Characterization of Focal Atrial Tachycardia Using High-Density Mapping

Abstract Background The biatrial trans-septal approach (BTSa) ameliorates mitral valve (MV) exposure in difficult cases when routine left atriotomy doesnt"t allow it. Main steps are an oblique incision on the right atrium (RA), reaching medially the right pulmonary veins (PV), a septal incision from the fossa ovalis, extended up to reach the first incision, then on the left atrium (LA). Purpose We aim to study the arrhythmic burden in this post-surgical context, focusing on atrial tachycardia (AT), to investigate the complexity of several possible circuits. Methods All patients (>18yo) with previous MV surgery via BTSa for MV repair or replacement, who underwent ablation of AT from January 2017 to September 2019, were enrolled. Patients ablated for persistent or paroxysmal AF, or with AF during the index procedure were excluded. Patients with associated surgery on other valves or congenital defects, coronary, surgical or percutaneous rhythm interventions weren’t excluded. Electroanatomical mapping was created using 2 different high-density mapping system. Substrate and activation map and radio-frequency (RF) ablation (25-50W, Ablation Index target 400) were realized. Cartographies were analysed to evaluate AT re-entry circuit, critical isthmus (CI) location and characterization, atrial vulnerability. Procedural outcomes (AT termination, sinus rhythm (SR) restoration, anti-arrhythmic drugs (AAD) withdrawal), and peri-procedural complications were also evaluated. Results We enrolled 49 patients (median age 57 ± 15), finding a maximum of 5 AT per procedure (2 ± 1). A total of 112 AT were mapped: the majority (72%) were persistent AT, 8,2% common atrial flutter. Cycle length was 314 ± 74 msec, with proximal-distal activation of coronary sinus (78%). A multiple re-entry circuit was observed in 70% of index AT. We identified 152 critical isthmus (maximum 5 per procedure). Only 27,9% of our patients had a single CI; CTI was the most frequent one (n = 37), envolved in 33% of all AT, while BTS scars altogether were envolved in 65% AT. A complete AT circuit was mapped in the RA, the LA and both atria in respectively 49%, 11,5% and 39%AT. The distribution of CIs is shown in figure 1. Biatrial and left AT leads to superior procedure, RF and fluoroscopy duration (p <0,05). SR was restored in 93,4%of patients, requiring a DC shock in 4 cases. Immediate AAD withdrawal was achieved after 41%procedures. No pericardial, oesophageal, vascular or phrenic complication occurred. 4 pace-maker implantations were realized because of 3 interatrial, 2 AV block and a sinus node dysfunction. Conclusions AT occurring after a BTSa have a high prevalence of multiple re-entry circuits with multiple critical isthmus. Ablation in this context is feasible and safe but often requires a left atrial access. Mapping of both atria should be considered to identify critical isthmus and tailored ablation strategy. Abstract Figure 1. Critical Isthmus Distribution

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Characterization of a Long Linear Thermolesion in Rabbit Atria by High Density Mapping

Pacing and Clinical Electrophysiology ◽

10.1046/j.1460-9592.2002.00167.x ◽

2002 ◽

Vol 25 (2) ◽

pp. 167-177

Author(s):

OLIVIER PIOT ◽

MAURITS A. ALLESSIE

Keyword(s):

High Density ◽

Density Mapping ◽

Rabbit Atria

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Micro-reentry right atrial tachycardia originating from fossa ovalis: a case report of high-density mapping by PentaRay catheter

European Heart Journal - Case Reports ◽

10.1093/ehjcr/ytz141 ◽

2019 ◽

Vol 3 (3) ◽

Author(s):

Jin-Yi Li ◽

Xiang-Wei Lv ◽

Guo-Qiang Zhong ◽

Hong-Hong Ke

Keyword(s):

Atrial Tachycardia ◽

Mapping Method ◽

High Density ◽

Right Atrial ◽

Ablation Therapy ◽

Density Mapping ◽

Mapping System ◽

Conventional Mapping ◽

Electrophysiological Examination

Abstract Background Micro-reentry tachycardia usually emerges in scar tissues related to post-atrial fibrillation ablation and cardiomyopathy. It is difficult to identify the micro-reentry circuit accurately by conventional mapping method. Case summary A 74-year-old man presented with paroxysmal atrial tachycardia (AT) presenting as palpitations. He was evaluated by an electrophysiological examination using a high-density CARTO mapping system. The mapping results showed the AT with a cycle length of 184 ms was focused on his right atrial fossa ovalis (FO). In this small area, the high-density mapping demonstrated a significant micro-reentrant tachycardia. Radiofrequency ablation at the centre of the micro-reentrant circuit successfully terminated the AT. No recurrences were observed during a 12-month follow-up. Discussion This case demonstrated a micro-reentrant AT originates from the FO without cardiomyopathy or previous ablation with specific loops. This is an unusual location for AT though and can cause difficulty for operators if it terminates or is non-sustained. High-density mapping using a PentaRay catheter can effectively characterize micro-reentrant circuits and determine the real target for ablation therapy.

