Atrial Flutter Patients Research Articles

Influence of common zones of low-amplitude activity on the mechanism and treatment of atrial arrhythmias

Background: The treatment of left atrial flutter is a problem that requires a deep understanding of the underlying complex mechanism of arrhythmia. Although a considerable experience exists already in understanding the mechanisms underlying atrial flutter after ablation or surgery, little is known about atypical forms of atrial flutter in patients who have not previously undergone ablation or other cardiac surgery.
 Clinical case description: We present a clinical case of interventional treatment of a patient with atypical atrial flutter who had not previously undergone surgical or interventional heart surgery. This clinical observation demonstrates the role of common zones of low-amplitude activity on the mechanism and treatment of atrial arrhythmias. Widespread areas of low-amplitude activity in the left atrium can create barriers to the propagation of excitation, which can cause atypical atrial flutter.
 Conclusion: When performing a surgical intervention, high-density mapping will help to visualize the mechanism of this arrhythmia. Understanding the mechanism of atypical atrial flutter will help to minimize the RF exposure during the treatment.

The Chinese expert recommendations on the clinical use of dronedarone

Dronedarone, a class Ⅲ antiarrhythmic drug, is a deiodinated benzofuran derivative of amiodarone. It has similar antiarrhythmic effects with amiodarone, but much lesser adverse effects than amiodarone, particularly in those outside the heart. It is suggested to use dronedarone for the rhythm control of atrial fibrillation/flutter, for it has been shown to prevent the recurrence of atrial fibrillation/flutter and reduce rehospitalization in patients with paroxysmal or persistent atrial fibrillation/flutter. Dronedarone is not recommended for the rhythm control in patients with long-term persistent atrial fibrillation or permanent atrial fibrillation, and atrial flutter or atrial fibrillation patients with reduced ejection fraction. Liver function, electrolyte tests and an electrocardiogram should be performed before and after the drug initiation. Potential interactions with other kinds of drugs have to be taken into consideration as well.

Comparison of clockwise and counterclockwise right atrial flutter using high-resolution mapping

Abstract Background To the best of our knowledge, few studies have been performed that explore the electrophysiological differences between clockwise (CW) and counterclockwise (CCW) right atrial (RA) cavotricuspid isthmus (CTI)-dependent atrial flutter (AFL) using the high-resolution Rhythmia mapping system. Objectives. Accordingly, our prospective cohort study, sought to compare CW and CCW CTI-dependent AFL in preselected pure right AFL patients (pts) using the ultra-high-definition (ultra-HD) Rhythmia mapping system. The study also aimed to mathematically develop a cartography model based on automatic velocity RA measurements to identify electrophysiological AFL specificities. Methods and results Between October 2019 and July 2020, 33 patients were recruited. The mean age was 71±13 years old. No difference was found concerning clinical variables between CCW AFL and CW AFL or regarding left ventricular ejection fraction (LVEF) (55.5±10 vs. 56.6±12; p=0.76). The AFL cycle length was very similar (248±20 vs. 252±28 ms; p=0.6). The sinus venosus (SV) block line was present in 32/33 of cases (97%) and no significant difference was found between CCW and CW CTI AFL (100% vs. 91%; p=0.7). No line was localized in the region of the crista terminalis (CT). A superior gap was present in the posterior line in 14/31 (45.2%) but this was similarly present in CCW AFL, when compared to CW AFL (10/22 [45.5%] vs. (4/10 [40%]); p=0.9). When present, the extension of the posterior line of block was observed in 18/31 pts (58%) without significant differences between CCW and CW CI AFL (12/22 [54.5%] vs. (6/10 [60%]) (p=.9) The Eustachian ridge line of block was similarly present in both groups (82% [18/22] vs. 45.5% [5/11]; p=0.2). The absence of the Eustachian ridge line of block led to significantly slowed velocity in this area (28±10cm/s; n=8),and the velocities were similarly altered between both groups (26±10 [4/22] vs. 29.8±11cm/s [4/11]; p=0.6). We created mathematical, three-dimensional RA reconstruction-velocity model measurements. In each block localization, when the block line was absent, velocity was significantly slowed (≤20cm/s). A systematic slowdown in conduction velocity was observed at the entrance and exit of the CTI in 100% of cases. This alteration to the conduction entrance was localized at the lateral side of the CTI for the CCW AFL and at the septal side of the CTI for CW AFL. The exit-conduction alteration was localized at the CTI septal side for the CCW AFL and at the CTI lateral side for the CW AFL. The only differences between CW and CCW AFL concerned activation patterns. Conclusions The ultra-HD Rhythmia mapping system confirmed the absence of significant electrophysiological differences between CCW and CW AFL. The mechanistic posterior SV and Eustachian ridge block lines were confirmed in each arrhythmia. A systematic slowing down at the entrance and exit of the CTI was demonstrated in both CCW and CW AFL, but in reverse positions. Funding Acknowledgement Type of funding sources: None.

