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VA Block (va + block)
Selected AbstractsParoxysmal Supraventricular Tachycardia with Persistent Ventriculoatrial BlockJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 1 2003BERNHARD STROHMER M.D. Supraventricular Tachycardia with VA Conduction Block. We report the case of a 64-year-old patient with paroxysmal supraventricular tachycardia and persistent VA block. Induction and maintenance of tachycardia occurred without apparent activation of the atria. Diagnostic characteristics were most compatible with AV nodal reentrant tachycardia (AVNRT). Automatic junctional tachycardia and orthodromic nodoventricular or nodofascicular reentry tachycardia were considered in the differential diagnosis. Upper common pathway block during AVNRT may be explained by either intra-atrial conduction block or purely intranodal confined AVNRT. The arrhythmia was cured by a typical posteroseptal ablation approach guided by slow pathway potentials. [source] Analysis of Atrioventricular Nodal Reentrant Tachycardia with Variable Ventriculoatrial Block: Characteristics of the Upper Common PathwayPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 4 2009KENJI MORIHISA M.D. Background: The precise nature of the upper turnaround part of atrioventricular nodal reentrant tachycardia (AVNRT) is not entirely understood. Methods: In nine patients with AVNRT accompanied by variable ventriculoatrial (VA) conduction block, we examined the electrophysiologic characteristics of its upper common pathway. Results: Tachycardia was induced by atrial burst and/or extrastimulus followed by atrial-His jump, and the earliest atrial electrogram was observed at the His bundle site in all patients. Twelve incidents of VA block: Wenckebach VA block (n = 7), 2:1 VA block (n = 4), and intermittent (n = 1) were observed. In two of seven Wenckebach VA block, the retrograde earliest atrial activation site shifted from the His bundle site to coronary sinus ostium just before VA block. Prolongation of His-His interval occurred during VA block in 11 of 12 incidents. After isoproterenol administration, 1:1 VA conduction resumed in all patients. Catheter ablation at the right inferoparaseptum eliminated antegrade slow pathway conduction and rendered AVNRT noninducible in all patients. Conclusion: Selective elimination of the slow pathway conduction at the inferoparaseptal right atrium may suggest that the subatrial tissue linking the retrograde fast and antegrade slow pathways forms the upper common pathway in AVNRT with VA block. [source] Radiofrequency Catheter Ablation of an Incessant Ventricular Tachycardia Following Valve SurgeryPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 1 2002THORSTEN LEWALTER LEWALTER, T., et al.: Radiofrequency Catheter Ablation of an Incessant Ventricular Tachycardia Following Valve Surgery. Sustained monomorphic ventricular tachycardia (VT) after valve surgery represents a clinical entity with different tachycardia mechanisms. This case report describes an incessant VT after tricuspid and aortic valve replacement that did not respond to antiarrhythmic drug treatment. The tachycardia exhibited VA block and a right bundle branch block pattern with left-axis deviation, suggesting ventricular excitation via the left posterior fascicle. The electrophysiological study was limited by the prosthetic tricuspid and aortic valve replacement, therefore a transseptal approach was necessary to obtain access to the ventricular myocardium. Radiofrequency catheter ablation was performed in the proximal left bundle or distal His region with termination of the incessant VT followed by complete AV block. After pacemaker implantation using a transvenous right atrial and an epicardial ventricular lead, no VT reoccurrence could be documented. [source] | ||||||||||