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Effective and fast characterization of a complex atrial flutter in patient with previous atrial surgery and ablation procedure: The importance of new ultra–high‐density mapping tools

Clinical Case Reports ◽

10.1002/ccr3.3440 ◽

2020 ◽

Vol 8 (12) ◽

pp. 3458-3462

Author(s):

Giuseppe Mascia ◽

Paolo Sartori ◽

Italo Porto

Keyword(s):

Atrial Flutter ◽

High Density ◽

Ablation Procedure ◽

Density Mapping

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Outcome after practical isthmus ablation of scar-related atrial tachycardia guided by high-density mapping

European Heart Journal ◽

10.1093/ehjci/ehaa946.0427 ◽

2020 ◽

Vol 41 (Supplement_2) ◽

Author(s):

C Jungen ◽

R Akbulak ◽

A Kahle ◽

C Eickholt ◽

B Schaeffer ◽

...

Keyword(s):

Catheter Ablation ◽

Atrial Tachycardia ◽

Outcome Data ◽

High Density ◽

Density Mapping ◽

Number Of Patients ◽

Basket Catheter ◽

Acute Success ◽

The Right ◽

Mean Cycle

Abstract Background High-density mapping (HDM) has been found to precisely identify the practical isthmus of scar-related atrial tachycardia (AT) circuits. Since practical isthmuses have been found to be shorter than the usual anatomical isthmuses targeted ablation has been proposed. However, outcome data are sparse. Here we describe HDM-guided catheter ablation by targeting the practical isthmus in patients with scar-related ATs. Methods and results In 250 consecutive patients with scar-related ATs HDM-guided catheter ablation with the support of a 64-electrode mini-basket catheter has been performed. Most patients underwent a prior catheter ablation (98%) while 13% had a prior cardiac valve surgery and 6% an underlying congenital heart disease. A total of 355 ATs occurred in the index procedure, of which 64% had a macro-, 26% a micro-reentry and 10% a focal mechanism. The ATs had a mean cycle length of 304±4.3 ms and in 237 patients (95%) an acute termination into sinus rhythm was achieved. They were mainly located in the left atrium (72%) but also in the right atrium (25%), bi-atrially (5%) or in the CS (3%) (see figure). Targeting the practical isthmus revealed arrhythmia freedom in 53% of patients after a single procedure during a mid-term follow-up (median 489 days, range 95–1407 days). Freedom from any arrhythmia could be achieved in 74% of patients after multiple procedures and in 93% of patients after multiple procedures and optimal clinical therapy, including pharmaceutical or electrical cardioversion. Conclusions HDM-guided catheter ablation of the practical isthmus in patients with scar-related ATs leads to a high acute success rate. Nevertheless, multiple procedures are necessary in a relevant number of patients resulting in a low recurrence rate. Funding Acknowledgement Type of funding source: None

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The experience of radiofrequency ablation of atrial tachycardia focus with the use of high-density myocardial mapping

Kazan medical journal ◽

10.17816/kmj2019-340 ◽

2019 ◽

Vol 100 (2) ◽

pp. 340-344

Author(s):

A S Omelyanenko ◽

T I Mavlyudov ◽

O V Sapelnikov ◽

D I Cherkashin ◽

I M Islamova ◽

...

Keyword(s):

Heart Rate ◽

Radiofrequency Ablation ◽

High Resolution ◽

Sinus Rhythm ◽

Navigation System ◽

Atrial Tachycardia ◽

High Density ◽

Radiation Load ◽

Focal Atrial Tachycardia ◽

Electrophysiological Examination

The article presents a case of successful treatment of focal atrial tachycardia by radiofrequency ablation using high-density myocardial mapping. The aim of the work was to evaluate the possibilities of high-resolution myocardial mapping by EnsitePrecision® navigation system in the treatment of complex arrhythmias. The analysis of clinical data and results of electrophysiological examination of a 29-year-old patient with continuous recurrent focal atrial tachycardia was carried out. The patient was admitted with complaints of heart rate disorders and frequent short attacks of palpitations. According to electrocardiography, frequent short paroxysms of focal atrial tachycardia were revealed. The patient was taken for electrophysiological examination and radiofrequency ablation of the focus of atrial tachycardia. The focus of atrial tachycardia was located in the anterior septal part of the left atrium, which is a rare localization. After radiofrequency ablation tachycardia was terminated, no complications and recurrences were registered. The patient was discharged with the sinus rhythm. Navigation system EnsitePrecision® enables conducting high-density myocardial mapping, which helps to accurately determine the localization of the source of tachycardia. The radiation load on the patient and ablation time are reduced, which reduces the frequency of complications from the procedure.

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