Antithrombotic therapy and bleeding complications in patients with atrial fibrillation and active cancer

Abstract Background Little is known about the extent to which an active cancer diagnosis increases bleeding and thromboembolic risks in atrial fibrillation (AF) patients. Data on major bleeding rates per antithrombotic management strategy are lacking in AF patients with active cancer. Purpose To examine the incidence rates of major bleeding per antithrombotic treatment in AF patients with active cancer and to examine whether cancer type impacts major bleeding and thromboembolic risks. Methods We used Danish population-based health care databases to conduct this cohort study. We included all incident AF (including atrial flutter) patients aged ≥50 years between January 1st 1995 and December 31st 2016, out of whom we identified AF patients who subsequently developed cancer. We used International Classification of Diseases 10th Revision codes to identify data on cancer type and outcomes (i.e. major bleeding, arterial and venous thromboembolism). We used Anatomical Therapeutic Chemical codes to provide information on antithrombotic treatment (e.g. no anticoagulant treatment, platelet inhibitors, vitamin K antagonists, direct oral anticoagulants, or a combination of antithrombotic drugs) which was evaluated as a time-dependent variable. The follow-up started from the incident cancer diagnosis until the occurrence of an outcome, death or the end of the two year follow-up. Incidence rates per 100 patient-years and adjusted hazard ratios were computed. Results 22,996 AF patients with a subsequent incident cancer diagnosis were included in the study. These patients had higher major bleeding and thromboembolic risk compared to those without cancer, with adjusted HRs of 2.11 (1.99–2.23) and 1.36 (1.27–1.44), respectively (Figure 1). Highest bleeding risk was observed for intracranial and respiratory cancer, while haematological and respiratory cancer were associated with highest thromboembolic risk. Bleeding risk increased with increasing number of antithrombotic drugs and was higher in AF patients with active cancer compared to those without, across all exposure categories (Figure 2). Conclusions Patients with AF and active cancer are at increased risk of major bleeding and thromboembolisms than those without cancer. Treatment with dual or triple antithrombotic therapy in AF patients with active cancer showed very high bleeding rates. Funding Acknowledgement Type of funding sources: None.

A new electrophysiological triad for atrial flutter critical isthmus identification and localization

Abstract Introduction In a previous retrospective study it was demonstrated that an electrophysiological triad was able to identify critical isthmus in atrial flutter (AFL) patients. This triad is based in the Carto® electroanatomical mapping (EAM) version 7, which displays a histogram of the local activation times (LAT) of the tachycardia cycle length (TCL), in addition to the activation and voltage maps. This study aimed to prospectively assess the ability of an electrophysiological triad to identify and localize the AFL's critical isthmus. Methods Prospective analysis of a unicentric registry of individuals who underwent left AFL ablation with Carto® EAM. All patients with non-left AFL, lack of high-density EAM, less than 2000 collected points or lack of mapping in any of the left atrium walls or structures were excluded. Ablation sites of arrhythmia termination were compared to an electrophysiological triad constituted by: areas of low-voltage (0.05 to 0.3mV), sites of deep histogram valleys (LAT-Valleys) with less than 20% density points relative to the highest density zone and a prolonged LAT-Valley duration that included 10% or more of the TCL. The longest LAT-Valley was designated as the primary valley, while additional valleys were named as secondary. Results A total of 12 patients (9 men, median age 72 IQR 67–75 years) were included. All patients presented with left AFL and 67% had a previous atrial fibrillation and/or flutter ablation. The median TCL and number collected points were 250 (230–290) milliseconds and 3150 (IQR 2340–3870) points, respectively. All AFL presented with at least 1 LAT-Valley in the analysed histograms, which corresponded to heterogeneous low-voltage areas (0.05 to 0.3mV) and encompassed more than 10% of TCL. Eleven of the 12 patients presented with at least 1 secondary LAT-Valley. All arrhythmias were effectively terminated after undergoing radiofrequency ablation in the primary or the secondary LAT-Valley location. Conclusion In a prospective analysis, an electrophysiological triad was able to identify the AFL critical isthmus in all patients. Further studies are needed to assess the usefulness of this algorithm to improve catheter ablation outcomes. Funding Acknowledgement Type of funding sources: None.

Prediction of Recurrent Atrial Tachyarrhythmia After Receiving Atrial Flutter Ablation in Patients With Prior Cardiac Surgery for Valvular Heart Disease.

