Successful flutter catheter ablation through the azygos continuation due to an interrupted inferior vena cava.

Inferior vena cava IVC is a crucial route for catheter access (both directly to the right heart and indirectly through a transeptal puncture to the left heart, used in most electrophysiological procedures). However, interrupted IVC is a real challenge to traditional arrythmia ablation approaches, compromising in certain cases the success of the procedure. A well-developed azygos continuation offers an alternative pathway, bypassing the interrupted segment of the IVC. We report the case of a 60 years old female, who underwent catheter ablation of a counterclockwise flutter. During the procedure, she was discovered to have an uncommon anatomical venous pathway from femoral access to the right heart chambers. She was diagnosed to have an interruption of the supra-renal segment of the inferior vena cava with azygos continuation. Radiofrequency ablation of the cavotricuspid isthmus was successfully performed through the azygos continuation.

Lessons from ablation responses to preferential wavefront in typical atrial flutter.

BACKGROUND: The heterogeneous conduction properties through the cavotricuspid isthmus (CTI) in typical atrial flutter (AFL) have not yet been well elucidated. OBJECTIVE: We sought to investigate preferential conduction through the CTI and the efficacy of ablation targeting preferential wavefront (PW) guided by ultra-high-resolution mapping. METHODS: In retrospective study, 28 patients were enrolled. Wavefront propagation patterns through the CTI and ablation responses at the location of PW were evaluated. In the following prospective study, 23 patients with predominant PW across the CTI were enrolled and assigned to the arm of PW prior ablation and the arm of conventional ablation. RESULTS: Five activation patterns were noticed in the retrospective study. The termination sites were exactly located at the PW in 18 of 28 patients (64.3%). The width of the PW in direct termination group was significantly narrower than that in the CL prolongation before termination group (16.6 ± 1.0 mm vs. 23.3 ± 3.4 mm, respectively, p = 0.025). In the prospective study, the voltage of PW region was significantly higher than non-PW regions both from unipolar and bipolar mapping. 21 of 23 patients (91.3%) were terminated at PW. AFL could no longer be induced immediately after termination. The time from radiofrequency application to AFL termination and to achieve bidirectional conduction block was significantly shorter in PW prior ablation arm than that in conventional ablation group (p < 0.05). CONCLUSIONS: Ablation targeting the PW first could be more efficient to terminate typical AFL and to achieve the endpoint of bidirectional conduction block.

Pericardial hydatid cysts presenting with atrial flutter and mitral regurgitation.

Despite being a rare phenomenon, pericardial hydatid cysts present unique diagnostic challenges and require a multimodality imaging as well as a multidisciplinary approach for a curative management. The authors here present a case of a middle aged man who was referred to them for management of new onset atrial flutter with mitral regurgitation.

Outcome after ablation of atypical atrial flutter: Is induction a feasible approach?

Background: Atypical atrial flutter (AAF) is an increasingly relevant clinical problem. Despite advancements in mapping and ablation techniques, the general management of these patients remain challenging especially when mapping cannot be performed during ongoing arrhythmia. There are no data whether induction of AAF is a feasible approach in these cases. Methods: We retrospectively analyzed patients who underwent catheter ablation of AAF and compared procedural results between patients with ongoing tachycardia when starting the procedure and patients with induced AAF. Results: We analyzed 97 ablation procedures performed in 76 patients with a mean follow-up of 13.2 ± 12.2 months. In 68 procedures (70.1 %) AAF was ongoing at the beginning of the procedure and in 29 cases (29.9 %) AAF had to be induced.There was no statistically significant difference regarding acute procedural success. The recurrence rate of any arrhythmia during follow-up was significantly higher after ablation of ongoing AAF compared to induced AAF (63.2 % vs. 42.9 %; p = 0.047) driven by a significant higher rate of AAF-recurrence (57.4 % vs. 34.5 %; p = 0.039). The number of ablated tachycardias per patient as well as the number of de-novo tachycardias found during re-ablation showed no significant difference between both groups. Conclusion: Starting a procedure with ongoing arrhythmia did not result in better short- or mid-term outcome in patients undergoing AAF ablation. Furthermore, based on our results inducing AAF seems a legitimate approach for AAF ablation in patients presenting in sinus rhythm.

