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type=\u0022text\/css\u0022 rel=\u0022stylesheet\u0022 href=\u0022\/\/d282kpwvnogo5m.cloudfront.net\/sites\/default\/files\/advagg_css\/css__ce2QY63WIanKyr8eSq7eavr1XQRRmFD6ZSmwpyJi8lM__zXwFqpqmxrZOXXcd_TpBQpjuELbmIP9wBR5UuTDWAO4__YJWWMMdfCJuAFm5cUEp88OsodhO3ZA-2lzRfoBsSlk4.css\u0022 media=\u0022all\u0022 \/\u003E\n\u003Clink rel=\u0027stylesheet\u0027 type=\u0027text\/css\u0027 href=\u0027\/sites\/all\/modules\/contrib\/panels\/plugins\/layouts\/onecol\/onecol.css\u0027 \/\u003E\u003C\/head\u003E\u003Cbody\u003E\u003Cdiv class=\u0022panels-ajax-tab-panel panels-ajax-tab-panel-sageoa-tab-art\u0022\u003E\u003Cdiv class=\u0022panel-display panel-1col clearfix\u0022 \u003E\n  \u003Cdiv class=\u0022panel-panel panel-col\u0022\u003E\n    \u003Cdiv\u003E\u003Cdiv class=\u0022panel-pane pane-highwire-markup\u0022 \u003E\n  \n      \n  \n  \u003Cdiv class=\u0022pane-content\u0022\u003E\n    \u003Cdiv class=\u0022highwire-markup\u0022\u003E\u003Cdiv xmlns=\u0022http:\/\/www.w3.org\/1999\/xhtml\u0022 id=\u0022content-block-markup\u0022 xmlns:xhtml=\u0022http:\/\/www.w3.org\/1999\/xhtml\u0022\u003E\u003Cdiv class=\u0022article fulltext-view \u0022\u003E\u003Cspan class=\u0022highwire-journal-article-marker-start\u0022\u003E\u003C\/span\u003E\u003Cdiv class=\u0022section abstract\u0022 id=\u0022abstract-1\u0022\u003E\u003Ch2\u003ESummary\u003C\/h2\u003E\n            \u003Cp id=\u0022p-1\u0022\u003EThis article discusses practical strategies for radiofrequency (RF) catheter ablation of atrioventricular nodal reentry tachycardia (AVNRT), including slow and fast pathway ablation. Furthermore, cryoablation versus RF for AVNRT is also discussed.\u003C\/p\u003E\n         \u003C\/div\u003E\u003Cul class=\u0022kwd-group\u0022\u003E\u003Cli class=\u0022kwd\u0022\u003EArrhythmias\u003C\/li\u003E\u003Cli class=\u0022kwd\u0022\u003EInterventional Radiology\u003C\/li\u003E\u003Cli class=\u0022kwd\u0022\u003EInterventional Techniques \u0026amp; Devices\u003C\/li\u003E\u003C\/ul\u003E\u003Cp id=\u0022p-2\u0022\u003EClaus Schmitt, MD, Medizinische Klinik IV, St\u00e4dtisches Klinikum Karlsruhe, Karlsruhe, Germany, discussed practical strategies for radiofrequency (RF) catheter ablation of atrioventricular nodal reentry tachycardia (AVNRT), including slow and fast pathway ablation. Prof. Schmitt prefers a 3-catheter setting using the slow pathway. Using this technique, many interventionists start from a left anterior oblique (LAO) projection; in this position, a His bundle potential can be recorded simultaneously with the catheter in the His position.\u003C\/p\u003E\u003Cp id=\u0022p-3\u0022\u003ETo target the slow pathway, interventionists may use an anatomic approach, an electrogram-guided approach, or an integrated approach. Prof. Schmitt prefers the latter. A typical setup is a His bundle recording with a coronary sinus catheter and an ablation catheter. Isoproterenol is used if the patient can not be induced and to determine success of the ablation. Use of sedation may increase vagal tone and make it difficult to induce the arrhythmia. In noninducible patients, if there are no accessory pathways after tachycardia and there is documented supraventricular tachycardia (SVT) that is compatible with AVNRT, Prof. Schmitt recommends continuing with the ablation.\u003C\/p\u003E\u003Cp id=\u0022p-4\u0022\u003ESlow pathway ablation typically is performed in sinus rhythm, starting from LAO or right anterior oblique projections using 20 to 30 watts for up to 60 seconds to reach \u0026gt;50\u00b0C. If there are many junctional beats (\u003Ca id=\u0022xref-fig-1-1\u0022 class=\u0022xref-fig\u0022 href=\u0022#F1\u0022\u003EFigure 1\u003C\/a\u003E) at the start of RF application, Prof. Schmitt paces the atrium to determine if the fast pathway is intact. It is best to stop at 60-second intervals if the fast pathway is compromised. Accelerated junctional rhythm occurs in almost 100% of effective sites but also in up to 65% of ineffective sites.