A Case of Cardioversion and Management of Atrial Flutter in the Emergency Department.

Atrial flutter is a supraventricular cardiac arrhythmia commonly characterized by two or three rapid atrial contractions for every ventricular contraction and a rapid ventricular rate that can be identified by a sawtooth pattern on an electrocardiogram. Patients often present with symptoms of heart failure and face the risk of atrial thrombus with a potential for systemic embolization. As such, pharmacologic rate and rhythm control, transesophageal echocardiogram, direct current cardioversion, and anticoagulation therapies may all be required for patient management. This case study provides an example of the patient presentation, exam findings, diagnostic results, and intervention modalities required for the health care provider to manage atrial flutter correctly in the emergency department setting.

The burden of atrial fibrillation/flutter in the Middle East and North Africa region and its associated risk factors from 1990 to 2019.

BACKGROUND: Atrial fibrillation and flutter (AFF) are the most common cardiac arrhythmias globally, contributing to substantial morbidity and mortality. The Middle East and North Africa (MENA) region face unique challenges in managing cardiovascular diseases, including AFF, due to diverse sociodemographic factors and healthcare infrastructure variability. This study aims to comprehensively evaluate the burden of AFF in MENA from 1990 to 2019. METHODS: Data were obtained from the Global Burden of Diseases Study 2019, a comprehensive source incorporating diverse data inputs. The study collected global, regional, and national Age-Standardized Incidence Rate (ASIR), Age-Standardized Mortality Rate (ASMR), and Age-Standardized Disability-Adjusted Rate (ASDR), Mortality across sex, age groups, and years. LOESS regression was employed to determine the relationship between age-standardized rates attributed to AFF and Socio-Demographic Index (SDI). RESULTS: The study found minimal change in ASIR of AFF in MENA from 1990 to 2019, with a slight increase observed in ASMR and ASDR during the same period. Notably, AFF burden was consistently higher in females compared to males, with age showing a direct positive relationship with AFF burden. Iraq, Iran, and Turkey exhibited the highest ASIR, while Qatar, Bahrain, and Oman had the highest ASMR and ASDR in 2019. Conversely, Kuwait, Libya, and Turkey displayed the lowest ASMR and ASDR rates. CONCLUSION: This study underscores the persistent burden of AFF in MENA and identifies significant disparities across countries. High systolic blood pressure emerged as a prominent risk factor for mortality in AFF patients. Findings provide crucial insights for policy-making efforts, resource allocation, and intervention strategies aimed at reducing the burden of cardiovascular diseases in the MENA region.

A novel approach to terminate roof-dependent atrial flutter with epicardial conduction through septopulmonary bundle.

Atrial flutter, a prevalent cardiac arrhythmia, is primarily characterized by reentrant circuits in the right atrium. However, atypical forms of atrial flutter present distinct challenges in terms of diagnosis and treatment. In this study, we examine three noteworthy clinical cases of atypical atrial flutter, which offer compelling evidence indicating the implication of the lesser-known Septopulmonary Bundle (SPB). This inference is based on the identification of distinct electrocardiographic patterns observed in these patients and their favorable response to catheter ablation, which is a standard treatment for atrial flutter. Remarkably, in each case, targeted ablation at the anterior portion of the left atrial roof effectively terminated the arrhythmia, thus providing further support for the hypothesis of SPB involvement. These insightful observations shed light on the potential significance of the SPB in the etiology of atypical atrial flutter and introduce a promising therapeutic target. We anticipate that this paper will stimulate further exploration into the role of the SPB in atrial flutter and pave the way for the development of targeted ablation strategies.

External electrical and pharmacological cardioversion for atrial fibrillation, atrial flutter or atrial tachycardias: a network meta-analysis.