Evaluation of risk factors for long-term atrial fibrillation development in patients undergoing typical atrial flutter ablation: a multicenter pilot study.

BACKGROUND: Atrial flutter (AFL) and atrial fibrillation (AF) are the most commonly detected supraventricular arrhythmias and share similar pathophysiological mechanisms. After the successful ablation of AFL, AF frequently occurs in the long-term follow-up. As emphasized in some studies, certain mechanisms seem to predispose to the development of AF in AFL patients, and approximately 20% of these patients have accompanying AFL. PURPOSE: We aimed to analyze independent risk factors that predict the development of AF in patients who underwent typical AFL ablation. METHODS: This was a multicenter, cross-sectional, and retrospective study. A total of 442 patients who underwent typical AFL ablation at three different centers between January 1, 2018 and January 1, 2022 were included retrospectively. After the ablation procedure the patients were divided into those who developed AF and those who did not. The patients were followed up for an average of 12 (4-20) months. In the post-procedural period, atrial arrhythmias were investigated with 24­h Holter and ECG at 1 month, 6 months, and 12 months and then at 6­month intervals thereafter. RESULTS: Overall, AF developed in 206 (46.6%) patients in the long-term follow-up. Age, hypertension (HT), obstructive sleep apnea syndrome (OSAS), previous cerebrovascular accident (CVA), left atrium anteroposterior diameter, severe mitral regurgitation, hemoglobin, blood glucose, and HbA1c values were found to be significant in univariable analysis. According to multivariable analysis, HT (p = 0.014; HR: 1.483 [1.084-2.030]), OSAS (p = 0.008; HR: 1.520 [1.117-2.068]) and previous CVA (p = 0.038; HR: 1.749 [1.031-2.968]) were independently associated with the development of AF in AFL patients who underwent ablation procedure. CONCLUSION: In the present study, we found that HT, OSAS, and previous CVA were independently correlated with the development of AF in the long-term follow-up of patients who underwent typical AFL ablation. We consider that AFL patients with such risk factors should be followed up closely following cavotricuspid isthmus ablation for the development of AF.

Prevalence of demoralization and depressive symptoms in a sample of patients with supraventricular tachyarrhythmias: preliminary results.

Introduction: Supraventricular tachyarrhythmias (ST) are the most common cardiac arrhythmias. Little is known about the potential impact of demoralization, which is considered as partially distinct from depression, on the course of ST. A correct assessment of both depressive symptoms and demoralization appears relevant for the treatment of these cardiac diseases, potentially influencing their course. Methods: The sample consisted of 110 subjects affected by different ST, such as atrial fibrillation (AF), atrial flutter (AFL) and paroxysmal supraventricular tachycardia (PSVT). They all underwent a psychiatric evaluation; the Italian version of 9-item Patient Health Questionnaire (PHQ-9) and the Italian version of Demoralization Scale (DS) were administered. Descriptive statistics, pairwise comparisons, and correlational analysis have been implemented. Results: 26 individuals (23.6%) presented high levels of demoralization. Of these, 20 (76.9%) had a diagnosis of AF and six patients (23.1%) received a diagnosis of other ST. No differences in demoralization levels resulted in regard of sex, cardiac diagnoses and anticoagulant therapies. Amongst people with high levels of demoralization, 13 (50%) received no formal psychiatric diagnosis, and 12 (46.2%) showed moderate/severe depressive symptoms. Demoralization levels and PHQ-9 scores showed a significant positive correlation in the whole sample (r=0.550, p<0.001). Discussion: The present study found that in a sample of patients suffering from ST, high levels of demoralization were more frequent than clinically relevant depressive symptoms. We propose that demoralization and depression show partially distinguished psychopathological features, potentially associated with different therapeutic trajectories.

Anatomic obstacles in cavotricuspid isthmus detected by modified 2D transthoracic echocardiography and long-term outcomes in radiofrequency ablation of typical atrial flutter.

