Idiopathic ventricular tachycardia in patients with an anatomically normal heart is a distinct entity whose management and prognosis differs from ventricular tachycardia associated with structural heart disease. 

The tachycardia's QRS morphology on surface electrocardiogram (ECG) predicts the site of origin and is commonly classified as right ventricular tachycardia or left ventricular tachycardia.

Patients generally tolerate the tachycardia and sudden cardiac death is rare in this patient population.

Observed Ventricular tachycardias (VT) are usually related to structural heart disease. However in 10% of patients with VT, no structural heart disease, metabolic/electrolyte abnormalities or long QT syndrome can be found. These arrhythmias have been called idiopathic VT. They consist of various subtypes defined by their clinical presentation (repetitive monomorphic tachycardias, exercise-induced sustained ventricular arrhythmias) and/or their underlying mechanism (adenosine sensitive triggered arrhythmias, intrafascicular or interfascicular re-entrant arrhythmias). 

These arrhythmias have certain anatomic locations within the heart and manifest specific electrocardiographic (ECG) patterns which help to identify their site of origin. A characteristic common to most cases of idiopathic ventricular tachycardia is good prognosis, although patients should continue to have periodic cardiac follow-ups to rule out latent progressive heart disease such as arrhythmogenic right ventricular dysplasia or other forms of cardiomyopathies.

This review summarises common forms of idiopathic ventricular tachycardias that the general cardiologist should know (Table 1).

Referecne: https://www.escardio.org/Journals/E-Journal-of-Cardiology-Practice/Volume-8/How-to-recognise-and-manage-idiopathic-ventricular-tachycardia