Heart rhythm : the official journal of the Heart Rhythm Society
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The right ventricular outflow tract (RVOT) is the most common site of origin of ventricular arrhythmias (VAs) in patients with idiopathic VAs. A left bundle branch block, inferior axis morphology arrhythmia is the hallmark of RVOT arrhythmias. VAs from other sites of origin can mimic RVOT VAs, and ablation in the RVOT typically fails for these VAs. ⋯ In patients in whom ablation of a VA with an RVOT-like appearance fails, mapping of the pulmonary artery, the aortic cusps, the epicardium, the left ventricular outflow tract, and the aortic cusps will help identify the correct site of origin. The 12-lead ECG is helpful in differentiating these VAs from RVOT VAs.
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Multicenter Study Clinical Trial
Atrioventricular delay programming and the benefit of cardiac resynchronization therapy in MADIT-CRT.
The optimal atrioventricular pacing delay (AVD) in cardiac resynchronization therapy (CRT) remains to be determined. ⋯ Our findings indicate that in MADIT-CRT programming, the CRT AVD <120 ms was associated with a greater clinical and echocardiographic response to CRT.
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Little is known about the clinical and prognostic impact of early repolarization (ER) on patients with Brugada syndrome (BrS), especially those with documented ventricular fibrillation (VF). ⋯ The prevalence of ER in inferolateral leads was high and an especially persistent form of ER was associated with a worse outcome in BrS patients with documented VF.
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Low-voltage termination of ventricular tachycardia (VT) and atrial fibrillation has shown promising results; however, the mechanisms and full range of applications remain unexplored. ⋯ A novel 2-stage low-voltage defibrillation protocol using the excitable gap extent to time multiple stimuli defibrillated VF with the least energy by first converting VF into VT and then terminating VT.
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Conducting channels within scars form the substrate for infarct-related ventricular tachycardia (VT) and are targeted during catheter ablation. Whether the amount of left ventricular scar (LVS) affects outcomes after VT ablation is not known. ⋯ LVS burden derived from 12-lead ECGs is a significant and independent predictor of mortality and clinical outcomes in subjects with infarct-related VT.