BACKGROUND: Although radiofrequency ablation of the cavotricuspid isthmus (CTI), responsible for sustaining atrial flutter, is a highly effective procedure, in extended patients' observations following this procedure, more than every tenth becomes unsuccessful. Therefore, this study aimed to provide helpful information about the anatomy of the CTI in transthoracic echocardiography, which can aid in better planning of the CTI radiofrequency ablation in patients with typical atrial flutter. MATERIALS AND METHODS: 56 patients with typical atrial flutter after radiofrequency ablation were evaluated at the end of the 24-month observation period. With substernal modified transthoracic echocardiographic (mTTE) evaluation, we identified four main anatomical obstacles impeding radiofrequency ablation. These obstacles were tricuspid annular plane systolic excursion, cavotricuspid isthmus length, cavotricuspid isthmus morphology, and the presence of a prominent Eustachian ridge/Eustachian valve. All intraprocedural radiofrequency ablation data were collected for analysis and correlated with anatomical data. RESULTS: In the 24-month observation period, freedom from atrial flutter was 67.86%. The mean length of the isthmus was 30.34 ± 6.67 mm. The isthmus morphology in 56 patients was categorized as flat (n = 27; 48.2%), concave (n = 10; 17.85%), and pouch (n = 19, 33.9%). A prominent Eustachian ridge was observed in 23 patients (41.1%). Lack of anatomical obstacles in mTTE evaluation resulted in 100% efficacy, while the presence of at least two obstacles significantly increased the risk of unsuccessful ablation with more than two (OR 12.31 p = 0.01). Generally, 8 mm electrodes were the most effective for non-difficult CTI, while 3.5 mm electrodes used with a 3D system had highest performance for complex CTI. Notably, aging was the only factor that worsened the long-term outcome (OR 1.07 p = 0.044). CONCLUSIONS: Preoperative usage of mTTE evaluation helps predict difficulty in cavotricuspid isthmus radiofrequency ablation, thus allowing better planning of the radiofrequency ablation strategy using the most accurate radiofrequency ablation electrode.

Updates in Arrhythmia Management in Adult Congenital Heart Disease.

Arrhythmias are highly prevalent in adults with congenital heart disease. For the clinician caring for this population, an understanding of pathophysiology, diagnosis, and management of arrhythmia is essential. Herein we review the latest updates in diagnostics and treatment of tachyarrhythmias and bradyarrhythmias, all in the context of congenital anatomy, hemodynamics, and standard invasive palliations for congenital heart disease.

A late-onset arrhythmogenic right ventricular cardiomyopathy unveiled by supraventricular tachycardia: Case report.

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a rare myocardial genetic disease that leads to heart failure and sudden cardiac death. The diagnosis of ARVC remains challenging given its variable presentation. A 66-year-old woman was admitted to our cardiac intensive care unit for the management of a left heart failure flare-up with an atrial flutter, which remains an atypical mode of the revelation of arrhythmogenic right ventricular cardiomyopathy (ARVC) retained based the association of genetic predisposition, the presence of repolarization abnormalities on electrocardiogram (EKG), the occurrence of an episode of sustained ventricular tachycardia and imaging data. ARVC is a condition with varying expressions, severity, and progression. Early detection, careful monitoring, and appropriate management are crucial in improving outcomes for individuals with ARVC.

Comprehensive Analysis of Anticoagulant Therapy in Patients With Isolated Atrial Flutter.

Limited comparative data exist regarding the risk of cardiogenic emboli in patients with isolated atrial flutter (AFL). Some studies suggest a lower complication risk in AFL than atrial fibrillation (Afib); however, methodologic limitations and conflicting reports necessitate a comprehensive investigation. Our analysis proposes that isolated AFL carries a lower risk of ischemic events and left atrial thrombus formation than AFib. Importantly, we caution against applying stroke risk assessment approaches designed for AFib to patients with AFL because it may lead to harmful overestimations and unnecessary anticoagulant prescriptions. Furthermore, we highlight the current lack of sufficient data to determine the overall clinical benefit of prolonged anticoagulant therapy in patients with isolated AFL, especially when CHA2DS2-VASc index values are below 4. This review challenges existing perceptions, offering insights into the nuanced risk profiles of the transitional nature of isolated AFL because of the high incidence of AFib development within a year of AFL diagnosis. Tailored risk assessments and further research are essential for precise clinical decision-making in this dynamic landscape.

