Atrial flutter: more than just one of a kind Bun, Sok-Sithikun; Latcu, Decebal Gabriel; Marchlinski, Francis ...
European heart journal,
09/2015, Volume:
36, Issue:
35
Journal Article
Peer reviewed
Open access
Since its first description about one century ago, our understanding of atrial flutter (AFL) circuits has considerably evolved. One AFL circuit can have variable electrocardiographic (ECG) ...manifestations depending on the presence of pre-existing atrial lesions, or impaired atrial substrate. Conversely, different (right sided or even left sided) atrial circuits including different mechanisms (macroreentrant, microreentrant, or focal) can present with a very similar surface ECG manifestation. The development of efficient high-resolution electroanatomical mapping systems has improved our knowledge about AFL mechanisms, as well as facilitated their curative treatment with radiofrequency catheter ablation. This article will review ECG features for typical and atypical flutters, and emphasize the limitations for circuit location from the surface ECG.
Introduction
The impact of atrial arrhythmias on coronavirus disease 2019 (COVID‐19)‐associated outcomes are unclear. We sought to identify prevalence, risk factors and outcomes associated with ...atrial arrhythmias among patients hospitalized with COVID‐19.
Methods
An observational cohort study of 1053 patients with severe acute respiratory syndrome coronavirus 2 infection admitted to a quaternary care hospital and a community hospital was conducted. Data from electrocardiographic and telemetry were collected to identify atrial fibrillation (AF) or atrial flutter/tachycardia (AFL). The association between atrial arrhythmias and 30‐day mortality was assessed with multivariable analysis.
Results
Mean age of patients was 62 ± 17 years and 62% were men. Atrial arrhythmias were identified in 166 (15.8%) patients, with AF in 154 (14.6%) patients and AFL in 40 (3.8%) patients. Newly detected atrial arrhythmias occurred in 101 (9.6%) patients. Age, male sex, prior AF, renal disease, and hypoxia on presentation were independently associated with AF/AFL occurrence. Compared with patients without AF/AFL, patients with AF/AFL had significantly higher levels of troponin, B‐type natriuretic peptide, C‐reactive protein, ferritin and
d‐dimer. Mortality was significantly higher among patients with AF/AFL (39.2%) compared to patients without (13.4%; p < .001). After adjustment for age and co‐morbidities, AF/AFL (adjusted odds ratio OR: 1.93; p = .007) and newly detected AF/AFL (adjusted OR: 2.87; p < .001) were independently associated with 30‐day mortality.
Conclusion
Atrial arrhythmias are common among patients hospitalized with COVID‐19. The presence of AF/AFL tracked with markers of inflammation and cardiac injury. Atrial arrhythmias were independently associated with increased mortality.
Smartwatch and fitness band wearable consumer electronics can passively measure pulse rate from the wrist using photoplethysmography (PPG). Identification of pulse irregularity or variability from ...these data has the potential to identify atrial fibrillation or atrial flutter (AF, collectively). The rapidly expanding consumer base of these devices allows for detection of undiagnosed AF at scale.
The Apple Heart Study is a prospective, single arm pragmatic study that has enrolled 419,093 participants (NCT03335800). The primary objective is to measure the proportion of participants with an irregular pulse detected by the Apple Watch (Apple Inc, Cupertino, CA) with AF on subsequent ambulatory ECG patch monitoring. The secondary objectives are to: 1) characterize the concordance of pulse irregularity notification episodes from the Apple Watch with simultaneously recorded ambulatory ECGs; 2) estimate the rate of initial contact with a health care provider within 3 months after notification of pulse irregularity. The study is conducted virtually, with screening, consent and data collection performed electronically from within an accompanying smartphone app. Study visits are performed by telehealth study physicians via video chat through the app, and ambulatory ECG patches are mailed to the participants.
The results of this trial will provide initial evidence for the ability of a smartwatch algorithm to identify pulse irregularity and variability which may reflect previously unknown AF. The Apple Heart Study will help provide a foundation for how wearable technology can inform the clinical approach to AF identification and screening.
