Heart Rate Variability Analysis of Patients With Idiopathic Left Ventricular Outflow Tract Tachycardia

Identification of Unusual Reentry Circuit Sites of Nonischemic Ventricular Outflow Tract Tachycardia

“…It is rare for VT originating from the ventricular OT and ASOV to be due to reentry. The majority are believed to be due to triggered activity or abnormal automaticity 1–3,5,14 . Many of these arise from the right ventricular OT.…”

“…The majority are believed to be due to triggered activity or abnormal automaticity. [1][2][3]5,14 Many of these arise from the right ventricular OT. In this paper, we reported observations from 6 (11.7%) nonischemic heart disease patients in whom VT was inducible and terminable by programmed stimulation, out of 51 patients who displayed VT believed to be of ventricular OT origin based on 12-lead ECG morphology during VT. Entrainment pacing within the ventricular OT and/or the ASOV led us to believe that reentry was the mechanism of VT in all 6 patients.…”

“…VT can also be classified according to mechanism, namely, triggered activity, abnormal automaticity, or reentry. The majority of VT arising from the ventricular outflow tract (OT) regions is idiopathic in origin, and is caused by focal mechanisms (triggered activity or abnormal automaticity), rather than reentry 1‐3 . Radiofrequency current ablation of such VT foci, localized by activation mapping and pace mapping during electrophysiological study, has been reported to result in a complete cure from VT in over 90% of patients thus treated 4‐7 .…”

Idiopathic Outflow Tract Tachycardias

“…VT can happen either during the exercise or recovery phases of the stress test [23]. Limited studies on the heart rate variability in patients with OT-VT suggest that activation of sympathetic tone plays an important role in the occurrence of VT originating from the outflow tract [29,30].…”

Afterdepolarizations Promote the Transition From Ventricular Tachycardia to Fibrillation in a Three-Dimensional Model of Cardiac Tissue.

“…[10][11][12][13][14][15] The EADs are classified into phase-2 and phase-3 EADs. The phase-2 EADs can be induced experimentally by various conditions, even in the absence of calcium overload.…”