title: Diffuse ventricular fibrosis is a late outcome of tachycardia-mediated cardiomyopathy after successful ablation.
abstract: BACKGROUND
  Successful arrhythmia ablation normalizes ejection fraction (EF) in tachycardia-mediated cardiomyopathy, but recurrent heart failure and late sudden death have been reported. The aim of this study was to characterize the left ventricle (LV) of tachycardia-mediated cardiomyopathy patients long after definitive arrhythmia cure.
  
  
  RESULTS
  Thirty-three patients with a history of successfully ablated incessant focal atrial tachycardia 64±36 months prior, and 20 healthy controls were recruited. At ablation, 18 patients had EF<50% (AT-low EF) that recovered within 3 months from 37±12 to 56±4% (P<0.001), whereas 15 patients had EF>55% (AT-normal EF). No subjects had EF of 50% to 55%. Subjects underwent echocardiography with speckle tracking and contrast-enhanced cardiac MRI with ventricular T1 mapping as an index of diffuse fibrosis. Contrast-enhanced cardiac MRI was performed using a clinical 1.5-T scanner and 0.2 mmol/kg gadolinium-diethylene triamine penta-acetic acid for contrast. Subject characteristics were similar across the 3 groups. Compared with AT-normal EF patients and controls, AT-low EF patients had lower EF (60±6 versus 64±4 and 65±4%; P<0.05), greater indexed LV end-diastolic volume (102±34 versus 84±14 and 85±16 mL/m(2); P<0.05), and greater indexed LV end-systolic volume (41±11 versus 31±7 and 30±8 mL/m(2); P<0.01) on contrast-enhanced cardiac MRI. Compared with controls, AT-low EF patients had reduced global LV corrected T1 time (442±53 versus 529±61; P<0.05) consistent with diffuse fibrosis.
  
  
  CONCLUSIONS
  Tachycardia-mediated cardiomyopathy patients exhibit differences in LV structure and function including diffuse fibrosis long after arrhythmia cure, indicating that recovery is incomplete.
authors.affiliation: Alfred Hospital and Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia.
authors.forename: Liang-han
authors.initials: LH
authors.lastname: Ling
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Kalman
authors.forename: Andris H
authors.initials: AH
authors.lastname: Ellims
authors.forename: Leah M
authors.initials: LM
authors.lastname: Iles
authors.forename: Caroline
authors.initials: C
authors.lastname: Medi
authors.forename: Craig
authors.initials: C
authors.lastname: Sherratt
authors.forename: David M
authors.initials: DM
authors.lastname: Kaye
authors.forename: James L
authors.initials: JL
authors.lastname: Hare
authors.forename: Peter M
authors.initials: PM
authors.lastname: Kistler
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Taylor
mesh_terms: D000328:Adult; D000368:Aged; D009202:Cardiomyopathies / Q000209:etiology* / Q000473:pathology / Q000503:physiopathology; D017115:Catheter Ablation; D003287:Contrast Media; D015150:Echocardiography, Doppler; D005260:Female; D005355:Fibrosis; D019786:Gadolinium DTPA; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology; D006801:Humans; D016014:Linear Models; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012307:Risk Factors; D013318:Stroke Volume; D013617:Tachycardia, Supraventricular / Q000150:complications / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D013997:Time Factors; D016896:Treatment Outcome; D016277:Ventricular Function, Left; D020257:Ventricular Remodeling; D014739:Victoria
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA
keywords: MRI; T1 mapping; ablation; cardiomyopathies; tachycardia