title: Enhanced infarct border zone function and altered mechanical activation predict inducibility of monomorphic ventricular tachycardia in patients with ischemic cardiomyopathy.
abstract: OBJECTIVE
  To prospectively determine whether mechanical behavior of left ventricular wall segments that contain different degrees of scar tissue and are located at different distances from the interface between infarcted and noninfarcted myocardial tissue can help predict inducibility of monomorphic ventricular tachycardia (VT) in patients with ischemic cardiomyopathy.
  
  
  METHODS
  This HIPAA-compliant study was institutional review board approved; written informed consent was obtained from all patients. Forty-six patients (36 men, 10 women; mean age +/- standard deviation, 61.6 years +/- 11.9) with prior myocardial infarction (MI) and left ventricular dysfunction were referred for defibrillator implantation and underwent an electrophysiologic examination and tagged contrast-enhanced magnetic resonance (MR) imaging. Peak circumferential shortening strain (Ecc) and time to peak Ecc were measured in 12 segments from short-axis sections. Remote, adjacent, and border zones were defined according to increasing proximity to the MI. Patients in whom monomorphic VT could be induced (ie, inducible patients) were considered positive for inducibility. Relationships between inducibility of monomorphic VT, peak Ecc, and time to peak Ecc were analyzed with one-way analysis of variance and Bonferroni test.
  
  
  RESULTS
  Inducible patients had more infarcted and border zone sectors and a shorter time to peak Ecc than did noninducible patients in the border zone and adjacent and infarcted regions (P < .001). Peak Ecc in the border zone of inducible patients (-11.42% +/- 0.46 [standard error]) was greater than that in noninducible patients (-10.18% +/- 0.38; P < .05). Ratio of Ecc in border zone and in remote regions was greater (P < .05) in inducible patients than in noninducible patients (1.31 +/- 0.27 vs 0.64 +/- 0.13, respectively).
  
  
  CONCLUSIONS
  Enhanced border zone function defined as greater Ecc and earlier time to peak Ecc showed positive correlation to VT inducibility in patients with prior MI and left ventricular dysfunction.
authors.affiliation: Division of Cardiology, Johns Hopkins Hospital, 600 N Wolfe St, Blalock 524, Baltimore, MD 21287, USA.
authors.forename: Verônica Rolim S
authors.initials: VR
authors.lastname: Fernandes
authors.forename: Katherine C
authors.initials: KC
authors.lastname: Wu
authors.forename: Boaz D
authors.initials: BD
authors.lastname: Rosen
authors.forename: André
authors.initials: A
authors.lastname: Schmidt
authors.forename: Albert C
authors.initials: AC
authors.lastname: Lardo
authors.forename: Nael
authors.initials: N
authors.lastname: Osman
authors.forename: Henry R
authors.initials: HR
authors.lastname: Halperin
authors.forename: Gordon
authors.initials: G
authors.lastname: Tomaselli
authors.forename: Ronald
authors.initials: R
authors.lastname: Berger
authors.forename: David A
authors.initials: DA
authors.lastname: Bluemke
authors.forename: Eduardo
authors.initials: E
authors.lastname: Marbán
authors.forename: João A C
authors.initials: JA
authors.lastname: Lima
mesh_terms: D005260:Female; D006352:Heart Ventricles / Q000473:pathology* / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications* / Q000473:pathology / Q000503:physiopathology; D017202:Myocardial Ischemia / Q000150:complications*; D011446:Prospective Studies; D017180:Tachycardia, Ventricular / Q000209:etiology*; D018487:Ventricular Dysfunction, Left / Q000150:complications*