\u003C\/p\u003E\u003Cdiv id=\u0022F1\u0022 class=\u0022fig pos-float  odd\u0022\u003E\u003Cdiv class=\u0022highwire-figure\u0022\u003E\u003Cdiv class=\u0022fig-inline-img-wrapper\u0022\u003E\u003Cdiv class=\u0022fig-inline-img\u0022\u003E\u003Ca href=\u0022http:\/\/d282kpwvnogo5m.cloudfront.net\/content\/spmdc\/12\/6\/15\/F1.large.jpg?width=800\u0026amp;height=600\u0026amp;carousel=1\u0022 title=\u0022Start of Ablation: Junctional Beats.\u0022 class=\u0022fragment-images colorbox-load\u0022 rel=\u0022gallery-fragment-images-1333760940\u0022 data-figure-caption=\u0022Start of Ablation: Junctional Beats.\u0022 data-icon-position=\u0022\u0022 data-hide-link-title=\u00220\u0022\u003E\u003Cimg class=\u0022fragment-image\u0022 alt=\u0022Figure 1.\u0022 src=\u0022http:\/\/d282kpwvnogo5m.cloudfront.net\/content\/spmdc\/12\/6\/15\/F1.medium.gif\u0022\/\u003E\u003C\/a\u003E\u003C\/div\u003E\u003C\/div\u003E\u003Cul class=\u0022highwire-figure-links inline\u0022\u003E\u003Cli class=\u00220 first\u0022\u003E\u003Ca href=\u0022http:\/\/d282kpwvnogo5m.cloudfront.net\/content\/spmdc\/12\/6\/15\/F1.large.jpg?download=true\u0022 class=\u0022highwire-figure-link highwire-figure-link-download\u0022 title=\u0022Download Figure 1.\u0022 data-icon-position=\u0022\u0022 data-hide-link-title=\u00220\u0022\u003EDownload figure\u003C\/a\u003E\u003C\/li\u003E\u003Cli class=\u00221\u0022\u003E\u003Ca href=\u0022http:\/\/d282kpwvnogo5m.cloudfront.net\/content\/spmdc\/12\/6\/15\/F1.large.jpg\u0022 class=\u0022highwire-figure-link highwire-figure-link-newtab\u0022 target=\u0022_blank\u0022 data-icon-position=\u0022\u0022 data-hide-link-title=\u00220\u0022\u003EOpen in new tab\u003C\/a\u003E\u003C\/li\u003E\u003Cli class=\u00222 last\u0022\u003E\u003Ca href=\u0022\/highwire\/powerpoint\/14315\u0022 class=\u0022highwire-figure-link highwire-figure-link-ppt\u0022 data-icon-position=\u0022\u0022 data-hide-link-title=\u00220\u0022\u003EDownload powerpoint\u003C\/a\u003E\u003C\/li\u003E\u003C\/ul\u003E\u003C\/div\u003E\u003Cdiv class=\u0022fig-caption attrib\u0022\u003E\u003Cspan class=\u0022fig-label\u0022\u003EFigure 1.\u003C\/span\u003E \n            \u003Cp id=\u0022p-5\u0022 class=\u0022first-child\u0022\u003EStart of Ablation: Junctional Beats.\u003C\/p\u003E\n         \u003Cq class=\u0022attrib\u0022 id=\u0022attrib-1\u0022\u003EReproduced with permission from C. Schmitt, MD.\u003C\/q\u003E\u003Cdiv class=\u0022sb-div caption-clear\u0022\u003E\u003C\/div\u003E\u003C\/div\u003E\u003C\/div\u003E\u003Cp id=\u0022p-6\u0022\u003EA successful ablation can be proved by noninducibility with or without isoproterenol. In a complete ablation of the slow pathway, there is no jump or echo beat. If the slow pathway is modified, it is acceptable to have a jump and up to 1 atrial echo beat. During RF ablation in atypical AVNRT, the slow pathway is mapped during tachycardia.\u003C\/p\u003E\u003Cp id=\u0022p-7\u0022\u003ESome studies have reported that fast pathway ablation is an acceptable approach in patients with AVNRT and a prolonged PR interval [Reithmann C et al. \u003Cem\u003EJ Cardiovasc Electrophysiol\u003C\/em\u003E 2006]. There might be more than 1 slow pathway; however, and if care is taken, slow pathway ablation can be safe.