BACKGROUND: Atrial fibrillation (AF) is the most frequent sustained arrhythmia. Cardioversion is a rhythm control strategy to restore normal/sinus rhythm, and can be achieved through drugs (pharmacological) or a synchronised electric shock (electrical cardioversion). OBJECTIVES: To assess the efficacy and safety of pharmacological and electrical cardioversion for atrial fibrillation (AF), atrial flutter and atrial tachycardias. SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase, Conference Proceedings Citation Index-Science (CPCI-S) and three trials registers (ClinicalTrials.gov, WHO ICTRP and ISRCTN) on 14 February 2023. SELECTION CRITERIA: We included randomised controlled trials (RCTs) at the individual patient level. Patient populations were aged ≥ 18 years with AF of any type and duration, atrial flutter or other sustained related atrial arrhythmias, not occurring as a result of reversible causes. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methodology to collect data and performed a network meta-analysis using the standard frequentist graph-theoretical approach using the netmeta package in R. We used GRADE to assess the quality of the evidence which we presented in our summary of findings with a judgement on certainty. We calculated differences using risk ratios (RR) and 95% confidence intervals (CI) as well as ranking treatments using a P value. We assessed clinical and statistical heterogeneity and split the networks for the primary outcome and acute procedural success, due to concerns about violating the transitivity assumption. MAIN RESULTS: We included 112 RCTs (139 records), from which we pooled data from 15,968 patients. The average age ranged from 47 to 72 years and the proportion of male patients ranged from 38% to 92%. Seventy-nine trials were considered to be at high risk of bias for at least one domain, 32 had no high risk of bias domains, but had at least one domain classified as uncertain risk, and one study was considered at low risk for all domains. For paroxysmal AF (35 trials), when compared to placebo, anteroapical (AA)/anteroposterior (AP) biphasic truncated exponential waveform (BTE) cardioversion (RR: 2.42; 95% CI 1.65 to 3.56), quinidine (RR: 2.23; 95% CI 1.49 to 3.34), ibutilide (RR: 2.00; 95% CI 1.28 to 3.12), propafenone (RR: 1.98; 95% CI 1.67 to 2.34), amiodarone (RR: 1.69; 95% CI 1.42 to 2.02), sotalol (RR: 1.58; 95% CI 1.08 to 2.31) and procainamide (RR: 1.49; 95% CI 1.13 to 1.97) likely result in a large increase in maintenance of sinus rhythm until hospital discharge or end of study follow-up (certainty of evidence: moderate). The effect size was larger for AA/AP incremental and was progressively smaller for the subsequent interventions. Despite low certainty of evidence, antazoline may result in a large increase (RR: 28.60; 95% CI 1.77 to 461.30) in this outcome. Similarly, low-certainty evidence suggests a large increase in this outcome for flecainide (RR: 2.17; 95% CI 1.68 to 2.79), vernakalant (RR: 2.13; 95% CI 1.52 to 2.99), and magnesium (RR: 1.73; 95% CI 0.79 to 3.79). For persistent AF (26 trials), one network was created for electrical cardioversion and showed that, when compared to AP BTE incremental energy with patches, AP BTE maximum energy with patches (RR 1.35, 95% CI 1.17 to 1.55) likely results in a large increase, and active compression AP BTE incremental energy with patches (RR: 1.14, 95% CI 1.00 to 1.131) likely results in an increase in maintenance of sinus rhythm at hospital discharge or end of study follow-up (certainty of evidence: high). Use of AP BTE incremental with paddles (RR: 1.03, 95% CI 0.98 to 1.09; certainty of evidence: low) may lead to a slight increase, and AP MDS Incremental paddles (RR: 0.95, 95% CI 0.86 to 1.05; certainty of evidence: low) may lead to a slight decrease in efficacy. On the other hand, AP MDS incremental energy using patches (RR: 0.78, 95% CI 0.70 to 0.87), AA RBW incremental energy with patches (RR: 0.76, 95% CI 0.66 to 0.88), AP RBW incremental energy with patches (RR: 0.76, 95% CI 0.68 to 0.86), AA MDS incremental energy with patches (RR: 0.76, 95% CI 0.67 to 0.86) and AA MDS incremental energy with paddles (RR: 0.68, 95% CI 0.53 to 0.83) probably result in a decrease in this outcome when compared to AP BTE incremental energy with patches (certainty of evidence: moderate). The network for pharmacological cardioversion showed that bepridil (RR: 2.29, 95% CI 1.26 to 4.17) and quindine (RR: 1.53, (95% CI 1.01 to 2.32) probably result in a large increase in maintenance of sinus rhythm at hospital discharge or end of study follow-up when compared to amiodarone (certainty of evidence: moderate). Dofetilide (RR: 0.79, 95% CI 0.56 to 1.44), sotalol (RR: 0.89, 95% CI 0.67 to 1.18), propafenone (RR: 0.79, 95% CI 0.50 to 1.25) and pilsicainide (RR: 0.39, 95% CI 0.02 to 7.01) may result in a reduction in this outcome when compared to amiodarone, but the certainty of evidence is low. For atrial flutter (14 trials), a network could be created only for antiarrhythmic drugs. Using placebo as the common comparator, ibutilide (RR: 21.45, 95% CI 4.41 to 104.37), propafenone (RR: 7.15, 95% CI 1.27 to 40.10), dofetilide (RR: 6.43, 95% CI 1.38 to 29.91), and sotalol (RR: 6.39, 95% CI 1.03 to 39.78) probably result in a large increase in the maintenance of sinus rhythm at hospital discharge or end of study follow-up (certainty of evidence: moderate), and procainamide (RR: 4.29, 95% CI 0.63 to 29.03), flecainide (RR 3.57, 95% CI 0.24 to 52.30) and vernakalant (RR: 1.18, 95% CI 0.05 to 27.37) may result in a large increase in maintenance of sinus rhythm at hospital discharge or end of study follow-up (certainty of evidence: low). All tested electrical cardioversion strategies for atrial flutter had very high efficacy (97.9% to 100%). The rate of mortality (14 deaths) and stroke or systemic embolism (3 events) at 30 days was extremely low. Data on quality of life were scarce and of uncertain clinical significance. No information was available regarding heart failure readmissions. Data on duration of hospitalisation was scarce, of low quality, and could not be pooled. AUTHORS' CONCLUSIONS: Despite the low quality of evidence, this systematic review provides important information on electrical and pharmacological strategies to help patients and physicians deal with AF and atrial flutter. In the assessment of the patient comorbidity profile, antiarrhythmic drug onset of action and side effect profile versus the need for a physician with experience in sedation, or anaesthetics support for electrical cardioversion are key aspects when choosing the cardioversion method.