Background: Surgical scars cause an intra-atrial conduction delay and anatomical obstacles that facilitate the perpetuation of atrial flutter (AFL). This study aimed to investigate the outcome and predictor of recurrent atrial tachyarrhythmia after catheter ablation in patients with prior cardiac surgery for valvular heart disease (VHD) who presented with AFL.Methods: Seventy-two patients with prior cardiac surgery for VHD who underwent AFL ablation were included. The patients were categorized into a typical AFL group (n = 45) and an atypical AFL group (n = 27). The endpoint was the recurrence of atrial tachyarrhythmia during follow-up. A multivariate analysis was performed to determine the predictor of recurrence.Results: No significant difference was found in the recurrence rate of atrial tachyarrhythmia between the two groups. Patients with concomitant atrial fibrillation (AF) had a higher recurrence of typical AFL compared with those without AF (13 vs. 0%, P = 0.012). In subgroup analysis, typical AFL patients with concomitant AF had a higher incidence of recurrent atrial tachyarrhythmia than those without it (53 vs. 14%, P = 0.006). Regarding patients without AF, the typical AFL group had a lower recurrence rate of atrial tachyarrhythmia than the atypical AFL group (14 vs. 40%, P = 0.043). Multivariate analysis showed that chronic kidney disease (CKD) and left atrial diameter (LAD) were independent predictors of recurrence.Conclusions: In our study cohort, concomitant AF was associated with recurrence of atrial tachyarrhythmia. CKD and LAD independently predicted recurrence after AFL ablation in patients who have undergone cardiac surgery for VHD.

A Population-Based Study of Unexplained/Lone Atrial Fibrillation: Temporal Trends, Management, and Outcomes

BackgroundPrevious studies on lone/unexplained atrial fibrillation and atrial flutter (AF) did not exclude patients with contemporary secondary AF triggers. We characterized unexplained AF using a strict definition, and compared it to secondary AF. MethodsIn this population-based study, unexplained AF was defined by the lack of any identifiable triggering medical/surgical diagnosis. Comparisons by AF type (unexplained vs secondary), age-of-onset (≤ / > 65 years), and sex were undertaken. Data were acquired by linking 6 population databases maintained by the Alberta Ministry of Health over a 9-year period (April 2006 to March 2015). The primary composite outcome of stroke, transient ischemic attack, thromboembolism, and/or death was assessed. ResultsThere were 33,150 incident AF diagnoses identified, including 1145 patients (3.5%) with unexplained AF, 931 (81.2%) of whom were aged ≤ 65 years (2.8% of diagnoses, and 79% male). Patients with unexplained AF less often received rate/rhythm-control drugs (P < 0.0001), but they more often underwent electrical cardioversion (P < 0.0001) vs secondary AF patients. Men were younger at unexplained AF diagnosis (45 [interquartile range: 34-59] vs 58 [interquartile range: 40-69] years; P < 0.001). After adjusting for age at diagnosis, there were no sex-based differences in the primary outcome. Event-free survival in young unexplained AF (age ≤ 65 years) was 99.4% at 1 year and 98.3% at 3 years. At 3 years, hospitalization(s)/emergency visit(s) for noncardiovascular reasons and for AF occurred in 56.6% and 23.8% of these patients, respectively. ConclusionsUsing a strict contemporary definition of unexplained AF, this study shows that the condition is rare, predominantly male, and has excellent event-free survival. However, the high rate of acute hospital utilization after diagnosis is concerning.

Preventing atrial fibrillation by combined right isthmus ablation and cryoballoon pulmonary vein isolation in patients with typical atrial flutter: PAF-CRIOBLAF study.

BackgroundAlthough less common, typical atrial flutter shares similar pathophysiological roots with atrial fibrillation. Following successful cavo‐tricuspid isthmus ablation using radiofrequency, many patients, however, develop atrial fibrillation in the mid‐to‐long‐term. This study sought to assess whether pulmonary vein isolation conducted at the same time as cavo‐tricuspid isthmus ablation would significantly modify the atrial fibrillation burden upon follow‐up in patients suffering from typical atrial flutter.MethodsThis was a multicenter randomized controlled study involving typical atrial flutter patients with history of non‐predominant atrial fibrillation (1 atrial fibrillation episode only, in 67% of population) who were scheduled for cavo‐tricuspid isthmus radiofrequency ablation. Patients were randomly assigned to either undergo cavo‐tricuspid isthmus ablation alone or cavo‐tricuspid isthmus plus pulmonary vein isolation (CTI+). Pulmonary vein isolation was performed using cryoballoon technology. An outpatient consultation with ECG and 1‐week Holter monitoring was performed at 3, 6 months, 1 year, and 2 years postprocedure. The primary endpoint was atrial fibrillation recurrences lasting more than 30 s at 2 years postablation.ResultsOf the patients enrolled, 36 were included in each group. At 2‐year follow‐up, the atrial fibrillation recurrence rate was significantly higher in the CTI vs CTI+group (25/36, 69% vs. 12/36, 33% respectively; P < .001), with similar typical atrial flutter recurrence rates. There were no differences in undesirable events, except for transient phrenic nerve palsy reported from three CTI+patients (8.3%).ConclusionPulmonary vein isolation using cryoballoon technology was proven to significantly reduce the atrial fibrillation incidence at 2 years postcavo‐tricuspid isthmus ablation.

