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33rd International Congress on Electrocardiology

International Society of Electrocardiology

Catheter Ablation of AVNRT in Children

Meeting Abstract

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  • corresponding author presenting/speaker M. Emmel - Kinderkardiologie Universitätsklinikum Köln, Köln, Germany
  • author N. Sreeram - Kinderkardiologie Universitätsklinikum Köln, Köln, Germany
  • author K. Brockmeier - Kinderkardiologie Universitätsklinikum Köln, Köln, Germany

33rd International Congress on Electrocardiology. Cologne, 28.06.-01.07.2006. Düsseldorf, Köln: German Medical Science; 2007. Doc06ice009

The electronic version of this article is the complete one and can be found online at:

Published: February 8, 2007

© 2007 Emmel et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.



AV-nodal Reentry Tachycardia is a narrow QRS-complex with a short RP-interval that starts and stops suddenly (switch-on switch-off).

A reentry within the AV-node is the underlying pathophysiology. For this a dissociation into a fast and a slow pathway (or a fast and a slow input to the AV-node) is required. Dual AV-node physiology (DAVNP) is tested by atrial extrastimulation techniqes. A discontinuous AH.curve with >50 ms “jump” in AH-time following an AA decrement of 10 ms indicates DAVNP.

In children there are some differences to the observations that have been made in adults. First, DAVNP using the above definition is only found in 40-60% of children with AVNRT. Second, DAVNP can be found in 25% of the healthy population. Redefining the cut-off level for the AV-jump does not allow to discriminate AVNRT patients from healthy children. The type of conduction curve (continous vs. discontinous) is also not specific for AVNRT.

“Sustained slow pathway conduction” which is defined by a PR ≥RR during the fastest atrial pacing with 1:1 conduction is more sensitive and more specific in children as well as in adults. Thus it allows to identify AVNRT patients and is also helpful for end point determination following ablation therapy.

Also the maximal AH-interval during atrial extrastimulation is significantly longer in patients with AVNRT, but there is a significant overlap with the healthy population. Whilst the max. AH-interval does not allow to identify AVNRT patients, it may be useful as an individual end point marker, because it decreases in most patients after successful slow-pathway ablation.

Radiofrequency (RF) current is the method of choice for slow-pathway ablation, providing high success with low complication rates. But RF creates an irreversible lesion close to the AV-node/bundle of His, with a procedure related risk for complete heart block. Thus, there is a theoretical advantage of cryomapping and –ablation, when a reversible lesion (mapping) is turned into an irreversible lesion (ablation) if the desired effect is observed with no unwanted effects. The results of cryoablation are at present inferior to the results of ablation with RF, with higher recurrence rates, but will improve with more experience.