Idiopathic Ventricular Tachycardias for the EM Physician

Written by Pendell Meyers, reviewed by Steve Smith and Scott Weingart“Idiopathic ventricular tachycardias” refer to a group of tachydysrhythmias originating below the AV node and bundle of His but differing in etiology, prognosis, and treatment compared to classic ventricular tachycardia (VT). The name “idiopathic” is becoming more and more inappropriate, as various specific subgroups and specific etiologies are being discovered, including right ventricular outflow tract VT, fascicular VT, and bundle branch reentrant VT. To understand these entities one must first understand the differences between classic VT and idiopathic VTs.Classic VT is by far the most common cause of wide complex regular tachycardia. It originates in (usually pathologic) myocardium, which is associated with advanced age, cardiovascular disease, structural heart disease and/or ischemia. Classic VT is associated with the prognosis of its underlying etiology, and is generally considered to have a significant rate of deterioration and hemodynamic compromise, largely due to the poor underlying myocardial function. On EKG, Classic VT tends to have longer QRS duration and a wider, less organized conduction morphology as compared with idiopathic VT, reflecting the key concept that classic VT does not usually originate in or near the intrinsic conduction system whereas many of the “idiopathic” VTs do. Unlike “idiopathic” VT, classic VT is more likely to show moderately specific signs such as AV d...
Source: Dr. Smith's ECG Blog - Category: Cardiology Authors: Source Type: blogs