A case of biatrial tachycardia involving the intercaval bundle with assumed dual loop reentry.

Epicardial connections provided the anatomical substrate for the biatrial reentry circuit. The connections between the right atrium and right pulmonary vein were called "intercaval bundle," and there are few reports of atrial flutter related to this bundle. We present a case of a biatrial tachycardia, involving the intercaval bundle.

Paradoxical generator impedance behavior during catheter ablation in a patient with severe polycythemia.

An extremely high generator impedance in the blood pool can be observed in a patient with severe polycythemia. However, ablation can be performed safely as long as the generator impedance during contact with the myocardial tissue is within acceptable limits.

Nationwide Trends in Hospitalizations for Atrial Fibrillation and Flutter in the United States before and during the Outbreak of the COVID-19 Pandemic.

Background/Objectives: Atrial fibrillation (AF) and flutter (AFL) are the most common cardiac arrhythmias worldwide. Cardiovascular complications are a common manifestation of acute and post-acute COVID-19 infection. We aimed to analyze the nationwide trends in clinical characteristics and outcomes of patients hospitalized for AF/AFL before and during the COVID-19 outbreak in the U.S. Methods: This study is a retrospective analysis of patients, aged 18 and older, hospitalized for AF/AFL in the U.S. between 2016 and 2020. We drew data from the National Inpatient Sample (NIS) database. Baseline sociodemographic and clinical data, as well as outcomes including stroke, acute coronary syndrome (ACS), and mortality, were analyzed. Multivariable analysis was performed to identify independent associations between the different clinical and demographic characteristics and the composite endpoint of Mortality/ACS/Stroke. Results: An estimated total of 2,163,699 hospitalizations for AF/AFL were identified. The hospitalization volume between 2016 and 2019 was stable, averaging 465,176 a year, followed by a significant drop to 302,995 in 2020. Patients' median age was 72 years (IQR 62-80), 50.9% were male, and 81.5% were white. The composite endpoint steadily increased from 6.5% in 2016 to 11.8% in 2020 (Ptrend < 0.001). In a multivariable regression analysis, age > 75 (OR: 1.35; 95% CI 1.304-1.399, p < 0.001), ischemic heart disease (OR: 1.466; 95% CI: 1.451-1.481; p < 0.001), and chronic kidney disease (OR: 1.635; 95% CI: 1.616-1.653; p < 0.001) were associated with the composite endpoint. COVID-19 was associated with the composite endpoint outcome in the year 2020 (OR: 1.147; 95% CI: 1.037-1.265; p = 0.007). Conclusions: Hospitalization for AF/AFL dropped significantly during the first year of the COVID-19 pandemic outbreak, possibly due to patients' avoidance of hospital visits. The composite endpoint of Mortality/ACS/Stroke uptrended significantly during the study period. COVID-19 was shown to be independently associated with the adverse composite outcome Mortality/ACS/Stroke.

Estimating the burden of atrial fibrillation and atrial flutter with projection to 2050 in Iran.

