The substrate and ablation of ventricular tachycardia in patients with nonischemic cardiomyopathy.

The term "nonischemic cardiomyopathy" (NICM) designates a myocardial disease characterized by mechanical and/or electrical dysfunction in the absence of significant coronary artery disease, valvular heart disease, hypertension, or congenital heart disease. Although sustained ventricular tachycardia (VT) occurs in only 5% of patients with NICM, it is an important cause of sudden cardiac death. In this review we summarize the current understanding of the anatomic and electrophysiologic substrates of VT in the different types of NICM. In addition, we discuss recent progress and experience with catheter ablation of VT in these patients.