Circulation. Arrhythmia and electrophysiology
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Circ Arrhythm Electrophysiol · Feb 2012
Comparative StudyFunctional nature of electrogram fractionation demonstrated by left atrial high-density mapping.
Complex fractionated atrial electrograms (CFAE) are targets of atrial fibrillation (AF) ablation. Serial high-density maps were evaluated to understand the impact of activation direction and rate on electrogram (EGM) fractionation. ⋯ The distribution of fractionated EGMs is highly variable, depending on direction and rate of activation (SR versus CSp versus AF). Fractionation in SR and CSp rhythms mostly resulted from wave collision. All sites with continuous fractionation in AF displayed normal voltage in SR, suggesting absence of structural scar. Thus, many fractionated EGMs are functional in nature, and their sites dynamic.
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Circ Arrhythm Electrophysiol · Feb 2012
Comparative StudyAtrial fibrillation after pulmonary transplantation: incidence, impact on mortality, treatment effectiveness, and risk factors.
Atrial fibrillation (AF) is common after thoracic surgery. Limited data exist concerning the incidence of AF, its impact on mortality, the effectiveness of therapy, and the risk factors of AF after pulmonary transplantation. ⋯ AF is fairly common after pulmonary transplantation, transient, and relatively benign. It is not independently associated with increased in-hospital mortality. Most patients return to sinus rhythm before discharge. Age, prior AF, and bilateral transplantation increase the risk of postoperative AF.
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Circ Arrhythm Electrophysiol · Dec 2011
Randomized Controlled Trial Comparative StudyRadiofrequency catheter ablation and antiarrhythmic drug therapy: a prospective, randomized, 4-year follow-up trial: the APAF study.
Information on comparative outcome between radiofrequency catheter ablation (RFA) and antiarrhythmic drugs (AADs) >1 year after randomization is important for clinical decision-making. ⋯ URL: http://www.clinicaltrials.gov. Unique identifier: NCT00340314.
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Circ Arrhythm Electrophysiol · Dec 2011
Randomized Controlled TrialUse of an implantable monitor to detect arrhythmia recurrences and select patients for early repeat catheter ablation for atrial fibrillation: a pilot study.
Catheter ablation of atrial fibrillation (AF) has proved effective in curing highly symptomatic patients with paroxysmal AF. The aim of this prospective, randomized study was to identify the optimal treatment of patients with AF recurrences after the first ablation. ⋯ URL: http://www.clinicaltrials.gov. Unique identifier: NCT01164319.
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Circ Arrhythm Electrophysiol · Dec 2011
Calcium-calmodulin kinase II mediates digitalis-induced arrhythmias.
Digitalis-induced Na(+) accumulation results in an increase in Ca(2+)(i) via the Na(+)/Ca(2+) exchanger, leading to enhanced sarcoplasmic reticulum (SR) Ca(2+) load, responsible for the positive inotropic and toxic arrhythmogenic effects of glycosides. A digitalis-induced increase in Ca(2+)(i) could also activate calcium-calmodulin kinase II (CaMKII), which has been shown to have proarrhythmic effects. Here, we investigate whether CaMKII underlies digitalis-induced arrhythmias and the subcellular mechanisms involved. ⋯ These results show for the first time that CaMKII mediates ouabain-induced arrhythmic/toxic effects. We suggest that CaMKII-dependent phosphorylation of the RyR, resulting in Ca(2+) leak from the SR, is the underlying mechanism involved.