P606Arrhythmias in repaired pediatric and adolescent fallot tetralogy, correlation with cardiac MRI parameters

Funding Acknowledgements: Pediatric and Radiodiagnosis departments, faculty of medicine, Cairo University OnBehalf: N/A Background tetralogy of fallot (TOF) is a common congenital cyanotic heart disease in which arrhythmias could develop even after successful operative repair. Pulmonary regurgitation (PR) and consequently, right ventricular dilatation develop in many cases.Purpose: to study the incidence of arrhythmias and correlate it with MRI parameters in this group of patients. Methodology: Cross sectional descriptive study was conducted on 32 cases after successful surgical repair. Transthoracic colour Doppler echocardiography, 24 hours Holter monitoring and functional cardiac MRI for assessment of pulmonary regurgitant fraction (PR fraction), ventricular volume and function were performed. Cases were classified according to right ventricular end diastolic volume index (RVEDVI) into 2 groups with cut off value 150 ml/m2, the value above which pulmonary valve replacement was recommended . Results: Mean age of the studied cases was (12.96 ± 3.38) years, mean age at time of surgical repair was (34.23± 22.1) months, and mean duration postoperatively was (121.72± 41.03) months, range 30-192 (2.5-16 years). 18 cases(56%) had RVEDVI ≥150 ml/m2, PR fraction was significantly higher in cases of increased RVEDVI(p 0.007), left ventricular ejection fraction (LVEF) was significantly lower in the same group (p 0.002).Arrhythmias were detected in 18 cases (56%), most common of which was infrequent supraventricular ectopy, no significant difference in incidence of arrhythmias between the 2 groups (p 1), no significant correlation between arrhythmias and increased RVEDVI( p value 0.76, r 0.05). Arrhythmias were significantly more common in older age group (p0.001) with no difference between cases with and without arrhythmias in RVEDVI (p 0.56), PR fraction (p 0.5) Left ventricular end diastolic volume index LVEDVI(p 0.25) RVEF (p 0.06) or LVEF(p 0.06) conclusion: Holter detected arrhythmias after successful surgical repair of TOF significantly were associated with increased postoperative duration but not related to cardiac MRI parameters