title: Regional myocardial wall thinning at multidetector computed tomography correlates to arrhythmogenic substrate in postinfarction ventricular tachycardia: assessment of structural and electrical substrate.
abstract: BACKGROUND
  A majority of patients undergoing ablation of ventricular tachycardia have implanted devices precluding substrate imaging with delayed-enhancement MRI. Contrast-enhanced multidetector computed tomography (MDCT) can depict myocardial wall thickness with submillimetric resolution. We evaluated the relationship between regional myocardial wall thinning (WT) imaged by MDCT and arrhythmogenic substrate in postinfarction ventricular tachycardia.
  
  
  RESULTS
  We studied 13 consecutive postinfarction patients undergoing MDCT before ablation. MDCT data were integrated with high-density 3-dimensional electroanatomic maps acquired during sinus rhythm (endocardium, 509±291 points/map; epicardium, 716±323 points/map). Low-voltage areas (<1.5 mV) and local abnormal ventricular activities (LAVA) during sinus rhythm were assessed with regard to the WT. A significant correlation was found between the areas of WT <5 mm and endocardial low voltage (correlation-R=0.82; P=0.001), but no such correlation was found in the epicardium. The WT <5 mm area was smaller than the endocardial low-voltage area (54 cm(2) [Q1-Q3, 46-92] versus 71 cm(2) [Q1-Q3, 59-124]; P=0.001). Among a total of 13 060 electrograms reviewed in the whole study population, 538 LAVA were detected and analyzed. LAVA were located within the WT <5 mm (469/538 [87%]) or at its border (100% within 23 mm). Very late LAVA (>100 ms after QRS complex) were almost exclusively detected within the thinnest area (93% in the WT<3 mm).
  
  
  CONCLUSIONS
  Regional myocardial WT correlates to low-voltage regions and distribution of LAVA critical for the generation and maintenance of postinfarction ventricular tachycardia. The integration of MDCT WT with 3-dimensional electroanatomic maps can help focus mapping and ablation on the culprit regions, even when MRI is precluded by the presence of implanted devices.
authors.affiliation: Department of Cardiac Electrophysiology, Hôpital Cardiologique du Haut-Lévêque and Université Victor Segalen Bordeaux II, Institut LYRIC, Equipex MUSIC, Bordeaux, France. yk.komat@gmail.com
authors.forename: Yuki
authors.initials: Y
authors.lastname: Komatsu
authors.forename: Hubert
authors.initials: H
authors.lastname: Cochet
authors.forename: Amir
authors.initials: A
authors.lastname: Jadidi
authors.forename: Frédéric
authors.initials: F
authors.lastname: Sacher
authors.forename: Ashok
authors.initials: A
authors.lastname: Shah
authors.forename: Nicolas
authors.initials: N
authors.lastname: Derval
authors.forename: Daniel
authors.initials: D
authors.lastname: Scherr
authors.forename: Patrizio
authors.initials: P
authors.lastname: Pascale
authors.forename: Laurent
authors.initials: L
authors.lastname: Roten
authors.forename: Arnaud
authors.initials: A
authors.lastname: Denis
authors.forename: Khaled
authors.initials: K
authors.lastname: Ramoul
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Miyazaki
authors.forename: Matthew
authors.initials: M
authors.lastname: Daly
authors.forename: Matthieu
authors.initials: M
authors.lastname: Riffaud
authors.forename: Maxime
authors.initials: M
authors.lastname: Sermesant
authors.forename: Jatin
authors.initials: J
authors.lastname: Relan
authors.forename: Nicholas
authors.initials: N
authors.lastname: Ayache
authors.forename: Steven
authors.initials: S
authors.lastname: Kim
authors.forename: Michel
authors.initials: M
authors.lastname: Montaudon
authors.forename: François
authors.initials: F
authors.lastname: Laurent
authors.forename: Mélèze
authors.initials: M
authors.lastname: Hocini
authors.forename: Michel
authors.initials: M
authors.lastname: Haïssaguerre
authors.forename: Pierre
authors.initials: P
authors.lastname: Jaïs
mesh_terms: D000328:Adult; D000368:Aged; D019571:Arrhythmogenic Right Ventricular Dysplasia / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery; D018780:Body Surface Potential Mapping; D017115:Catheter Ablation / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006329:Heart Conduction System / Q000503:physiopathology* / Q000601:surgery; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D006801:Humans; D021621:Imaging, Three-Dimensional; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods*; D009203:Myocardial Infarction / Q000150:complications* / Q000503:physiopathology; D009206:Myocardium / Q000473:pathology*; D015203:Reproducibility of Results; D012189:Retrospective Studies