B-PO02-076 LONG-TERM CARDIOVASCULAR OUTCOME OF PATIENTS WITH ATRIAL FLUTTER UNDERGOING CATHETER ABLATION

The data regarding the long-term efficacy of cavotricuspid isthmus (CTI) dependent atrial flutter (AFL) ablation in terms of mortality and cardiovascular risk in AFL patients without AF history was still unclear. To determine the effectiveness of catheter ablation compared to conventional medical therapy for improving cardiovascular outcomes among patients with solitary AFL. We collected the data of 3,784 patients who were diagnosed with AFL without history of AF. After propensity matching for age, sex, comorbidities, and medications, we analyzed the outcome of total deaths, cardiac deaths, heart failure (HF), and AF admissions. Survival curve analysis showed that patients who had AFL ablation had a significantly better outcome in terms of total deaths, cardiovascular deaths, HF admissions, and AF admissions compared to medically treated patients (Figure). After adjusted with confounding factors, we identified that AFL ablation and future AF ablation reduced the risk for total deaths (HR: 0.68; 95% CI: 0.62-0.74, p< 0.001), cardiac deaths (HR: 0.78; 95% CI: 0.67-0.91, p=0.001), HF (HR 0.84; 95%: CI, 0.75-0.95, p=0.01), and AF admissions (HR 0.83; 95% CI 0.76-0.92, p<0.001). In patients who only received AFL ablation, we still found risk reduction of total death (HR: 0.65; 95% CI: 0.58-0.72, p<0.001), cardiac death (HR: 0.77; 95% CI: 0.64-0.92, p=0.003), and HF admissions (HR: 0.83; 95% CI: 0.72-0.96, p=0.01). AFL catheter ablation reduces the risk of total deaths, cardiac deaths, stroke admissions, HF admissions, and AF admissions in AFL patients without history of AF during a very long-term follow up.

Is it possible to expect left ventricular ejection fraction improvement in patients with known advanced heart diseases in the case of right atrial flutter treated by ablation?

Atrial flutter (AFL)-related tachycardia-induced cardiomyopathy (TICM) is a treatable cause of heart failure (HF). This study aims to explore the effect of AFL ablation on left ventricular (LV) function in right AFL patients with or without advanced heart diseases. Between January 2013 and December 2019, 149 patients underwent ablation for persistent AFL. Among them, 60 patients with persistent right atrial (RA) flutter had symptomatic HF and elevated natriuretic peptide levels. Group 1 consisted of 35 patients without advanced heart diseases, and group 2 consisted of 25 patients with prior history of ischemic cardiomyopathy (ICM), dilated cardiomyopathy (DCM) or surgery for valvular heart disease (VHD). Follow-up echocardiography was performed 6months later. Improvement of LV performance was defined as LV ejection fraction (EF) increase ≥50% of baseline EF without clinical HF symptoms or LVEF recovery to ≥60%. Group 2 had larger LV end-diastolic volume (LVEDV) and LV end-systolic volume than group 1. At follow-up, group 2 had larger LV end-systolic volume than group 1. Group 1 had more increase in LVEF than group 2 (21.7±15.2% vs 4.1±13.2%; P<.001). A receiver operating characteristic curve was constructed to determine the discrimination threshold of baseline LVEDV (137mL) in the overall study group for improvement of LV performance after ablation (P=.005). Successful ablation for right AFL could achieve more reversal of LV dysfunction in patients without advanced heart diseases. Pre-ablation LVEDV≥137mL was associated with no improvement of LV performance after ablation.

Risk factors for the occurrence of typical atrial flutter in patients undergoing pulmonary vein isolation

