Journal of cardiovascular electrophysiology
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J. Cardiovasc. Electrophysiol. · May 2000
Comparative StudyDependence of electrogram duration in right posteroseptal atrium and atrium-pulmonary vein junction on pacing site: mechanism and implications regarding atrioventricular nodal reentrant tachycardia and paroxysmal atrial fibrillation.
The fractionated atrial electrogram, a signal helpful in identifying the target site for radiofrequency catheter ablation of the slow AV nodal pathway, is considered to arise from nonuniform anisotropic electrical activity. However, the effects of pacing sites and radiofrequency ablation on these electrograms are not clear. Similarly, the nature of the fractionated atrial electrogram in the atrium-pulmonary vein junction has yet to be determined. ⋯ These findings suggest that the fractionated atrial electrograms in the right posteroseptal atrium and ostium of left or right superior pulmonary veins are potentially consistent with nonuniform anisotropic propagation. Alternations of electrogram characteristics after successful radiofrequency ablation of the slow AV nodal pathway may arise from the changes of nonuniform anisotropic activity in the right posteroseptal atrium.
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J. Cardiovasc. Electrophysiol. · May 2000
Comparative StudySpatial and temporal heterogeneity of depolarization and repolarization may complicate implantable cardioverter defibrillator therapy in Brugada syndrome.
Dynamic variations in electrophysiologic phenomena inherent to the Brugada syndrome may complicate therapy with implantable cardioverter defibrillators (ICDs). ⋯ These findings demonstrate that, in Brugada syndrome, spontaneous or ajmaline-induced changes in the surface ECG may be paralleled by significant variations in the right ventricular endocardial electrogram that may result in ICD malfunction. Implantation of a left ventricular epicardial lead for sensing and pacing may be the ultimate successful approach in certain patients. To assure proper ICD function, ajmaline testing during ICD implantation appears to be helpful.