Infarct morphology identifies patients with substrate for sustained ventricular tachycardia

J Am Coll Cardiol. 2005 Apr 5;45(7):1104-8. doi: 10.1016/j.jacc.2004.12.057.


Objectives: We sought to evaluate whether infarct size characterization by cardiac magnetic resonance imaging (MRI) is a better predictor of inducible ventricular tachycardia (VT) than left ventricular ejection fraction (LVEF).

Background: Inducibility of VT at electrophysiologic study (EPS) and low LVEF can identify patients with a substrate for VT. Magnetic resonance imaging has been shown to identify, with high precision, areas of myocardial infarction and may therefore be a better tool to evaluate for a substrate for VT.

Methods: We studied 48 patients with known coronary artery disease who were referred for EPS using cine and gadolinium-enhanced MRI. Wall motion and infarct characteristics were determined blindly and compared among patients with no inducible ventricular arrhythmias (n = 21), those with inducible monomorphic VT (MVT, n = 18), and those with either inducible polymorphic VT or ventricular fibrillation (n = 9).

Results: Patients with MVT had larger infarcts than patients who did not have inducible arrhythmias (mass: 49 +/- 5 g [SE] vs. 28 +/- 5 g, p < 0.005; surface area: 172 +/- 15 cm(2) vs. 93 +/- 14 cm(2), p < 0.0005). Patients with polymorphic VT/fibrillation had intermediate values (mass: 36 +/- 7 g; surface area: 115 +/- 22 cm(2)). Ejection fraction was inversely related to infarct mass and surface area, with R(2) values ranging from 0.21 to 0.27. Logistic regression and receiver-operating characteristic analysis demonstrated that infarct mass and surface area were better predictors of inducibility of MVT than LVEF.

Conclusions: Infarct surface area and mass, as measured by cardiac MRI, are better identifiers of patients who have a substrate for MVT than LVEF. Further evaluation of infarct size characterization by cardiac MRI as a predictor of sudden cardiac death is warranted.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Female
  • Humans
  • Magnetic Resonance Imaging / methods*
  • Male
  • Middle Aged
  • Myocardial Infarction / complications
  • Myocardial Infarction / pathology*
  • Myocardial Infarction / physiopathology
  • Predictive Value of Tests
  • ROC Curve
  • Sensitivity and Specificity
  • Stroke Volume
  • Tachycardia, Ventricular / complications
  • Tachycardia, Ventricular / pathology*
  • Tachycardia, Ventricular / physiopathology