SPC365

Biatrial flutters uncommon circuits requiring tailored ablation approach

Session: Sessão de Posters 41 - Taquiarritmias supraventriculares
Speaker: João Mendes Cravo

Congress: CPC 2024
Topic: C. Arrhythmias and Device Therapy
Theme: 04. Arrhythmias, General
Subtheme: 04.6 Arrhythmias, General – Clinical
Session Type: Cartazes
FP Number: ---
Authors: João Mendes Cravo; Ana Beatriz Garcia; Ana Margarida Martins; Catarina Simões de Oliveira; Ana Abrantes; Joana Brito; Nelson Cunha; Afonso Nunes-Ferreira; Gustavo Silva; Nuno Cortez Dias; F.J. Pinto; João de Sousa

<p><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif"><strong>Introduction</strong>: Atrial flutters are macroreentrant tachycardias that typically involve several walls&nbsp;</span></span><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif">of a certain atrium, being the other atrium passively activated. Biatrial flutters (BAF) are&nbsp;</span></span><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif">peculiar macro-reentries associated with anterior/septal scars, involving both atrial and using&nbsp;</span></span><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif">the interatrial connections.</span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif"><strong>Purpose: </strong>To characterize the mechanism of BAF in a cohort of patients (pts) submitted to&nbsp;</span></span><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif">mapping and ablation.</span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif"><strong>Methods</strong>: Retrospective single-center study of pts with atypical atrial flutter submitted to&nbsp;</span></span><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif">ablation from 2015 to 2022. High resolution electro anatomical voltage and activation mapping&nbsp;</span></span><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif">were collected using Carto, Ensite or Rhythmia. Whenever the arrhythmia circuit was not fully&nbsp;</span></span><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif">displayed in a certain atrium, the other atrium was mapped to fully characterize the&nbsp;</span></span><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif">reentrant circuit and establish the critical isthmus. Biatrial circuits were classified into 4 types: type 1, involving the mitral annulus and the tricuspid annulus, escaping the septal wall in both atria; type 2 using most of the mitral annulus and the right atrium (RA) septum; type 3, using both the left atrium (LA) and RA septum; and type 4, using most of the tricuspid annulus and the LA septum. Acute and long-term success was evaluated.</span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif"><strong>Results</strong>: From a total of 107 pts submitted to atypical flutter ablation, 5 pts presented BAF (3&nbsp;</span></span><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif">male, median age: 55-yo), 4 of them previously submitted to cardiac surgery (CABG in 1, mitral&nbsp;</span></span><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif">valvuloplasty in 1, mitral+tricuspid valvuloplasty in 1 and surgical correction of aortic coarctation and ostium primum atrium septal defect in 1) and 1 had been previously submitted to pulmonary vein isolation (PVI), empirical roof line and cavo tricuspid isthmus (CTI) ablation. A proximal-to-distal coronary sinus activation and extensive low-voltage areas at the septum were recognized in all these pts. The BAF mechanism was single loop in all of them, with a type 2 circuit in 2 pts, and types 1, 3 and 4 in one patient each. BAF types 1 and 4 were terminated with CTI ablaon. BAF types 2 and 3 were terminated with linear ablations from the mitral annulus to the right superior PV, complemented with focal applications at Bachmann bundle insertion sites in the pts with type 2 BAF. Acute success was achieved in all pts. During a mean time of follow-up of 344&plusmn;91 days, 1 pt had AFl recurrence.</span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif"><strong>Conclusion</strong>: BAF is a rare and complex arrhythmia, which is possible to ablate successfully by applying high-density mapping tools, a comprehensive analysis of the substrate/activation maps and a mechanism-tailored ablation strategy.</span></span></p>