Heart rhythm : the official journal of the Heart Rhythm Society
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Randomized Controlled Trial Multicenter Study
Response of right ventricular size to treatment with cardiac resynchronization therapy and the risk of ventricular tachyarrhythmias in MADIT-CRT.
Cardiac resynchronization therapy (CRT) is increasingly recognized for its ability to reduce ventricular tachyarrhythmias, possibly associated with left ventricular reverse remodeling, but the role of the right ventricle (RV) in this process has not been examined. ⋯ Our findings suggest that the RV may have an important role in determining the antiarrhythmic effect of CRT independent of the effect of the device on the left ventricle.
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Long QT syndrome type 13 (LQT13) is caused by loss-of-function mutation in the KCNJ5-encoded cardiac G-protein-coupled inward rectifier potassium channel subtype 4 protein. The electrocardiographic (ECG) features of LQT13 are not described yet. ⋯ This study demonstrates for the first time the ECG features of patients with LQT13. Our data suggest that QTpeak intervals and T-wave morphology combination score may be the better parameters than the corrected QT interval to predict the phenotype-genotype relationship in patients with LQT13.
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Pulmonary vein isolation by cryoballoon ablation is an accepted method of treating atrial fibrillation. Little data exist regarding factors affecting late electrical reconnection of pulmonary veins following cryoballoon ablation. ⋯ Balloon warming time, vein occlusion score, and pulmonary vein size predict pulmonary vein reconnection. Balloon warming time was the most important predictive factor, and the manipulation of balloon warming may be a novel therapeutic strategy for improving outcomes of cryoballoon ablation for atrial fibrillation.
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Randomized Controlled Trial
Clinical outcomes with synchronized left ventricular pacing: analysis of the adaptive CRT trial.
Acute studies have suggested that left ventricular pacing (LVP) may have benefits over biventricular pacing (BVP). The adaptive cardiac resynchronization therapy (aCRT) algorithm provides LVP synchronized to produce fusion with the intrinsic activation when the intrinsic atrioventricular (AV) interval is normal. The randomized double-blind adaptive cardiac resynchronization therapy trial demonstrated noninferiority of the aCRT algorithm compared to echocardiography-optimized BVP (control). ⋯ Higher %sLVP was independently associated with superior clinical outcomes. In patients with normal AV conduction, the aCRT algorithm provided mostly sLVP and demonstrated better clinical outcomes compared to echocardiography-optimized BVP.