title: Supraventricular tachycardia during the first year of life: is subclinical inflammation the trigger?
abstract: BACKGROUND
  Neutrophil/lymphocyte ratio (NLR) and red cell distribution width (RDW) may be associated with the onset of arrhythmias in adults, thus underlining a possible inflammatory etiology. Paroxysmal supraventricular tachycardia (SVT) is the most frequent pathological tachycardia in childhood.
  
  
  OBJECTIVE
  To verify NLR and RDW levels in a group of children (<1 year) affected by SVT with a structurally normal heart and without fever or inflammatory diseases; to compare NLR and RDW before and after SVT resolution, to verify whether the latter was related with the reduction in inflammatory state; to identify - in SVT subtypes caused by a reentry mechanism - an NLR and RDW cutoff point beyond which adenosine was ineffective in preventing SVT recurrence.
  
  
  METHODS
  Eighteen SVT patients were recruited (mean age 18.9 ± 3.2 days; 50% males) and compared with 18 healthy peers.
  
  
  RESULTS
  NLR was higher in SVT group than in controls (p < 0.03). A significant difference was revealed between NLR values obtained on admission and at discharge (p < 0.05). On the contrary, no significant differences were found for RDW. It was not possible to identify NLR or RDW cutoffs capable of predicting SVT recurrence. However, all patients featuring SVT recurrence following adenosine injection presented with a lymphocyte count >6000/mm3.
  
  
  CONCLUSIONS
  Elevated NLR is associated with an increased risk of SVT during the first year of life, while its decline looks like to lead the SVT resolution. A subclinical inflammatory status, as assessed by lymphocytes count, influences SVT recurrence. These results provide further support for an inflammatory etiology of SVT in babies.
authors.affiliation: a Department of Medical Sciences "M. Aresu" , University of Cagliari , Cagliari , Italy.
authors.forename: Pier Paolo
authors.initials: PP
authors.lastname: Bassareo
authors.affiliation: b Department of Pediatrics and Clinical Medicine, Section of Neonatal Intensive Care Unit , University of Cagliari , Cagliari , Italy.
authors.forename: Vassilios
authors.initials: V
authors.lastname: Fanos
authors.affiliation: c Pediatric Cardiology Unit , AOU Sassari , Sassari , Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: Pala
authors.affiliation: a Department of Medical Sciences "M. Aresu" , University of Cagliari , Cagliari , Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Antonucci
authors.affiliation: b Department of Pediatrics and Clinical Medicine, Section of Neonatal Intensive Care Unit , University of Cagliari , Cagliari , Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Neroni
authors.affiliation: d Pediatric Clinic, University of Sassari , Sassari , Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Antonucci
authors.affiliation: a Department of Medical Sciences "M. Aresu" , University of Cagliari , Cagliari , Italy.
authors.forename: Guseppe
authors.initials: G
authors.lastname: Mercuro
mesh_terms: D004909:Erythrocyte Indices; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007249:Inflammation / Q000150:complications; D018655:Lymphocyte Count; D008297:Male; D012189:Retrospective Studies; D013617:Tachycardia, Supraventricular / Q000097:blood / Q000276:immunology*
keywords: Supraventricular tachycardia; adenosine; children; inflammation; neutrophil/lymphocyte ratio; red cell distribution width