillation in another case. CONCLUSIONS: The prevalence of rhythm and conduction disorders is relatively low in children with delayed treatment of severe congenital heart disease. Only those with congenital heart disease classically combined with such disorders and those with prolonged severe ventricular dysfunction and/or atrial dilatation are at risk of developing significant arrhythmias and should undergo a preoperative assessment of arrhythmias.