Journal of cardiovascular electrophysiology
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J. Cardiovasc. Electrophysiol. · Sep 1999
Persistent atrial flutter in patients treated for atrial fibrillation with amiodarone and propafenone: electrophysiologic characteristics, radiofrequency catheter ablation, and risk prediction.
Antiarrhythmic drugs have been reported to promote the conversion of atrial fibrillation to atrial flutter in patients with paroxysmal atrial fibrillation. However, information about the electrophysiologic mechanism and response to radiofrequency ablation of these drug-induced atrial flutters is limited. Furthermore, the determinants of the development of persistent atrial flutter in patients treated for atrial fibrillation with antiarrhythmic drugs are still unknown. ⋯ In patients with atrial fibrillation, persistent typical atrial flutter might occur during antiarrhythmic drug treatment, and atrial enlargement was a risk factor for the development of such an arrhythmia. Radiofrequency ablation and continuation of pharmacologic therapy offered a safe and effective means of achieving and maintaining sinus rhythm.
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J. Cardiovasc. Electrophysiol. · Apr 1999
Comparative StudyAtrial sensing and AV synchrony in single lead VDD pacemakers: a prospective comparison to DDD devices with bipolar atrial leads.
Single lead VDD pacing has offered an alternative to DDD systems in patients with isolated AV block. Up to now, however, the relative performance of these pacemaker systems was not systematically compared. ⋯ With the benefit of a simpler implant procedure, long-term outcome of single lead VDD pacing is equivalent to DDD pacing in patients with AV block and preoperative normal sinus node function.
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J. Cardiovasc. Electrophysiol. · Feb 1999
Comparative StudyPharmacologic cardioversion of chronic atrial fibrillation in the goat by class IA, IC, and III drugs: a comparison between hydroquinidine, cibenzoline, flecainide, and d-sotalol.
Recently, we reported that repetitive induction of atrial fibrillation (AF) in the goat causes electrical remodeling of the atria leading to the development of sustained AF. The aim of the present study was to compare Class IA, IC, and III drugs in their ability to cardiovert chronic AF in remodeled atria. ⋯ In a goat model of sustained AF, Class IA, IC, and III drugs restored sinus rhythm in 67% to 92% of the cases. However, after cardioversion, the atrial wavelength was still abnormally short, and AF was readily inducible in 71% to 100% of the cases.
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J. Cardiovasc. Electrophysiol. · Feb 1999
Comparative StudySodium pentobarbital reduces transmural dispersion of repolarization and prevents torsades de Pointes in models of acquired and congenital long QT syndrome.
Sodium pentobarbital is widely used for anesthesia in experimental studies as well as in clinics, and it is known to prevent the development of torsades de pointes (TdP) in in vivo models of the long QT syndrome (LQTS). ⋯ Our data indicate that pentobarbital reduces TDR in control and under conditions of congenital and acquired LQTS, and suggest that this mechanism may contribute to the ability of the anesthetic to prevent the development of spontaneous as well as stimulation-induced TdP under conditions mimicking LQT2, LQT3, and acquired (drug-induced) forms of the LQTS. The data also serve to illustrate that there are circumstances under which QT prolongation may not be arrhythmogenic.