Highlights. Cavatricuspid isthmus ablation with pulmonary vein isolation is indicated to all patients with documented or intraoperatively induced typical atrial flutter. The preventive cavatricuspid isthmus ablation remains an issue of concern. The article discusses the risk factors for the onset of typical atrial flutter pulmonary vein isolation.Aim. To determine the need for preventive ablation of the cavatricuspid isthmus in patients referred to elective pulmonary vein isolation.Methods. 632 patients (the mean age of 63 years) were enrolled in a single-center retrospective study between 2015 to 2018. The inclusion criteria were as follows: paroxysmal AF, absence of documented AFL. All patients underwent pulmonary vein isolation. The exclusion criteria were as follows: a history of typical or AFL. The endpoints included major cardiovascular events, reoperations, occurrence of AFL. The primary endpoint was the absence of paroxysms of AF and AFL during the blind period. The secondary endpoint was the absence of AF paroxysms documented on the ECG or according to Holter monitoring data. The follow-up period was 12 months.Results. During the blind period, AF paroxysms were recorded in 148 (23.7%) patients. The efficiency of the operation within one year was 78.2% (494 patients). 138 patients (21.8%) had recurrent tachycardia. Of them, 28 patients (4.4%) were diagnosed with atrial fibrillation and others (17.4%) had AFL. Risk factors for AFL included COPD found in 18 patients (64.29%) (OR 25.4; CI 95%; 10.991-58.609), chronic heart failure in 20 patients (71.43%) (OR 7.434; CI 95%; 3.209-17.225), prolonged pr interval in 18 patients (64.29%) (OR 5.77; CI 95%; 2.288-14.5), a history of myocardial infarction in 6 patients (28.57%) (OR 6.591; CI 95%; 2.447-17.751), and smoking in 7 patients (67.86%) (OR 11.034; CI 95%; 4.849-25.112).Conclusion. Chronic obstructive pulmonary disease, chronic heart failure, a history of myocardial infarction, and smoking prolong right atrial conduction time, thereby increasing the risk of AFL in the postoperative period. Preventive cavatricuspid isthmus ablation should be considered in patients with risk factors for developing AFL.

Comparison of clockwise and counterclockwise right atrial flutter using high-resolution mapping and automated velocity measurements.

Only few studies have been performed that explore the electrophysiological differences between clockwise (CW) and counterclockwise (CCW) right atrial (RA) cavotricuspid isthmus (CTI)-dependent atrial flutter (AFL) using the high-resolution Rhythmia mapping system. We sought to compare CW and CCW CTI-dependent AFL in pure right AFL patients (pts) using the ultra-high-definition (ultra-HD) Rhythmia mapping system and we mathematically developed a cartography model based on automatic velocity RA measurements to identify electrophysiological AFL specificities. Thirty-three pts were recruited. The mean age was 71 ± 13 years old. The sinus venosus (SV) block line was present in 32/33 of cases (97%) and no significant difference was found between CCW and CW CTI AFL (100% vs. 91%; p = .7). No line was localized in the region of the crista terminalis (CT). A superior gap was present in the posterior line in 14/31 (45.2%) but this was similarly present in CCW AFL, when compared to CW AFL (10/22 [45.5%] vs. 4/10 [40%]; p = .9). When present, the extension of the posterior line of block was observed in 18/31 pts (58%) without significant differences between CCW and CW CI AFL (12/22 [54.5%] vs. 6/10 [60%]; p = .9) The Eustachian ridge line of block was similarly present in both groups (82% [18/22] vs. 45.5% [5/11]; p = .2). The absence of the Eustachian ridge line of block led to significantly slowed velocity in this area (28 ± 10 cm/s; n = 8), and the velocities were similarly altered between both groups (26 ± 10 [4/22] vs. 29.8 ± 11 cm/s [4/11]; p = .6). We created mathematical, three-dimensional RA reconstruction-velocity model measurements. In each block localization, when the block line was absent, velocity was significantly slowed (≤20 cm/s). A systematic slowdown in conduction velocity was observed at the entrance and exit of the CTI in 100% of cases. This alteration to the conduction entrance was localized at the lateral side of the CTI for the CCW AFL and at the septal side of the CTI for CW AFL. The exit-conduction alteration was localized at the CTI septal side for the CCW AFL and at the CTI lateral side for the CW AFL. The ultra-HD Rhythmia mapping system confirmed the absence of significant electrophysiological differences between CCW and CW AFL. The mechanistic posterior SV and Eustachian ridge block lines were confirmed in each arrhythmia. A systematic slowing down at the entrance and exit of the CTI was demonstrated in both CCW and CW AFL, but in reverse positions.

The effect of patient characteristics to the acute procedural success and long term outcome of atrial tachycardia and atrial flutter cases undergoing catheter ablation

Objective: In the present study we aimed to demonstrate clinical characteristics, predictors of procedural success and long term recurrence of atrial tachyarrhythmia patients undergoing catheter ablation (CA). Patients and Methods: Consecutive patients who had undergone CA due to an atrial tachyarrhythmia in a single centre arrhythmia unit between 2012 – 2020 were screened. Predictors of procedural success and recurrence were analysed by logistic regression. Results: Study population consisted of 299 consecutive patients (95 [31.8 %] atrial tachycardia, 204 [68.2 %] atrial flutter cases);163 ( 54.5 % ) were male; median age was 54 ( IQR; 42-64). Median follow up was 330 (IQR; 90 – 810) days. Atrial flutter patients were older and had more co-morbidities. Acute procedural success rate was 82.1 % vs. 77.0 % (p= 0.313) and recurrence was 9.3 % vs. 21.6 % (p=0.022) in atrial tachycardia (AT) and atrial flutter (AFL) cases respectively. History of valvular or congenital heart disease surgery, left atrium diameter and age were found to be independent predictors of failed ablation, recurrence and post-procedural atrial fibrillation. Conclusion: Age, left atrium diameter, valvular or congenital heart disease surgery are independent predictors for acute procedural success, recurrence and post-procedural atrial fibrillation in AT and AFL patients who undergo catheter ablation.

