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Ablating the ventricular insertion of atrio-fascicular mahaim fiber: could be performed safely?

Ducceschi V, Vitale R, Sokola EA, Ottaviano L, Sangiuolo R, Gregorio G - Indian Pacing Electrophysiol J (2009)

Bottom Line: Small, discrete potentials resembling those of Purkinje fiber were found at right ventricular apex.All these potentials showed early activation during tachycardia preceding the QRS onset of various degree.This case report describes catheter ablation of an atriofascicular accessory pathway by targeting its distal (ventricular) insertion site.

View Article: PubMed Central - PubMed

Affiliation: Department of Cardiology, San Luca Hospital, Vallo della Lucania (SA), Italy. valentino.ducceschi@tin.it

ABSTRACT
We report a patient who underwent radiofrequency ablation of the distal insertion of an atrio-fascicular accessory pathway with decremental properties because of inability to map a suitable potential alongside the tricuspid annulus. Small, discrete potentials resembling those of Purkinje fiber were found at right ventricular apex. All these potentials showed early activation during tachycardia preceding the QRS onset of various degree. Pace mapping helped to localize the presumed main distal insertion of the atrio-fascicular accessory pathway in a region where damage of the His-purkinje system may ensue. This case report describes catheter ablation of an atriofascicular accessory pathway by targeting its distal (ventricular) insertion site.

No MeSH data available.


Related in: MedlinePlus

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Mentions: The retrograde atrial activation in the His bundle trace always preceded the others and the atrial activation sequence remained unmodified during the entire recording session even in the presence of TCL changes, this behavior was consistent with true antidromic AV reciprocating tachycardia using the Mahaim fascicle as antegrade limb. V-A prolongation without H-A modification excluded the involvement of a septal concealed accessory pathway as retrograde limb and also ruled out an atrioventriclar nodal reentrant tachycardia with a Mahaim fascicle participation as an innocent "bystander". We may speculate that this behavior probably reflected paroxysmal prolongation of the conduction time or block thorough the RBB next to the insertion of the Mahaim fiber.The ablation procedure was performed using a 7 F 4 mm ablation catheter (Blazer II, Boston Scientific). A careful and complete tricuspid ring mapping was performed in order to record a discrete potential resembling that recorded on His region, the so called Mahaim potential (MP). We failed to identify a discrete potential alongside the entire annulus so we decided to target the ventricular insertion. Given the superior axis of the arrhythmia we deliberately started from the right ventricular apex. Small, discrete potentials resembling those of Purkinje fiber were found near the right ventricular apex, these potentials showed various degrees of early activation during tachycardia and all preceded the His bundle activation. We delivered RF at a site with the apparently most negative local potential-QRS interval but we failed to terminate the arrhythmia. In order to reduce the number of unnecessary RF pulses we decided to perform pace mapping in a region where different sites with early local ventricular activation could be recorded. Pace mapping performed from the recording site of a small potential (SP), presumably the distal RBB, located 35 msec before the tachycardia QRS onset and 40 msec before the HB retrograde activation showed a QRS morphology identical to that observed during tachycardia. (Figures 2,3).


Ablating the ventricular insertion of atrio-fascicular mahaim fiber: could be performed safely?

Ducceschi V, Vitale R, Sokola EA, Ottaviano L, Sangiuolo R, Gregorio G - Indian Pacing Electrophysiol J (2009)

© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2655074&req=5

Mentions: The retrograde atrial activation in the His bundle trace always preceded the others and the atrial activation sequence remained unmodified during the entire recording session even in the presence of TCL changes, this behavior was consistent with true antidromic AV reciprocating tachycardia using the Mahaim fascicle as antegrade limb. V-A prolongation without H-A modification excluded the involvement of a septal concealed accessory pathway as retrograde limb and also ruled out an atrioventriclar nodal reentrant tachycardia with a Mahaim fascicle participation as an innocent "bystander". We may speculate that this behavior probably reflected paroxysmal prolongation of the conduction time or block thorough the RBB next to the insertion of the Mahaim fiber.The ablation procedure was performed using a 7 F 4 mm ablation catheter (Blazer II, Boston Scientific). A careful and complete tricuspid ring mapping was performed in order to record a discrete potential resembling that recorded on His region, the so called Mahaim potential (MP). We failed to identify a discrete potential alongside the entire annulus so we decided to target the ventricular insertion. Given the superior axis of the arrhythmia we deliberately started from the right ventricular apex. Small, discrete potentials resembling those of Purkinje fiber were found near the right ventricular apex, these potentials showed various degrees of early activation during tachycardia and all preceded the His bundle activation. We delivered RF at a site with the apparently most negative local potential-QRS interval but we failed to terminate the arrhythmia. In order to reduce the number of unnecessary RF pulses we decided to perform pace mapping in a region where different sites with early local ventricular activation could be recorded. Pace mapping performed from the recording site of a small potential (SP), presumably the distal RBB, located 35 msec before the tachycardia QRS onset and 40 msec before the HB retrograde activation showed a QRS morphology identical to that observed during tachycardia. (Figures 2,3).

Bottom Line: Small, discrete potentials resembling those of Purkinje fiber were found at right ventricular apex.All these potentials showed early activation during tachycardia preceding the QRS onset of various degree.This case report describes catheter ablation of an atriofascicular accessory pathway by targeting its distal (ventricular) insertion site.

View Article: PubMed Central - PubMed

Affiliation: Department of Cardiology, San Luca Hospital, Vallo della Lucania (SA), Italy. valentino.ducceschi@tin.it

ABSTRACT
We report a patient who underwent radiofrequency ablation of the distal insertion of an atrio-fascicular accessory pathway with decremental properties because of inability to map a suitable potential alongside the tricuspid annulus. Small, discrete potentials resembling those of Purkinje fiber were found at right ventricular apex. All these potentials showed early activation during tachycardia preceding the QRS onset of various degree. Pace mapping helped to localize the presumed main distal insertion of the atrio-fascicular accessory pathway in a region where damage of the His-purkinje system may ensue. This case report describes catheter ablation of an atriofascicular accessory pathway by targeting its distal (ventricular) insertion site.

No MeSH data available.


Related in: MedlinePlus