\u003C\/p\u003E\u003Cp id=\u0022p-8\u0022\u003EProf Schmitt\u0027s laboratory reported a 98.8% acute success rate with a recurrence rate of 5.2% [Estner HL et al. \u003Cem\u003EPacing Clin Electrophysiol\u003C\/em\u003E 2005]. Complications, such as late AV block with RF lesion extension, have been reported in up to 0.4% of patients. The Cryoablation versus Radiofrequency Energy for the Ablation of Atrioventricular Nodal Reentrant Tachycardia study [CYRANO] [Deisenhofer I et al. \u003Cem\u003ECirculation\u003C\/em\u003E 2010] reported that AVNRT recurrence is more frequent with cryoablation versus RF ablation (9.4% vs 4.4%; p=0.029).\u003C\/p\u003E\u003Cdiv class=\u0022section\u0022 id=\u0022sec-1\u0022\u003E\n         \u003Ch2 class=\u0022\u0022\u003ECryoablation of AVNRT\u003C\/h2\u003E\n         \u003Cp id=\u0022p-9\u0022\u003ELuc Jordaens, MD, PhD, Thoraxcentre, Rotterdam, The Netherlands, discussed cryoablation versus RF for AVNRT. In RF ablation, the interventionist must look for accelerated junctional rhythm during the procedure. Testing is repeated after each site or after occurrence of junctional rhythm. Fluoroscopy is used throughout the application. Junctional rhythm never occurs with cryoablation. Cryoablation is started with ice mapping at \u221230\u00b0C. If disappearance of the atrium-His (AH) jump is not feasible, the operator attempts to determine within the minute of mapping if a noninducible AVNRT occurs. If noninducible AVNRT is present without damage to the fast pathway, the temperature can be decreased to \u221280\u00b0C for complete ablation. Progressive AH lengthening can be checked with atrial extrastimuli; if AH jump is absent, then the ablation can continue. Cryoablation can be used to create a reversible lesion or a complete heart block.\u003C\/p\u003E\n         \u003Cp id=\u0022p-10\u0022\u003EAn analysis of several studies that compared long-term outcomes of cryoablation versus RF showed acute success rates of 93% versus 96% and recurrence rates of 10% versus 4.2%, respectively [Schwagten B et al. \u003Cem\u003EEuropace\u003C\/em\u003E 2010]. Median procedure times were similar, but fluoroscopy times were lower with cryoablation.\u003C\/p\u003E\n         \u003Cp id=\u0022p-11\u0022\u003EAVNRT cryoablation is safe in the long term. Mapping capabilities are unique, and it can be used after prior cryoablation or RF ablation. Inducibility is not required if dual conduction is present. Absence of echo beats predicts long-term success. Prof. Jordaens concluded that there is no real need for RF ablation.\u003C\/p\u003E\n      \u003C\/div\u003E\u003Cul class=\u0022copyright-statement\u0022\u003E\u003Cli class=\u0022fn\u0022 id=\u0022copyright-statement-1\u0022\u003E\u00a9 2012 MD Conference Express\u003C\/li\u003E\u003C\/ul\u003E\u003Cspan class=\u0022highwire-journal-article-marker-end\u0022\u003E\u003C\/span\u003E\u003C\/div\u003E\u003Cspan id=\u0022related-urls\u0022\u003E\u003C\/span\u003E\u003C\/div\u003E\u003Ca href=\u0022http:\/\/mdc.sagepub.com\/content\/12\/6\/15.abstract\u0022 class=\u0022hw-link hw-link-article-abstract\u0022 data-icon-position=\u0022\u0022 data-hide-link-title=\u00220\u0022\u003EView Summary\u003C\/a\u003E\u003C\/div\u003E  \u003C\/div\u003E\n\n  \n  \u003C\/div\u003E\n\u003C\/div\u003E\n  \u003C\/div\u003E\n\u003C\/div\u003E\n\u003C\/div\u003E\u003Cscript type=\u0022text\/javascript\u0022 src=\u0022http:\/\/mdc.sagepub.com\/sites\/all\/modules\/highwire\/highwire\/plugins\/highwire_markup_process\/js\/highwire_figures.js?nzndtd\u0022\u003E\u003C\/script\u003E\n\u003Cscript type=\u0022text\/javascript\u0022 src=\u0022http:\/\/mdc.sagepub.com\/sites\/all\/modules\/highwire\/highwire\/plugins\/highwire_markup_process\/js\/highwire_openurl.js?nzndtd\u0022\u003E\u003C\/script\u003E\n\u003C\/body\u003E\u003C\/html\u003E"}