TY - JOUR T1 - Ventricular tachycardia in the absence of structural heart disease JF - Heart JO - Heart SP - 645 LP - 656 DO - 10.1136/heartjnl-2017-311590 VL - 105 IS - 8 AU - Ammar M Killu AU - William G Stevenson Y1 - 2019/04/01 UR - http://heart.bmj.com/content/105/8/645.abstract N2 - Learning objectivesDetermine the mechanisms of ventricular tachycardia.Recognise the major types of idiopathic ventricular tachycardia.Recognise differences between ventricular tachycardia in patients with inherited arrhythmia syndromes versus those without.The earliest recorded description of ventricular tachycardia (VT) is credited to Sir Thomas Lewis in 19 091. VT is defined as a rhythm originating in the ventricles ≥3 beats duration, with a heart rate of ≥100 beats/minute.2 It is often associated with structural heart disease (SHD), from any disease process affecting ventricular myocardium, including acute or healed myocardial infarction and cardiomyopathies often associated with reduced ventricular ejection fraction and myocardial scar. Less frequently, VT occurs in the absence of SHD. These may be associated with a defined electrophysiological abnormality that is often genetic or may occur with no definable electrical or structural abnormality in which case they are often referred to as idiopathic ventricular arrhythmias (IVT). Detection and characterisation of underlying SHD and recognition of sudden cardiac death (SCD) risk is a critical component of management.In this article, we review salient features of various types of VTs seen in patients with structurally normal hearts, including some associated with inherited arrhythmia syndromes, and provide an overview of therapy. VT can be classified according to its duration and morphology (figure 1):Figure 1 Classification of ventricular tachycardia in the absence of structural heart disease.Duration: VT is sustained if it lasts ≥30 s, causes syncope or haemodynamic compromise requiring therapy. Morphology: Monomorphic VT (MMVT): It has a single QRS morphology, indicating that the sequence of ventricular activation is the same from beat to beat and that a structural substrate or arrhythmia focus is present. Pleomorphic VT:  More than one distinct QRS morphology occurring during same VT episode; it is almost always associated with scar-related VT and is rare in the absence of SHD. Polymorphic VT … ER -