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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\u003ESuccessful ablation of focal atrial tachycardia (AT) requires knowledge of common sites, the ability to identify and localize P waves, use of multipolar mapping, and the knowledge to map and visualize neighboring structures, recognize intracardiac signals of interest, and consider alternative approaches. This article discusses how to maximize ablative success, studies on AT after ablation, high prevalence of AT in patients with congenital heart disease and the diversity of ATs that can develop after open heart surgery and focal AT.\u003C\/p\u003E\n         \u003C\/div\u003E\u003Cul class=\u0022kwd-group\u0022\u003E\u003Cli class=\u0022kwd\u0022\u003EInterventional Techniques \u0026amp; Devices\u003C\/li\u003E\u003Cli class=\u0022kwd\u0022\u003EArrhythmias\u003C\/li\u003E\u003C\/ul\u003E\u003Cul class=\u0022kwd-group clinical-trial\u0022\u003E\u003Cli class=\u0022kwd\u0022\u003EInterventional Techniques \u0026amp; Devices\u003C\/li\u003E\u003Cli class=\u0022kwd\u0022\u003EArrhythmias\u003C\/li\u003E\u003Cli class=\u0022kwd\u0022\u003ECardiology\u003C\/li\u003E\u003C\/ul\u003E\u003Cp id=\u0022p-2\u0022\u003ESuccessful ablation of focal atrial tachycardia (AT) requires knowledge of common sites, the ability to identify and localize P waves, use of multipolar mapping, and the knowledge to map and visualize neighboring structures, recognize intracardiac signals of interest, and consider alternative approaches. Anita Wokhlu, MD, HealthEast Heart Care, Minneapolis-St. Paul, Minnesota, USA, discussed how to maximize ablative success.\u003C\/p\u003E\u003Cp id=\u0022p-3\u0022\u003EDr. Wokhlu reported that the right atrium is the most common anatomic site for AT. Others include the crista terminalis and the tricuspid annulus. Although the majority of left atrial tachycardia (LAT) originate around the ostia of the pulmonary veins, the mitral annulus is an unusual but important site of origin for focal AT, with a propensity to be localized to the superior aspect [Kistler PM et al. \u003Cem\u003EJ Am Coll Cardiol\u003C\/em\u003E 2003]. Atrial appendage sites are associated with a high incidence of incessant tachycardia (84%) and left ventricular (LV) dysfunction (42%) [Medi C et al. \u003Cem\u003EJ Am Coll Cardiol\u003C\/em\u003E 2009].\u003C\/p\u003E\u003Cp id=\u0022p-4\u0022\u003EIn a 2006 report, Kistler et al. [\u003Cem\u003EJ Am Coll Cardiol\u003C\/em\u003E 2006] performed a detailed analysis of the P-wave morphology in AT and developed a detailed algorithm characterizing the likely location of a tachycardia associated with a P wave of unknown origin. Highly specific and sensitive, the P-wave algorithm correctly identified the tachycardia origin in 93% of cases.\u003C\/p\u003E\u003Cp id=\u0022p-5\u0022\u003EWhile multipolar mapping hones the region of interest, risks can include choice of the inappropriate sinus and phrenic injury. Options, according to Dr. Wokhlu, include high-output phrenic pacing (10 to 20 mA; pulse 2 ms); cryomapping and ablation; and insertion of an epicardial balloon to displace the phrenic nerve [Lee JC et al. \u003Cem\u003EHeart Rhythm\u003C\/em\u003E 2009].\u003C\/p\u003E\u003Cp id=\u0022p-6\u0022\u003EDr. Wokhlus noted that atrial appendage tachycardia ablations can be challenging due to complex relational anatomy, variant anatomy (especially left), pectinates interspersed within tissue, low flow, and a perforation risk that may limit endocardial approach. Her presentation also covered mapping and visualizing neighboring structures (eg, Bachman\u0027s bundle, fossa ovalis, coronary sinus ostia), how to recognize intracardiac signals of interest, and alternative ablative approaches (eg epicardial ablation after endocardial fails, lasso-guided ablation).