lectrocardiographic recognition and ablation of outflow tract entricular tachycardia

a Outflow tract tachycardias comprise a subgroup of idioathic ventricular tachycardias (VTs) that occur in the abence of structural heart disease. The arrhythmia mechanism ppears to be calcium-dependent triggered activity, and no iscrete anatomic abnormalities have been identified. In our xperience, most of these outflow tract tachycardias origiate from a fairly narrow anatomic zone. These arrhythmias riginate in an arc-like fashion from the right ventricular RV) inflow region to the anteroseptal aspect of the right entricular outflow tract (RVOT) under the pulmonic valve. he arc then extends leftward to include the cusp region of he aortic valve and the anterior left ventricle (LV) in front f the aortic valve, both endocardially and epicardially, and hen further extends toward the aorto–mitral continuity and uperior mitral annulus. Most outflow tract tachycardias riginate in perivalvular tissue, which may be anatomically redisposed to fiber disruption that enhances arrhythmogensis. In addition, the proximity of the outflow tract to the picardial fat pads containing the ganglionated plexuses and he unique response to exercise and hormonal changes sugest that the autonomic nervous system also plays a role in his arrhythmogenesis. Because outflow tract tachycardias end to occur in the absence of structural heart disease and re focal in origin, the 12-lead ECG recorded during VT is precise localizing tool. In this review, we highlight the CG features of outflow tract tachycardias that aid in loalization and describe our approach to mapping and ablaion.