Atrial fibrillation (AF)/atrial flutter (AFL) is the most common cardiac tachyarrhythmia, with an increasing trend in its burden in recent years. However, the burden of AF/AFL in Iran remains unclear. This study aimed to estimate the burden of AF/AFL and its attributable risk factors from 1990 to 2019 at national and subnational levels. Using the comparative risk assessment method of the Global Burden of Disease (GBD) Study 2019, we extracted data on AF/AFL incidence, prevalence, deaths, disability-adjusted life years (DALYs), and their age-standardized rates from 1990 to 2019 and analyzed them based on by age, sex, and socio-demographic index (SDI). The percentage contribution of AF/AFL major risk factors was calculated. Moreover, the AF/AFL burden in 2050 was projected using the United Nations world population prospect data. In 2019, there were 339.1 (259.4-433.7) thousand AF/AFL patients in Iran, with 30.2 (23.2-38.5) thousand new cases, 1.7 (1.5-2) thousand deaths and 48 (37.7-60.5) thousand DALYs. Females and 50-69-year-old patients recorded a higher burden for AF/AFL; however, the increasing trend was more pronounced in males and more than 85-year-old patients. High systolic blood pressure and elevated body mass index (BMI) were the predominant attributable risk factors for AF/AFL-related deaths and DALYs. It is estimated that in 2050, the number of AF/AFL patients will increase to 1.1 million people, the incidence of AF/AFL will increase to 91 thousand patients, and the number of AF/AFL-related deaths and DALYs will surge to 7.2 and 170.8 thousand, respectively. Despite advancements in prevention and treatment, AF/AFL remains a major public health problem in Iran. Given its largely preventable and treatable nature, more cost-effective strategies are required to target modifiable risk factors, especially within susceptible age and sex groups.

Case Report: Epi-endocardial bridges in refractory cavotricuspid isthmus-dependent atrial flutter: technical analysis of epi-endocardial breakthrough.

Background: Typical isthmus-dependent atrial flutter (AFL) is traditionally treated through radiofrequency (RF) ablation to create a bidirectional conduction block across the cavo-tricuspid isthmus (CTI) in the right atrium. While this approach is successful in many cases, certain anatomical variations can present challenges, making CTI ablation difficult. Methods: We enrolled four patients with typical counter-clockwise AFL who displayed an epicardial bridge at the CTI. Patients underwent high-resolution mapping of the right atrium and CTI ablation. Results: Post-mapping identified areas of early focal activation outside the lesion line which suggested the presence of an epi-endocardial bridge with an endocardial breakthrough, confirmed by recording a unipolar rS pattern on electrograms at that site. A stable CTI block was achieved in all patients only after ablation at the site of the epi-endocardial breakthrough. Conclusions: The presence of an epicardial bridge at the CTI, allowing conduction to persist despite endocardial ablation, should be considered in challenging cases of CTI-dependent AFL. Understanding this phenomenon and utilizing appropriate mapping and ablation techniques are essential for achieving successful and lasting CTI block.

Cavotricuspid Isthmus-Dependent Atrial Flutter. Beyond Simple Linear Ablation.

The demonstration of a peritricuspid circular movement with a zone of slow conduction in the cavotricuspid isthmus, together with the high efficacy of linear ablation and widely accepted acute endpoints, has established typical flutter as a disease with a well-defined physiopathology and treatment. However, certain aspects regarding its deeper physiopathology, ablation targets, and methods for verifying the results remain to be clarified. While current research efforts have primarily been focused on the advancement of effective ablation techniques, it is crucial to continue exploring the intricate electrophysiological, ultrastructural, and pharmacological pathways that underlie the development of atrial flutter. This ongoing investigation is essential for the development of targeted preventive strategies that can act upon the specific mechanisms responsible for the initiation and maintenance of this arrhythmia. In this work, we will discuss less ascertained aspects alongside the most widely recognized general data, as well as the most recent or less commonly used contributions regarding the electrophysiological evaluation and ablation of typical atrial flutter. Regarding electrophysiological characteristics, one of the most intriguing findings is the presence of low voltage zones in some of these patients together with the presence of a functional, unidirectional line of block between the two vena cava. It is theorized that episodes of paroxysmal atrial fibrillation can trigger this line of block, which may then allow the onset of stable atrial flutter. Without this, the patient will either remain in atrial fibrillation or return to sinus rhythm. Another of the most important pending tasks is identifying patients at risk of developing post-ablation atrial fibrillation. Discriminating between individuals who will experience a complete arrhythmia cure and those who will develop atrial fibrillation after flutter ablation, remains essential given the important prognostic and therapeutic implications. From the initial X-ray guided linear cavotricuspid ablation, several alternatives have arisen in the last decade: electrophysiological criteria-directed point applications based on entrainment mapping, applications directed by maximum voltage criteria or by wavefront speed and maximum voltage criteria (omnipolar mapping). Electro-anatomical navigation systems offer substantial support in all three strategies. Finally, the electrophysiological techniques to confirm the success of the procedure are reviewed.

