Electrocardiographic Localization of Ventricular Tachycardia in Patients with Structural Heart Disease.

The 12-lead electrocardiogram (ECG) during ventricular tachycardia (VT) in patients with structural heart disease contains information that helps to narrow the electrophysiologist's search for target sites for ablation. Although replacement of myocardium by scar might be expected to produce variability in the spread of activation during VT, nonetheless reasonably consistent ECG patterns exist that can regionalize exit sites from VT circuits in up to 75% of cases. Most experience with this comes from patients with prior myocardial infarction, but a growing body of data exists concerning patients with nonischemic cardiomyopathies.