\u003C\/p\u003E\u003Cdiv class=\u0022section\u0022 id=\u0022sec-1\u0022\u003E\n         \u003Ch2 class=\u0022\u0022\u003EMANAGING AND PREVENTING POST AF ABLATION TACHYCARDIA\u003C\/h2\u003E\n         \u003Cp id=\u0022p-7\u0022\u003EDipen Shah, MD, Hopital Cantonal de Geneve, Geneva, Switzerland, presented several studies on AT after ablation. The first report identified discrete isthmuses critical to LATs that may simplify their elimination by catheter ablation [Shah D et al. \u003Cem\u003EJ Cardiovasc Electrophysiol\u003C\/em\u003E 2006].\u003C\/p\u003E\n         \u003Cp id=\u0022p-8\u0022\u003EFifteen patients (all male, 56\u00b18 years) with 15 reentrant LATs following atrial fibrillation (AF) ablation underwent activation and entrainment mapping. Eleven patients (11 LATs) had a single localized site with low amplitude (0.16\u00b10.05 mV), fractionated long duration (131\u00b123 msec) electrograms coinciding with an isoelectric interval of 106\u00b124 msec between flutter waves on all 12 electrocardiogram (ECG) leads [Shah D et al. \u003Cem\u003EJ Cardiovasc Electrophysiol\u003C\/em\u003E 2006]. Three-dimensional mapping and entrainment revealed this site to be a narrow, markedly slow-conducting isthmus adjacent to ablated left (n=8) or right (n=3) pulmonary vein ostia, and critical to nine small diameter (15\u00b13 mm) and two large diameter (49\u00b12 mm) circuits.\u003C\/p\u003E\n         \u003Cp id=\u0022p-9\u0022\u003EOne radiofrequency (RF) application on this isthmus eliminated LAT in all 11 patients. Four patients (4 LATs) with large circuits around the mitral annulus and\/or PV ostia lacked isoelectric ECG intervals and slow-conducting isthmuses and required multiple RF applications across anatomically wide, rapidly conducting isthmuses [Shah D et al. \u003Cem\u003EJ Cardiovasc Electrophysiol\u003C\/em\u003E 2006].\u003C\/p\u003E\n         \u003Cp id=\u0022p-10\u0022\u003EFocally ablatable narrow isthmuses of slow conduction are critical for the majority of reentrant LATs occurring after ablation for AF [Shah D et al. \u003Cem\u003EJ Cardiovasc Electrophysiol\u003C\/em\u003E 2006]. The role and presence of these isthmuses can be anticipated by observing significant isoelectric intervals between the flutter waves on all 12-surface ECG leads. Distinctive electrophysiological characteristics allow their identification and elimination by simple RF ablation.\u003C\/p\u003E\n         \u003Cp id=\u0022p-11\u0022\u003EThe other study dealt with AT after linear lesions, with Prof. Shah covering atrial reentry tachycardia after LA linear lesions [Shah D et al. HRS 2010], pseudo-atypical flutter, perimitral LA flutter with a discrete gap, and small reentry in the mitral isthmus.\u003C\/p\u003E\n         \u003Cp id=\u0022p-12\u0022\u003EProf. Shah reported that nearly a quarter of all patients develop AT\/atrial flutter (AFL) after pulmonary vein isolation plus linear lesions, with LA dilation perhaps disposing to the development of AT\/AFL. Development of AT\/AFL is not associated with conduction block across linear lesions at index ablation and occurs despite complete conduction block in many patients. However, sites of successful ablation are most commonly on or beside linear lesions.\u003C\/p\u003E\n      \u003C\/div\u003E\u003Cdiv class=\u0022section\u0022 id=\u0022sec-2\u0022\u003E\n         \u003Ch2 class=\u0022\u0022\u003EPOSTSURGICAL ATRIAL TACHYCARDIA: ANATOMIC DEFECTS AND SURGICAL APPROACHES\u003C\/h2\u003E\n         \u003Cp id=\u0022p-13\u0022\u003ELi-Wei Lo, MD, and Shih-Ann Chen, MD, National Yang-Min University, Taiwan, China, discussed the high prevalence of AT in patients with congenital heart disease and the diversity of ATs that can develop after open heart surgery (ie, cavotricuspid isthmus [CTI]-dependent AFL, non-CTI-dependent AFL [intra-atrial reentrant tachycardia], and focal AT. They said that AT may develop in as many as 25% of patients who are difficult to manage with antiarrhythmic drug therapy.\u003C\/p\u003E\n         \u003Cp id=\u0022p-14\u0022\u003EMechanisms of postsurgical AT include anatomical characteristics that promote macro-reentry, subtle changes in the electrophysiological substrate of the atrial myocardium (eg, cellular hypertrophy, fibrosis, and co-occurrence of sinus node dysfunction).