The Complexity of Pediatric Multifocal Atrial Tachycardia and Its Prognostic Factors

Abstract

Background and ObjectivesMultifocal atrial tachycardia (MAT), in general, has a favorable outcome. However, there are insufficient data regarding MAT in a pediatric population. This study sought to determine the clinical course of MAT and identify potential prognostic factors.MethodsThe medical records of MAT patients from 1997–2015 were reviewed. The arrhythmia control rate and factors for unfavorable outcomes were assessed and compared to those in the literature.ResultsOf the 33 included patients (19 boys and 14 girls), 27 were infants less than 1 year of age. The median age at diagnosis was 1.7 months (range, 0 day to 14 years). Fourteen (42%) patients had structural heart disease. Eight (24%) patients had lung disease and 6 (18%) had a syndromic diagnosis belonging to RASopathy. Two patients developed polymorphic ventricular tachycardia, in whom genetic analysis confirmed the presence of the RyR2 mutation several years later. MAT was controlled in 26 patients (84%) within 3.9 months (median; range, 16 days–18.4 years) using an average of 2.4 medications. There were 3 cases of cardiopulmonary mortality. The arrhythmia control rate was higher in the infant group (85%) than in the non-infant group (67%), although this trend was not statistically significant. There was a significantly lower rate of unfavorable outcomes in the idiopathic infant group (n=11) than in the other groups (p=0.008). Considering the findings of previous studies, the mortality rate was significantly higher in patients with structural heart disease than in patients without (21% vs. 5%, p=0.01).ConclusionsMAT usually affects infants and has a favorable prognosis, particularly in the idiopathic infant group. However, in the presence of other comorbidities, MAT may have a variable clinical course.

Ivabradine as a stabilising anti-arrhythmic agent for multifocal atrial tachycardia

“…The vast majority of children with multifocal atrial tachycardia present under a year of age with 24-43% having some associated respiratory illness. 1,2 In a series of 21 patients (median age 1.8 months) with multifocal atrial tachycardia, Bradley reported that 27% had diminished ventricular function with two being critically ill. 1 A variety of anti-arrhythmic medications were utilised with a mixed response though the natural history was fairly favourable with 52% in sinus rhythm within 5 months and 94% asymptomatic and free of any arrhythmia by 60 months. 1 This is in contradistinction to our patient who presented at a slightly older age, 5 months, in extremis and required advanced mechanical circulatory support.…”

Clinical Implication of Multifocal Atrial Tachycardia in Children for Pediatric Cardiologist

“…Baek et al 6) reported the clinical outcome of MAT and potential prognostic factors. Compared to the previous reports, this study has relatively large number of patients and composed of various etiologies despite of limitation of retrospective study from single tertiary center.…”

“…RASopathy has been reported to be associated with high incidence of atrial arrhythmias. 6) 7) MAT in children should be checked the association of RASopathy and vice versa.…”

“…Atrial premature beats, atrial fibrillation (AF), or atrial flutter are known to accompany MAT in both adults and pediatric patients. 5) 6) 8) MAT may be an early manifestation of CPVT and also additional findings of atrioventricular nodal reentrant tachycardia. Phenotypical progression of MAT into CPVT and an association between the RyR2 mutation and AF and ectopic atrial tachycardia have reported.…”

“…Phenotypical progression of MAT into CPVT and an association between the RyR2 mutation and AF and ectopic atrial tachycardia have reported. 6) 9) MAT in young children may be the initial manifestation of a potentially life-threatening arrhythmia of CPVT. Therefore, non-infantile form of MAT with structurally normal hearts might need aggressive evaluations and close follow-up.…”