Different implication in dementia between patients with atrial flutter and atrial fibrillation: a national cohort study

Abstract Funding Acknowledgements Type of funding sources: None. Importance Atrial fibrillation (AF) has been reported with increasing the risk of stroke and dementia. Atrial flutter (AFL) is also a risk of stroke with different discrepancies in clinical outcome. Little is known about the difference in the risk of dementia between AF and AFL. Objective To investigate if the risk of dementia is difference between AF and AFL. Methods The patients with newly diagnosed AF and AFL during 2001–2013 was retrieved from Taiwan’s National Health Insurance Research Database. Patients with missing information, aged &amp;lt;20 years, history of valvular surgery, rheumatic heart disease, hyperthyroidism, and history of dementia were excluded. Propensity score matching (PSM) between AF and AFL was performed, which included patient comorbidities, past medical history, medications, and index date stratified by age. Primary outcome was defined as dementia at follow-up. Results A total of 232,425 AF and 7,569 AFL were eligible for analysis. After 4:1 PSM, we included 30,276 AF (aged 67.3 ± 15.7 years) and 100,065 AFL (aged 67.4 ± 16.0 years) for analysis. The risk of dementia was higher in AF patients compared with AFL patients (subdistribution HR (SHR)=1.52, 95% CI 1.39 - 1.66; p &amp;lt;0.0001) before PSM and still higher in AF patients (SHR = 1.14, 95% CI 1.04 to 1.25; p = 0.0064). The risk was higher in AF patients without previous stroke after PSM and there was no difference between AF and AFL patients with previous stroke history. Conclusions and relevance Our finding supports that risk of dementia is higher in AF patients than AFL patients. However, the risk of dementia between patients with AF and AFL varies depending on whether there is a previous stroke history.

A new electrophysiological triad for atrial flutter critical isthmus identification and localization

Abstract Funding Acknowledgements Type of funding sources: None. Introduction In a previous retrospective study it was demonstrated that an electrophysiological triad was able to identify critical isthmus in atrial flutter (AFL) patients. This triad is based in the Carto® electroanatomical mapping (EAM) version 7, which displays a histogram of the local activation times (LAT) of the tachycardia cycle length (TCL), in addition to the activation and voltage maps. This study aimed to prospectively assess the ability of an electrophysiological triad to identify and localize the AFL’s critical isthmus. Methods Prospective analysis of a unicentric registry of individuals who underwent left AFL ablation with Carto® EAM. All patients with non-left AFL, lack of high-density EAM, less than 2000 collected points or lack of mapping in any of the left atrium walls or structures were excluded. Ablation sites of arrhythmia termination were compared to an electrophysiological triad constituted by: areas of low-voltage (0.05 to 0.3mV), sites of deep histogram valleys (LAT-Valleys) with less than 20% density points relative to the highest density zone and a prolonged LAT-Valley duration that included 10% or more of the TCL. The longest LAT-Valley was designated as the primary valley, while additional valleys were named as secondary. Results A total of 12 patients (9 men, median age 72 IQR 67-75 years) were included. All patients presented with left AFL and 67% had a previous atrial fibrillation and/or flutter ablation. The median TCL and number collected points were 250 (230─290) milliseconds and 3150 (IQR 2340─3870) points, respectively. All AFL presented with at least 1 LAT-Valley in the analysed histograms, which corresponded to heterogeneous low-voltage areas (0.05 to 0.3mV) and encompassed more than 10% of TCL. Eleven of the 12 patients presented with at least 1 secondary LAT-Valley. All arrhythmias were effectively terminated after undergoing radiofrequency ablation in the primary or the secondary LAT-Valley location. Conclusion In a prospective analysis, an electrophysiological triad was able to identify the AFL critical isthmus in all patients. Further studies are needed to assess the usefulness of this algorithm to improve catheter ablation outcomes.