\u003C\/p\u003E\n         \u003Cp id=\u0022p-15\u0022\u003EThe types of AT and congenital heart disease include isthmus-dependent AFL and intra-atrial reentrant flutter. AF in congenital heart disease is relatively low, seen in end-stage heart disease and\/or left-sided cardiac lesions. Types of surgical incisions are shown in \u003Ca id=\u0022xref-table-wrap-1-1\u0022 class=\u0022xref-table\u0022 href=\u0022#T1\u0022\u003ETable 1\u003C\/a\u003E. The ablation site should be selected according to the location of the incisional scar and the stability of the catheter [Nakao M et al. \u003Cem\u003ECirc J\u003C\/em\u003E 2005].\u003C\/p\u003E\n         \u003Cdiv id=\u0022T1\u0022 class=\u0022table pos-float\u0022\u003E\u003Cdiv class=\u0022table-inline\u0022\u003E\u003Cdiv class=\u0022callout\u0022\u003E\u003Cspan\u003EView this table:\u003C\/span\u003E\u003Cul class=\u0022callout-links\u0022\u003E\u003Cli class=\u00220 first\u0022\u003E\u003Ca href=\u0022\/\u0022 class=\u0022table-expand-inline\u0022 data-table-url=\u0022\/highwire\/markup\/13175\/expansion?postprocessors=highwire_figures%2Chighwire_math%2Chighwire_inline_linked_media%2Chighwire_embed\u0026amp;table-expand-inline=1\u0022 html=\u00221\u0022 fragment=\u0022#\u0022 external=\u00221\u0022 data-icon-position=\u0022\u0022 data-hide-link-title=\u00220\u0022\u003EView inline\u003C\/a\u003E\u003C\/li\u003E\u003Cli class=\u00221\u0022\u003E\u003Ca href=\u0022\/highwire\/markup\/13175\/expansion?width=1000\u0026amp;height=500\u0026amp;iframe=true\u0026amp;postprocessors=highwire_figures%2Chighwire_math%2Chighwire_inline_linked_media\u0022 class=\u0022colorbox colorbox-load table-expand-popup\u0022 rel=\u0022gallery-fragment-tables\u0022 data-icon-position=\u0022\u0022 data-hide-link-title=\u00220\u0022\u003EView popup\u003C\/a\u003E\u003C\/li\u003E\u003Cli class=\u00222 last\u0022\u003E\u003Ca href=\u0022\/highwire\/powerpoint\/13175\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\u003C\/div\u003E\u003Cdiv class=\u0022table-caption\u0022\u003E\u003Cspan class=\u0022table-label\u0022\u003ETable 1.\u003C\/span\u003E \n               \u003Cp id=\u0022p-16\u0022 class=\u0022first-child\u0022\u003ESurgical Incisions in Heart Disease\u003C\/p\u003E\n            \u003Cdiv class=\u0022sb-div caption-clear\u0022\u003E\u003C\/div\u003E\u003C\/div\u003E\u003C\/div\u003E\n         \u003Cp id=\u0022p-18\u0022\u003EOther subjects covered during the presentation were postsurgical mapping techniques of AT, including entrainment, voltage and activation mappings, entrainment versus 3D activation mapping, and case presentations of postsurgical AT.\u003C\/p\u003E\n         \u003Cp id=\u0022p-19\u0022\u003EProfessors Lo and Chen concluded that electrophysiologists need to recognize late arrhythmia after cardiac surgery. In patients with surgically corrected congenital heart disease, AT is most often caused by macroreentrant mechanisms. They recommend a strategy of careful, anatomically-based mapping of the reentrant circuit and validation of acute conduction block.\u003C\/p\u003E\n         \u003Cp id=\u0022p-20\u0022\u003ETogether, these presentations summarize the common sites of focal AT; how to prevent post-AF ablation tachycardias as well as atrial tachycardia and flutter after linear LA lesions; and the importance of anatomic defect and surgical approach in the management of postsurgical AT.\u003C\/p\u003E\n      \u003C\/div\u003E\u003Cul class=\u0022copyright-statement\u0022\u003E\u003Cli class=\u0022fn\u0022 id=\u0022copyright-statement-1\u0022\u003E\u00a9 2013 MD Conference Express\u00ae\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\/13\/3\/28.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_openurl.js?nznzkq\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_tables.js?nznzkq\u0022\u003E\u003C\/script\u003E\n\u003C\/body\u003E\u003C\/html\u003E"}