title: Acute Cardiac MRI Assessment of Radiofrequency Ablation Lesions for Pediatric Ventricular Arrhythmia: Feasibility and Clinical Correlation.
abstract: BACKGROUND
  Arrhythmia ablation with current techniques is not universally successful. Inadequate ablation lesion formation may be responsible for some arrhythmia recurrences. Periprocedural visualization of ablation lesions may identify inadequate lesions and gaps to guide further ablation and reduce risk of arrhythmia recurrence.
  
  
  METHODS
  This feasibility study assessed acute postprocedure ablation lesions by MRI, and correlated these findings with clinical outcomes. Ten pediatric patients who underwent ventricular tachycardia ablation were transferred immediately postablation to a 1.5T MRI scanner and late gadolinium enhancement (LGE) imaging was performed to characterize ablation lesions. Immediate and mid-term arrhythmia recurrences were assessed.
  
  
  RESULTS
  Patient characteristics include median age 14 years (1-18 years), median weight 52 kg (11-81 kg), normal cardiac anatomy (n = 6), d-transposition of great arteries post arterial switch repair (n = 2), anomalous coronary artery origin post repair (n = 1), and cardiac rhabdomyoma (n = 1). All patients underwent radiofrequency catheter ablation of ventricular arrhythmia with acute procedural success. LGE was identified at the reported ablation site in 9/10 patients, all arrhythmia-free at median 7 months follow-up. LGE was not visible in 1 patient who had recurrence of frequent premature ventricular contractions within 2 hours, confirmed on Holter at 1 and 21 months post procedure.
  
  
  CONCLUSIONS
  Ventricular ablation lesion visibility by MRI in the acute post procedure setting is feasible. Lesions identifiable with MRI may correlate with clinical outcomes. Acute MRI identification of gaps or inadequate lesions may provide the unique temporal opportunity for additional ablation therapy to decrease arrhythmia recurrence.
authors.affiliation: Department of Cardiology, Children's National Health System, Washington, District of Columbia, USA.|Division of Intramural Research, Cardiovascular and Pulmonary Branch, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA.
authors.forename: Elena K
authors.initials: EK
authors.lastname: Grant
authors.affiliation: Department of Cardiology, Children's National Health System, Washington, District of Columbia, USA.
authors.forename: Charles I
authors.initials: CI
authors.lastname: Berul
authors.affiliation: Department of Cardiology, Children's National Health System, Washington, District of Columbia, USA.
authors.forename: Russell R
authors.initials: RR
authors.lastname: Cross
authors.affiliation: Department of Cardiology, Children's National Health System, Washington, District of Columbia, USA.
authors.forename: Jeffrey P
authors.initials: JP
authors.lastname: Moak
authors.affiliation: Department of Cardiology, Children's National Health System, Washington, District of Columbia, USA.
authors.forename: Karin S
authors.initials: KS
authors.lastname: Hamann
authors.affiliation: Department of Cardiology, Children's National Health System, Washington, District of Columbia, USA.
authors.forename: Kohei
authors.initials: K
authors.lastname: Sumihara
authors.affiliation: Department of Cardiology, Children's National Health System, Washington, District of Columbia, USA.
authors.forename: Ileen
authors.initials: I
authors.lastname: Cronin
authors.affiliation: Department of Cardiology, Children's National Health System, Washington, District of Columbia, USA.
authors.forename: Kendall J
authors.initials: KJ
authors.lastname: O'Brien
authors.affiliation: Division of Intramural Research, Cardiovascular and Pulmonary Branch, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA.|Department of Cardiology, Rady Children's Hospital, San Diego, California, USA.
authors.forename: Kanishka
authors.initials: K
authors.lastname: Ratnayaka
authors.affiliation: Department of Cardiology, Children's National Health System, Washington, District of Columbia, USA.|Division of Intramural Research, Cardiovascular and Pulmonary Branch, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA.
authors.forename: Michael S
authors.initials: MS
authors.lastname: Hansen
authors.affiliation: Department of Cardiology, Children's National Health System, Washington, District of Columbia, USA.|Division of Intramural Research, Cardiovascular and Pulmonary Branch, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA.
authors.forename: Peter
authors.initials: P
authors.lastname: Kellman
authors.affiliation: Department of Cardiology, Children's National Health System, Washington, District of Columbia, USA.
authors.forename: Laura J
authors.initials: LJ
authors.lastname: Olivieri
mesh_terms: D000293:Adolescent; D000367:Age Factors; D017115:Catheter Ablation / Q000009:adverse effects; D002648:Child; D002675:Child, Preschool; D005240:Feasibility Studies; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging; D008297:Male; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012008:Recurrence; D012307:Risk Factors; D017180:Tachycardia, Ventricular / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D013997:Time Factors; D016896:Treatment Outcome
keywords: ablation; arrhythmia; congenital heart disease; electrophysiology; magnetic resonance imaging