Thromboembolism after coronavirus disease 2019 vaccination in atrial fibrillation/flutter: a self-controlled case series study.

BACKGROUND AND AIMS: Concerns about the safety of coronavirus disease 2019 (COVID-19) vaccines in patients with atrial fibrillation/flutter (AF/AFL) have arisen due to reports of thrombo-embolic events following COVID-19 vaccination in the general population. This study aimed to evaluate the risk of thrombo-embolic events after COVID-19 vaccination in patients with AF/AFL. METHODS: This was a modified self-controlled case-series study using a comprehensive nationwide-linked database provided by the National Health Insurance Service in South Korea to calculate incidence rate ratios (IRRs) of thrombo-embolic events. The study population included individuals aged ≥12 years who were either vaccinated (e.g. one or two doses) or unvaccinated during the period from February to December 2021. The primary outcome was a composite of thrombo-embolic events, including ischaemic stroke, transient ischaemic attack, and systemic thromboembolism. The risk period was defined as 0-21 days following COVID-19 vaccination. RESULTS: The final analysis included 124 127 individuals with AF/AFL. The IRR of thrombo-embolic events within 21 days after COVID-19 vaccination, compared with that during the unexposed control period, was 0.93 [95% confidence interval (CI) 0.77-1.12]. No significant risk variations were noted by sex, age, or vaccine type. However, patients without anticoagulant therapy had an IRR of 1.88 (95% CI 1.39-2.54) following vaccination. CONCLUSIONS: In patients with AF/AFL, COVID-19 vaccination was generally not associated with an increased risk of thrombo-embolic events. However, careful individual risk assessment is required when advising vaccination for those not on oral anticoagulant, as these patients exhibited an increased risk of thrombo-embolic events post-vaccination.

Global burden of atrial fibrillation/atrial flutter and its attributable risk factors from 1990 to 2021.

AIMS: To devise effective preventive measures, a profound understanding of the evolving patterns and trends in atrial fibrillation (AF) and atrial flutter (AFL) burdens is pivotal. Our study was designed to quantify the burden and delineate the risk factors associated with AF and AFL across 204 countries and territories spanning 1990-2021. METHODS AND RESULTS: Data pertaining to AF and AFL were sourced from the Global Burden of Disease Study 2021. The burden of AF/AFL was evaluated using metrics such as incidence, disability-adjusted life years (DALYs), deaths, and their corresponding age-standardized rates (ASRs), stratified by age, sex, socio-demographic index (SDI), and human development index (HDI). The estimated annual percentage change was employed to quantify changes in ASRs. Population attributable fractions were calculated to determine the proportional contributions of major risk factors to age-standardized AF/AFL deaths. This analysis encompassed the period from 1990 to 2021. Globally, in 2021, there were 4.48 million incident cases [95% uncertainty interval (UI): 3.61-5.70], 8.36 million DALYs (95% UI: 6.97-10.13) and 0.34 million deaths (95% UI: 0.29-0.37) attributed to AF/AFL. The AF/AFL burden in 2021, as well as its trends from 1990 to 2021, displayed substantial variations based on gender, SDI quintiles, and geographical regions. High systolic blood pressure emerged as the leading contributor to age-standardized AF/AFL incidence, prevalence, death, and DALY rate globally among all potential risk factors, followed closely by high body mass index. CONCLUSION: Our study underscores the enduring significance of AF/AFL as a prominent public health concern worldwide, marked by profound regional and national variations. Despite the substantial potential for prevention and management of AF/AFL, there is a pressing imperative to adopt more cost-effective strategies and interventions to target modifiable risk factors, particularly in areas where the burden of AF/AFL is high or escalating.