Head-to-head comparison of proprietary PPG and single-lead ECG algorithms for atrial fibrillation detection

Abstract Funding Acknowledgements Type of funding sources: None. Background Population based screening for atrial fibrillation (AF) has been suggested to reduce stroke. Photoplethysmography (PPG) deriving smartphone apps and single-lead electrocardiography (ECG) tools are attractive devices for screening due to their low cost, convenience, and accessibility. Automated algorithm analysis can serve as pre-screening or remote monitoring for AF, while confirmation on an ECG trace &amp;gt;30s is required to establish the diagnosis. This work directly compares the performance of proprietary algorithms on PPG vs single-lead ECG for the detection of AF. Purpose To evaluate and compare the diagnostic performance of a PPG-deriving smartphone app and a single-lead ECG-deriving handheld device for AF detection. Methods Patients were recruited from the cardiology ward. After obtaining written informed consent, demographic and medical information were collected. Patients were instructed to perform one measurement using a pulse-deriving smartphone app and one via a single-lead ECG handheld device. A 12-lead electrocardiogram (ECG) was collected and interpreted by a cardiologist as gold standard. Patients with atrial flutter were excluded, with additional exclusions for insufficient quality measurements and unsuccessful measurements resulting due to technical errors. Unclassified single-lead ECG measurements were handled as test-negative. Sensitivity, specificity and accuracy were calculated with respect to the reference diagnosis. McNemar’s analysis was performed to compare the sensitivity and specificity of the proprietary PPG and single-lead ECG AF detection algorithms. Results The median age in the study population (n = 300) was 70 years (interquartile range: 51-78), 56.3% were men, and the median CHA2DS2-VASc was 3 (interquartile range: 1-4) with an AF-prevalence of 32.3%. PPG signal and single‑lead ECG quality was sufficient in 272/300 (91.0%) and 278/298 (93.3%) participants, respectively. After excluding atrial flutter patients (n = 25) and insufficient quality measurements, the sensitivity and specificity were 97.6% (95% CI 93.8 to 99.3) and 94.1% (95% CI 86.8 to 98.1) for the PPG signal versus 95.7% (95% CI 91.4 to 98.3) and 91.1% (95% CI 83.2 to 96.1) for the single‑lead ECG signal, respectively. Results demonstrated a 96.4% (95% CI 93.2 to 98.3) accuracy for PPG and 94.1% (95% CI 90.4 to 96.6) for single-lead ECG. No significant differences in sensitivity (P = 0.453) or specificity (P = 0.219) between the proprietary PPG and single-lead ECG algorithms were found. Conclusion This study demonstrated equivalent diagnostic performance of PPG and single-lead ECG proprietary AF detection algorithms in smartphone apps.

Incidence, electrophysiological characteristics, and long-term follow-up of perimitral atrial flutter in patients with previously confirmed mitral isthmus block.

IntroductionAfter mitral isthmus (ΜΙ) catheter ablation, perimitral atrial flutter (PMF) circuits can be maintained due to the preservation of residual myocardial connections, even if conventional pacing criteria for complete MI block are apparently met (MI pseudo‐block). We aimed to study the incidence, the electrophysiological characteristics, and the long‐term outcome of these patients.MethodsSeventy‐two consecutive patients (mean age 62.4 ± 10.2, 62.5% male) underwent MI ablation, either as part of an atrial fibrillation (AF) ablation strategy (n = 35), or to treat clinical reentrant atrial tachycardia (AT) (n = 32), or to treat AT that occurred during ablation for AF (n = 5). Ιn all patients, the electrophysiological characteristics of PMF circuits were studied by high‐density mapping.ResultsMitral isthmus block was successfully achieved in 69/72 patients (95.6%). Five patients developed PMF after confirming MI block. In these patients, high‐density mapping during the PMF showed a breakthrough in MI with extremely low impulse conduction velocity (CV). In contrast, in usual PMF circuits that occurred after AF ablation, the lowest CV of the reentrant circuit was of significantly higher value (0.07 ± 0.02 m/s vs 0.25 ± 0.07 m/s, respectively; P < .001). Patients presented with clinical AT had better prognosis in maintaining sinus rhythm after MI ablation compared with patients presented with AF.ConclusionPerimitral atrial flutter with MI pseudo‐block may be present after MI ablation and has specific electrophysiological features characterized by remarkably slow CV in the MI. Thus, even after MI block is achieved, a more detailed mapping in the boundaries of the ablation line or reinduction attempts may be needed to exclude residual conduction.

Evolution of Antithrombotic Management of Atrial Fibrillation After Percutaneous Coronary Intervention Over 10 Years and Guidelines Uptake

BackgroundThe management of atrial fibrillation and/or flutter (AF) patients requiring percutaneous coronary intervention (PCI) has evolved significantly. The Canadian Cardiovascular Society AF guidelines, last updated in 2020, seek to aid physicians in balancing both bleeding and thrombotic risks. MethodsA tertiary academic centre registry of patients with AF who had PCI was examined for the antithrombotic therapy at discharge in 4 time periods (cohort 2010–2011; cohort 2014–2015; cohort 2017; cohort 2019). Discharge prescription patterns were compared among the cohorts, using the χ2 test. In addition, antithrombotic management in cohorts 2017 and 2019 were compared to guideline-expected therapy, using the χ2 test. ResultsA total of 576 AF patients undergoing PCI were included. Clinical and procedural characteristics were similar among cohorts, except for an increase in drug-eluting stent use in the most recent cohort (94% vs 99%; P = 0.04). The rate of oral anticoagulation increased over time (75% vs 89%; P < 0.01), driven primarily by an increase in direct oral anticoagulants prescription (63% vs 84%; P < 0.01). In contrast to previous cohorts, there was no significant difference between the observed and the guideline-expected anticoagulation rate in cohort 2019 (89% vs 94%; P = 0.23). ConclusionsA combination of expert guidance and educational initiatives in the past decade contributed to dramatic changes in the management of patients with AF undergoing PCI.