SparkleMap-based left atrial flutter mapping and ablation Cortez-Dias, Nuno; Lima da Silva, Gustavo; Nunes Ferreira, Afonso ...
Revista portuguesa de cardiologia,
April 2023, 2023-04-00, 2023-04-01, Volume:
42, Issue:
4
Journal Article
Peer reviewed
Open access
Ablation of atypical left atrial flutters (LAF) is very challenging due to the complexity of the underlying atrial substrate and diverse arrhythmia mechanisms. The interpretation of the arrhythmia ...mechanism is usually difficult, even using advanced three-dimensional (3D) mapping systems. SparkleMap is a novel mapping algorithm that displays each electrogram as a green dot that lights up at the point corresponding to the local activation time, superimposed either on the substrate or the local activation time 3D-maps. It is not affected by the setting of the “window of interest” and there is no need for user post-processing.
We present the case of patient with a persistent atypical LAF in whom we tested the concept of complex arrhythmia interpretation exclusively based on the analysis of the substrate and evaluation of SparkleMap-derived wavefront propagation. We describe the workflow for map collection and the systematic approach for arrhythmia interpretation that resulted in the identification of a dual loop perimitral mechanism with a common slow conducting isthmus inside a scar at the septum/anterior atrial wall. This new method of analysis enabled the use of a specifically targeted and precise approach for ablation, with restoration of sinus rhythm within five seconds of radiofrequency application. After 18 months of follow-up, the patient remains free from recurrences, without anti-arrhythmic medication. This case report exemplifies how helpful new mapping algorithms can be in the interpretation of the arrhythmia mechanism in patients with complex LAF. It also suggests an innovative workflow to integrate the SparkleMap into the mapping approach.
A ablação dos flutters atípicos da aurícula esquerda constitui frequentemente um desafio devido à complexidade do substrato auricular subjacente e à diversidade dos mecanismos arrítmicos implicados. A interpretação do mecanismo da arritmia é usualmente difícil, mesmo utilizando sistemas avançados de mapeamento eletroanatómico tridimensional. O SparkleMap é um novo algoritmo de mapeamento que representa cada eletrograma como um ponto verde que acende no momento correspondente ao momento da ativação local. Pode ser sobreposto ao mapa tridimensional de substrato ou de ativação, não é influenciado pela escolha da janela de interesse do mapa e não requer pós-processamento manual.
Apresentamos o caso de um doente com flutter atípico persistente em quem testámos a interpretação do mecanismo de arritmias complexas com base exclusivamente na análise do substrato e na avaliação da propagação das ondas eléctricas por SparkleMap. Descrevemos o protocolo para a colheita do mapa e para a análise sistemática do mecanismo da arritmia, que resultou na identificação de um mecanismo de dupla-reentrada, com um dos circuitos em rotação perimitral e localizando-se o istmo comum de condução lenta na parede anterior/septo, num canal de miocárdio viável intracicatricial. Este método de análise inovador resultou numa estratégia de ablação dirigida e precisa, que conduziu à reposição de ritmo sinusal após apenas 5 segundos de ablação. Com um seguimento de 18 meses, o doente mantém-se livre de recorrências, sem terapêutica antiarrítmica.
Este caso clínico exemplifica como os novos algoritmos de mapeamento podem ser úteis na interpretação dos mecanismos arrítmicos em doentes com arritmias auriculares complexas e propõe um protocolo inovador para a incorporação do SparkleMap na estratégia de mapeamento.
Purpose
We aimed to elucidate the right atrial posterior wall (RAPW) and interatrial septum (IAS) conduction pattern during reverse typical atrial flutter (clockwise AFL: CW-AFL).
Methods
This study ...included 30 patients who underwent catheter ablation of CW-AFL (
n
= 11) and counter-clockwise AFL (CCW-AFL;
n
= 19) using an ultra-high resolution mapping system. RAPW transverse conduction block was evaluated by the conduction pattern on propagation maps and double potentials separated by an isoelectric line. The degree of blockade was evaluated by the %blockade, which was calculated by the length of the blocked area divided by the RAPW length. IAS activation patterns were also investigated dependent on the propagation map.
