Europace : European pacing, arrhythmias, and cardiac electrophysiology : journal of the working groups on cardiac pacing, arrhythmias, and cardiac cellular electrophysiology of the European Society of Cardiology
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Catheter-based radiofrequency ablation with pulmonary vein (PV) isolation has emerged as an effective therapy for patients with symptomatic atrial fibrillation. Real-time intracardiac echocardiography with two-dimensional and Doppler colour flow imaging can facilitate left heart ablation procedures. ⋯ It has a critical role for guiding transseptal catheterization, assisting placement of mapping and ablation catheters, and allows for titration of energy delivery. More importantly, it allows identification and potential reduction of procedural complications including damage to intracardiac structures, left atrial thrombus formation, PV stenosis, and pericardial effusion during left heart ablation.
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Identification of atypical atrial flutter (AFL) (non-cavo-tricuspid isthmus-dependent) prior to the electrophysiology laboratory is potentially useful because it allows appropriate procedural planning and enables discussion of the likely success rates and risks of the procedure with the patient. Typical counterclockwise AFL has a stereotypic appearance, the electrocardiogram (ECG) is predictive of the diagnosis in the majority of cases, and ablation procedures are associated with a high degree of safety and success. ⋯ Targeting these complex and often multiple re-entrant circuits is aided by expertise and use of electroanatomic mapping systems. This review will address whether there are clues from the 12-lead ECG which assist in the localization of AFL circuits.
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One of the most feared potential adverse effects of many drugs is life threatening or fatal arrhythmia--particularly torsade de pointes (TdP) ventricular tachycardia in conjunction with QT prolongation. To fully understand the implications of QT prolongation, it is essential to have an understanding of the ion currents that comprise repolarization and their relation to electrophysiological abnormalities associated with TdP. Also, the QT interval is subject to patient-specific and sometimes idiosyncratic variability. ⋯ Repolarization reserve is also discussed. Suggestions for refining the understanding of drug-induced QT prolongation, TdP, and shortcomings of some current definitions are outlined. We speculate on possible future developments in understanding this relationship.
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Review
Drug-induced QT-interval prolongation and proarrhythmic risk in the treatment of atrial arrhythmias.
Despite the large number of available antiarrhythmic agents, significant QT-interval prolongation and risk of severe proarrhythmia, including torsade de pointes, limit pharmacological opportunities in the management of atrial arrhythmias. The risk of proarrhythmia has been demonstrated in class I and class III drugs, but significant variability has been observed between agents of the same class. ⋯ Interestingly, less proarrhythmic potential is seen or anticipated with agents that are able to block multiple ion channels and those with atrial selectivity, despite moderate QT prolongation. This observation has helped steer the development of newer drugs, with some promising preliminary results.
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The aim of this article is to provide a comprehensive description of interventions that can improve outcomes in adults with sudden cardiac death. The new American Heart Association 2005 Guidelines introduced a number of changes for the initial management of cardiorespiratory arrest based on new data that accumulated over the last 5 years. ⋯ The new guidelines for CPR have focused on early defibrillation, uninterrupted compressions, complete decompression, fewer ventilations, and simplification and uniformity of the process.