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A narrow QRS complex Tachycardia with an apparently concentric retrograde atrial activation sequence.

Arias MA, Castellanos E, Puchol A, Pachon M - Indian Pacing Electrophysiol J (2009)

Bottom Line: The retrograde atrial activation sequence constitutes an initial important clue to elucidate the tachycardia mechanism during diagnostic electrophysiological testing in patients with supraventricular tachycardia.However, in some cases its correct analysis is challenging.

View Article: PubMed Central - PubMed

Affiliation: Cardiac Arrhythmia and Electrophysiology Unit. Department of Cardiology. Hospital Virgen de la Salud. Toledo. Spain. maapalomares@secardiologia.es

ABSTRACT
The retrograde atrial activation sequence constitutes an initial important clue to elucidate the tachycardia mechanism during diagnostic electrophysiological testing in patients with supraventricular tachycardia. However, in some cases its correct analysis is challenging.

No MeSH data available.


Related in: MedlinePlus

Schematic representation of the retrograde atrial activation during orthodromic atrioventricular reentrant tachycardia using a left lateral accessory pathway with concomitant presence of conduction block through the mitral isthmus. A: Explains tracings recorded when a quadripolar catheter was placed in the proximal third of the CS; and B: when a decapolar one was advanced more distally (distal bipole at anterolateral position). Atrial activation wavefront proceeds from the atrial insertion of the accessory pathway along the superior mitral annulus to the His region and then spread to right atrium and proximal to distal CS. Two possibilities might explain why CS bipoles 5-6 to 9-10 are activated from distal (5-6) to proximal (9-10), in panel B: 1-. existence of conduction delay (not complete block) through the mitral isthmus; 2-. activation front through the lateral aspect of the blocked isthmus turned around the left-sided pulmonary veins and then activates the posterolateral to posteroseptal aspect of the CS. MI = mitral isthmus; AP = accessory pathway.
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Figure 3: Schematic representation of the retrograde atrial activation during orthodromic atrioventricular reentrant tachycardia using a left lateral accessory pathway with concomitant presence of conduction block through the mitral isthmus. A: Explains tracings recorded when a quadripolar catheter was placed in the proximal third of the CS; and B: when a decapolar one was advanced more distally (distal bipole at anterolateral position). Atrial activation wavefront proceeds from the atrial insertion of the accessory pathway along the superior mitral annulus to the His region and then spread to right atrium and proximal to distal CS. Two possibilities might explain why CS bipoles 5-6 to 9-10 are activated from distal (5-6) to proximal (9-10), in panel B: 1-. existence of conduction delay (not complete block) through the mitral isthmus; 2-. activation front through the lateral aspect of the blocked isthmus turned around the left-sided pulmonary veins and then activates the posterolateral to posteroseptal aspect of the CS. MI = mitral isthmus; AP = accessory pathway.

Mentions: The present case shows two interesting aspect: a) intrinsic conduction block (or delay) non-related to prior ablation in the mitral isthmus might exist to some extent in some patients; and b) conduction block in the mitral isthmus in the presence of a laterally located left-sided accessory pathway may alter the atrial activation sequence during either orthodromic atrioventricular reentrant tachycardia or ventricular pacing conducting through the accessory pathway (Figure 3). A detailed mapping along the entire mitral annulus can help us to reveal the exact location of an accessory pathway for patient with previous failed ablation attempt of a left lateral accessory pathway or as in our case, when electrophysiological findings are not totally comprehensible despite an adequate initial evaluation.


A narrow QRS complex Tachycardia with an apparently concentric retrograde atrial activation sequence.

Arias MA, Castellanos E, Puchol A, Pachon M - Indian Pacing Electrophysiol J (2009)

Schematic representation of the retrograde atrial activation during orthodromic atrioventricular reentrant tachycardia using a left lateral accessory pathway with concomitant presence of conduction block through the mitral isthmus. A: Explains tracings recorded when a quadripolar catheter was placed in the proximal third of the CS; and B: when a decapolar one was advanced more distally (distal bipole at anterolateral position). Atrial activation wavefront proceeds from the atrial insertion of the accessory pathway along the superior mitral annulus to the His region and then spread to right atrium and proximal to distal CS. Two possibilities might explain why CS bipoles 5-6 to 9-10 are activated from distal (5-6) to proximal (9-10), in panel B: 1-. existence of conduction delay (not complete block) through the mitral isthmus; 2-. activation front through the lateral aspect of the blocked isthmus turned around the left-sided pulmonary veins and then activates the posterolateral to posteroseptal aspect of the CS. MI = mitral isthmus; AP = accessory pathway.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2655075&req=5

Figure 3: Schematic representation of the retrograde atrial activation during orthodromic atrioventricular reentrant tachycardia using a left lateral accessory pathway with concomitant presence of conduction block through the mitral isthmus. A: Explains tracings recorded when a quadripolar catheter was placed in the proximal third of the CS; and B: when a decapolar one was advanced more distally (distal bipole at anterolateral position). Atrial activation wavefront proceeds from the atrial insertion of the accessory pathway along the superior mitral annulus to the His region and then spread to right atrium and proximal to distal CS. Two possibilities might explain why CS bipoles 5-6 to 9-10 are activated from distal (5-6) to proximal (9-10), in panel B: 1-. existence of conduction delay (not complete block) through the mitral isthmus; 2-. activation front through the lateral aspect of the blocked isthmus turned around the left-sided pulmonary veins and then activates the posterolateral to posteroseptal aspect of the CS. MI = mitral isthmus; AP = accessory pathway.
Mentions: The present case shows two interesting aspect: a) intrinsic conduction block (or delay) non-related to prior ablation in the mitral isthmus might exist to some extent in some patients; and b) conduction block in the mitral isthmus in the presence of a laterally located left-sided accessory pathway may alter the atrial activation sequence during either orthodromic atrioventricular reentrant tachycardia or ventricular pacing conducting through the accessory pathway (Figure 3). A detailed mapping along the entire mitral annulus can help us to reveal the exact location of an accessory pathway for patient with previous failed ablation attempt of a left lateral accessory pathway or as in our case, when electrophysiological findings are not totally comprehensible despite an adequate initial evaluation.

Bottom Line: The retrograde atrial activation sequence constitutes an initial important clue to elucidate the tachycardia mechanism during diagnostic electrophysiological testing in patients with supraventricular tachycardia.However, in some cases its correct analysis is challenging.

View Article: PubMed Central - PubMed

Affiliation: Cardiac Arrhythmia and Electrophysiology Unit. Department of Cardiology. Hospital Virgen de la Salud. Toledo. Spain. maapalomares@secardiologia.es

ABSTRACT
The retrograde atrial activation sequence constitutes an initial important clue to elucidate the tachycardia mechanism during diagnostic electrophysiological testing in patients with supraventricular tachycardia. However, in some cases its correct analysis is challenging.

No MeSH data available.


Related in: MedlinePlus