Circulation. Arrhythmia and electrophysiology
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Circ Arrhythm Electrophysiol · Mar 2017
Comparative StudyFascicular Ventricular Tachycardia Originating From Papillary Muscles: Purkinje Network Involvement in the Reentrant Circuit.
Verapamil-sensitive fascicular ventricular tachycardia (FVT) has been demonstrated to be a reentrant mechanism using the Purkinje network as a part of its reentrant circuit. Although the papillary muscles (PMs) are implicated in arrhythmogenic structure, reentrant FVT originating from the PMs has not been well defined. ⋯ Reentrant circuit of verapamil-sensitive FVT can involve the Purkinje network lying around the PMs. PM-FVT is a distinct entity that is characterized by distinctive electrocardiographic characteristics and less sensitivity to verapamil administration compared with common type FVT. Ablation targeting the mid-diastolic Purkinje potentials around the PMs during tachycardia can be effective in suppressing this arrhythmia.
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Circ Arrhythm Electrophysiol · Mar 2017
Comparative StudyEffects of Late Sodium Current Blockade on Ventricular Refibrillation in a Rabbit Model.
After defibrillation of initial ventricular fibrillation (VF), it is crucial to prevent refibrillation to ensure successful resuscitation outcomes. Inability of the late Na+ current to inactivate leads to intracellular Ca2+ dysregulation and arrhythmias. Our aim was to determine the effects of ranolazine and GS-967, inhibitors of the late Na+ current, on ventricular refibrillation. ⋯ Late Na+ current inhibition during long-duration VF reduces the susceptibility to subsequent refibrillation, partially by mitigating dysregulation of intracellular Ca2+. These results suggest the potential therapeutic use of ranolazine and GS-967 and call for further testing in cardiac arrest models.
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Circ Arrhythm Electrophysiol · Dec 2016
Extracorporeal Membrane Oxygenation for Hemodynamic Support of Ventricular Tachycardia Ablation.
We report the experience in a cohort of consecutive patients receiving extracorporeal membrane oxygenation during catheter ablation of unstable ventricular tachycardia (VT) at our center. ⋯ Ablation of unstable VTs can be safely supported by extracorporeal membrane oxygenation, which allows rhythm stabilization with low procedure mortality, bridging decompensated patients to permanent LVAD or heart transplantation. Successful ablation is associated with better outcomes than unsuccessful ablation.
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Circ Arrhythm Electrophysiol · Dec 2016
Incidence, Risk Factors, and Outcome of Life-Threatening Ventricular Arrhythmias in Giant Cell Myocarditis.
Ventricular tachyarrhythmias are characteristic of giant cell myocarditis, but their true incidence, predictors, and outcome are unknown. ⋯ In giant cell myocarditis, the risk of life-threatening ventricular arrhythmias exceeds 50% at 5 years from admission, being related to the presenting clinical manifestation and markers of myocardial injury and scarring.
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Circ Arrhythm Electrophysiol · Oct 2016
Non-Reentrant Fascicular Tachycardia: Clinical and Electrophysiological Characteristics of a Distinct Type of Idiopathic Ventricular Tachycardia.
The most common form of idiopathic Purkinje-related ventricular tachycardia (VT) is the reentrant type. We describe the clinical and electrophysiological characteristics of focal non-reentrant fascicular tachycardia. ⋯ Among idiopathic VT cases referred for ablation, 2.8% were focal non-reentrant fascicular tachycardia, which had distinct clinical characteristics and usually originated from the left posterior fascicle, and less commonly from the left anterior fascicle and right ventricular Purkinje network. Catheter ablation is effective, whereas pacemap-guided approach is less efficacious.