Results
The average %blockade of the RAPW was significantly smaller in patients with CW-AFL than those with CCW-AFL (25 3–74% vs. 67 57–75%,
p
< 0.05). CW-AFL patients exhibited 3 different RAPW conduction patterns: (1) a complete blockade pattern (3 patients), (2) moderate (> 25% blockade) blockade pattern (2 patients), and (3) little (< 25% blockade) blockade pattern (6 patients). In contrast, the little blockade pattern was not observed in CCW-AFL patients. Of 11 CW-AFL patients, 4, including all patients with an RAPW complete blockade pattern, had an IAS activation from the wavefront from the anterior tricuspid annulus (TA), and 6 had an IAS activation from the wavefronts from both the anterior TA and RAPW. One patient had IAS activation dominantly from the wavefront from the RAPW.
Conclusions
RAPW transverse conduction blockade during CW-AFL was less frequent than during CCW-AFL, which possibly caused various IAS activation patterns.
Peak frequency mapping of atypical atrial flutter Karatela, Maham F.; Dowell, Robert S.; Friedman, Daniel J. ...
Journal of cardiovascular electrophysiology,
20/May , Volume:
35, Issue:
5
Journal Article
Peer reviewed
Introduction
Peak frequency (PF) mapping is a novel method that may identify critical portions of myocardial substrate supporting reentry. The aim of this study was to describe and evaluate ...PF mapping combined with omnipolar voltage mapping in the identification of critical isthmuses of left atrial (LA) atypical flutters.
Methods and Results
LA omnipolar voltage and PF maps were generated in flutter using the Advisor HD‐Grid catheter (Abbott) and EnSite Precision Mapping System (Abbott) in 12 patients. Normal voltage was defined as ≥0.5 mV, low‐voltage as 0.1−0.5 mV, and scar as <0.1 mV. PF distributions were compared with ANOVA and post hoc Tukey analyses. The 1 cm radius from arrhythmia termination was compared to global myocardium with unpaired t‐testing. The mean age was 65.8 ± 9.7 years and 50% of patients were female. Overall, 34 312 points were analyzed. Atypical flutters most frequently involved the mitral isthmus (58%) or anterior wall (25%). Mean PF varied significantly by myocardial voltage: normal (335.5 ± 115.0 Hz), low (274.6 ± 144.0 Hz), and scar (71.6 ± 140.5 Hz) (p < .0001 for all pairwise comparisons). All termination sites resided in low‐voltage regions containing intermediate or high PF. Overall, mean voltage in the 1 cm radius from termination was significantly lower than the remaining myocardium (0.58 vs. 0.95 mV, p < .0001) and PF was significantly higher (326.4 vs. 245.1 Hz, p < .0001).
Conclusion
Low‐voltage, high‐PF areas may be critical targets during catheter ablation of atypical atrial flutter.
Atrial flutter (AFL) and atrial fibrillation (AF) are associated with AF-promoting atrial remodeling, but no experimental studies have addressed remodeling with sustained AFL.
This study aimed to ...define the atrial remodeling caused by sustained atrial flutter (AFL) and/or atrial fibrillation (AF).
Intercaval radiofrequency lesions created a substrate for sustained isthmus-dependent AFL, confirmed by endocavity mapping. Four groups (6 dogs per group) were followed for 3 weeks: sustained AFL; sustained AF (600 beats/min atrial tachypacing); AF superimposed on an AFL substrate (AF+AFLs); sinus rhythm (SR) with an AFL substrate (SR+AFLs; control group). All dogs had atrioventricular-node ablation and ventricular pacemakers at 80 beats/min to control ventricular rate.
