It is the underlying substrate determining ventricular tachycardia (VT) characteristics. Understanding the VT substrate in different diseases and individual patients is crucial. Catheter ablation... Show moreIt is the underlying substrate determining ventricular tachycardia (VT) characteristics. Understanding the VT substrate in different diseases and individual patients is crucial. Catheter ablation can abolish the substrate and plays an increasingly important role in the treatment of VT. This thesis studies the determinants for the substrate causing VT, the VT characteristics and outcome specifically after catheter ablation in patients with structural normal hearts, after myocardial infarction and with cardiomyopathies. Furthermore it is shown that integration of imaging, like magnetic resonance imaging and computed tomography, with catheter mapping is feasible. The use of new mapping criteria and integration of imaging techniques may facilitate successful catheter ablation. Show less