Thromboembolic events following cardioversion of acute atrial fibrillation and flutter: a systematic review and meta-analysis.

Recent studies have presented concerning data on the safety of cardioversion for acute atrial fibrillation and flutter. We conducted this meta-analysis to evaluate the effect of oral anticoagulation use on thromboembolic events post-cardioversion of low-risk acute atrial fibrillation and flutter patients of < 48h in duration. We searched MEDLINE, Embase, and Cochrane from inception through February 6, 2020 for studies reporting thromboembolic events post-cardioversion of acute atrial fibrillation and flutter. Main outcome was thromboembolic events within 30days post-cardioversion. Primary analysis compared thromboembolic events based on oral anticoagulation use versus no oral anticoagulation use. Secondary analysis was based on baseline thromboembolic risk. We performed meta-analyses where 2 or more studies were available, by applying the DerSimonian-Laird random-effects model. Risk of bias was assessed with the Quality in Prognostic Studies tool. Of 717 titles screened, 20 studies met inclusion criteria. Primary analysis of seven studies with low risk of bias demonstrated insufficient evidence regarding the risk of thromboembolic events associated with oral anticoagulation use (RR = 0.82 where RR < 1 suggests decreased risk with oral anticoagulation use; 95% CI 0.27 to 2.47; I2 = 0%). Secondary analysis of 13 studies revealed increased risk of thromboembolic events with high baseline thromboembolic risk (RR = 2.25 where RR > 1 indicates increased risk with higher CHADS2 or CHA2DS2-VASc scores; 95% CI 1.25 to 4.04; I2 = 0%). Primary analysis revealed insufficient evidence regarding the effect of oral anticoagulation use on thromboembolic events post-cardioversion of low-risk acute atrial fibrillation and flutter, though the event rate is low in contemporary practice. Our findings can better inform patient-centered decision-making when considering 4-week oral anticoagulation use for acute atrial fibrillation and flutter patients.

Automatic Extraction of Recurrent Patterns of High Dominant Frequency Mapping During Human Persistent Atrial Fibrillation.

Purpose: Identifying targets for catheter ablation remains challenging in persistent atrial fibrillation (persAF). The dominant frequency (DF) of atrial electrograms during atrial fibrillation (AF) is believed to primarily reflect local activation. Highest DF (HDF) might be responsible for the initiation and perpetuation of persAF. However, the spatiotemporal behavior of DF remains not fully understood. Some DFs during persAF were shown to lack spatiotemporal stability, while others exhibit recurrent behavior. We sought to develop a tool to automatically detect recurrent DF patterns in persAF patients.Methods: Non-contact mapping of the left atrium (LA) was performed in 10 patients undergoing persAF HDF ablation. 2,048 virtual electrograms (vEGMs, EnSite Array, Abbott Laboratories, USA) were collected for up to 5 min before and after ablation. Frequency spectrum was estimated using fast Fourier transform and DF was identified as the peak between 4 and 10 Hz and organization index (OI) was calculated. The HDF maps were identified per 4-s window and an automated pattern recognition algorithm was used to find recurring HDF spatial patterns. Dominant patterns (DPs) were defined as the HDF pattern with the highest recurrence.Results: DPs were found in all patients. Patients in atrial flutter after ablation had a single DP over the recorded time period. The time interval (median [IQR]) of DP recurrence for the patients in AF after ablation (7 patients) decreased from 21.1 s [11.8 49.7 s] to 15.7 s [6.5 18.2 s]. The DF inside the DPs presented lower temporal standard deviation (0.18 ± 0.06 Hz vs. 0.29 ± 0.12 Hz, p < 0.05) and higher OI (0.35 ± 0.03 vs. 0.31 ± 0.04, p < 0.05). The atrial regions with the highest proportion of HDF region were the septum and the left upper pulmonary vein.Conclusion: Multiple recurrent spatiotemporal HDF patterns exist during persAF. The proposed method can identify and quantify the spatiotemporal repetition of the HDFs, where the high recurrences of DP may suggest a more organized rhythm. DPs presented a more consistent DF and higher organization compared with non-DPs, suggesting that DF with higher OI might be more likely to recur. Recurring patterns offer a more comprehensive dynamic insight of persAF behavior, and ablation targeting such regions may be beneficial.