Monitoring confirmed spontaneous AFL maintenance >99% of the time in dogs with AFL. At terminal open-chest study, left-atrial (LA) effective refractory period was reduced similarly with AFL, AF+AFLs and AF, while AF vulnerability to extrastimuli increased in parallel. Induced AF duration increased significantly in AF+AFLs and AF, but not AFL. Dogs with AF+AFLs had shorter cycle lengths and substantial irregularity versus dogs with AFL. LA volume increased in AF+AFLs and AF, but not dogs with AFL, versus SR+AFLs. Optical mapping showed significant conduction slowing in AF+AFLs and AF but not AFL, paralleling atrial fibrosis and collagen-gene upregulation. Left-ventricular function did not change in any group. Transcriptomic analysis revealed substantial dysregulation of inflammatory and extracellular matrix-signaling pathways with AF and AF+ALs but not AFL.
Sustained AFL causes atrial repolarization changes like those in AF but, unlike AF or AF+AFLs, does not induce structural remodeling. These results provide novel insights into AFL-induced remodeling and suggest that early intervention may be important to prevent irreversible fibrosis when AF intervenes in a patient with AFL.
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Purpose
The purpose of this study was to evaluate ultra high density-activation sequence mapping (UHD-ASM) for ablating atypical atrial flutters.
Methods
For 23 patients with 31 atypical atrial ...flutters (AAF), we created UHD-ASM.
Results
Demographics age = 65.3 ± 8.5 years, male = 78%, left atrial size = 4.66 ± 0.64 cm, redo ablation 20/23(87%). AAF were left atrial in 30 (97%). For each AAF, 1273 ± 697 points were used for UHD-ASM. Time to create and interpret the UHD-ASM was 20 ± 11 min. For every AAF, the entire circuit was identified. Thirty (97%) were macroreentry. AAF cycle length was 267 ± 49 ms, and the circuit length was 138 ± 38 mm (range 35–187). Macroreentry atrial flutters took varied pathways, but each had an area of slow conduction (ASC) averaging 16 ± 6 mm (range 6–29) in length. Entrainment was not utilized. We targeted the ASC and ablation terminated AAF directly in 19/31 (61.3%) and altered AAF activation in 7/31 (22.6%), all of which terminated directly with additional mapping/ablation. AAF degenerated to atrial fibrillation in 2/31 (6.5%) with RF and could not be reinduced after ASC ablation. Median time from initial ablation to AAF termination was 64 s. Thus, 28/31 (90.3%) terminated with RF energy and/or could not be reinduced after ASC ablation. At 1 year of follow-up, 77% were free of atrial tachycardia or atrial flutter and 61% were free of all atrial arrhythmias.
Conclusions
Using rapidly acquired UHD-ASM, the entire AAF circuit as well as the target ASC could be identified. Most AAF were left atrial macroreentry. Ablation of the ASC or microreentry focuses directly terminated or eliminated AAF in 90.3% without the need for entrainment mapping.
Left atrial flutter (LAFL) occurs in patients after atrial fibrillation ablation. Identification of optimal ablation targets to terminate LAFL remains challenging.
The purpose of this study was to ...use patient-specific models to simulate LAFL and predict optimal ablation targets using a novel approach based on flow network theory.
Late gadolinium-enhanced cardiac magnetic resonance scans from 10 patients with LAFL were used to construct atrial models incorporating fibrosis by investigators blinded to procedural findings. Rapid pacing was applied in silico to induce LAFL. In each LAFL, we represented reentrant wave propagation as an electric flow network and identified the "minimum cut" (MC), which was the smallest amount of tissue that separated the flow into 2 discontinuous components. In silico ablation was applied at MCs, and targets were compared to those that terminated LAFL during catheter ablation.
Patient-specific atrial models were successfully generated from patient scans. LAFL was induced in 7 of 10 models. Ablation of MCs terminated LAFL in 4 models and produced new, slower LAFL morphologies in the other 3. For the latter cases, flow analysis was repeated to identify MCs of emergent LAFLs. Ablation of these MCs terminated emergent LAFLs. The MC-based ablation lesions in simulations were similar in length and location to ablation targets that terminated LAFL during catheter ablation for these 7 patients.
Personalized atrial simulations can predict ablation targets for LAFL. These simulations provide a powerful tool for planning ablation procedures and may reduce procedural times and complications.
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