Relationships between adrenal insufficiency and cardiovascular outcomes in patients with atrial fibrillation, atrial flutter and paroxysmal supraventricular tachycardia.

BACKGROUND: Patients with Adrenal Insufficiency (AI) face elevated cardiovascular risks, but little remains known about arrhythmia outcomes in this context. METHOD: Analyzing the 2016-2019 Nationwide Inpatient Sample, we identified cases of Atrial Fibrillation, Atrial Flutter, and paroxysmal supraventricular tachycardia (PSVT) with a secondary diagnosis of AI. Mortality was the primary outcome while vasopressors and/or mechanical ventilation use, length of stay (LOS), and total hospitalization charges (THC) constituted secondary outcomes. Multivariate linear and logistic regression models were used to adjust for confounders. RESULTS: Among patients with Atrial Fibrillation, Atrial Flutter, and PSVT (N=1,556,769), 0.2% had AI. AI was associated with higher mortality (adjusted OR [aOR] 2.29, p=0.001), vasopressor and/or mechanical ventilation use (aOR 2.54, p<0.001), THC ($62,347 vs. $41,627, p<0.001) and longer LOS (4.4 vs. 3.2 days, p<0.001) compared to no AI. CONCLUSION: AI was associated with higher adverse outcomes in cases of Atrial Fibrillation, Atrial Flutter, and PSVT.

Prevalence and Predictors of Readmissions in Patients With Hypertrophic Cardiomyopathy and Atrial Fibrillation/Flutter.

Atrial fibrillation/flutter (AF) is the most common dysrhythmia in patients with hypertrophic cardiomyopathy (HCM). Unexplained left ventricular hypertrophy and left ventricular outflow tract obstruction are integral components of HCM pathology which can cause increased left atrial pressure and atrial myopathy contributing to the substrate for AF. We aimed to determine the impact of AF on hospital readmissions in patients with HCM. We conducted a retrospective analysis using the 2015 to 2019 Nationwide Readmission Database to analyze the effect of AF on 30-day readmission and causes of 30-day readmission in patients with HCM. We also determined the hospital, patient, and procedure-specific independent predictors of readmission in patients with HCM and AF. Of 191,235 index HCM hospitalizations, 81,390 (42.6%) had a secondary diagnosis of AF. A total of 16.9% of patients with HCM and AF were readmitted within 30 days as compared with 14% of HCM patients without AF. The presence of AF was independently associated with a higher risk of all-cause 30-day readmission (hazard ratio [HR] 1.21, 95% confidence interval [CI] 1.17 to 1.25, p <0.001). The foremost etiology of 30-day readmission in HCM patients with AF was hypertensive heart and chronic kidney disease with heart failure, whereas the foremost etiology of 30-day readmission in HCM patients without AF was sepsis. Interventions aimed toward AF management (electrical cardioversion: adjusted HR 0.91, 95% CI 0.82 to 1.01. p = 0.074, AF ablation: HR 0.92, 95% CI 0.74 to 1.13, p = 0.409, Watchman procedure: HR 1.50, 95% CI 0.16 to 14.6, p = 0.725) during index admission did not significantly impact the 30-day readmission in HCM patients with AF. Myectomy during index hospitalization (adjusted HR 0.54, 95% CI 0.34 to 0.86, p = 0.010) was most strongly associated with a lower risk of 30-day readmission in HCM patients with AF. In conclusion, in patients hospitalized for HCM, presence of AF was associated with excess risk of 30-day all-cause readmission. Interventions aimed toward HCM management, that is, myectomy rather than interventions aimed toward AF management predicted lower readmission rate in this patient population.

Optimal timing of electrical cardioversion for acute decompensated heart failure caused by atrial arrhythmias: The earlier, the better?

The optimal timing for electrical cardioversion (ECV) in acute decompensated heart failure (ADHF) with atrial arrhythmias (AAs) is unknown. Here, we retrospectively evaluated the impact of ECV timing on SR maintenance, hospitalization duration, and cardiac function in patients with ADHF and AAs. Between October 2017 and December 2022, ECV was attempted in 73 patients (62 with atrial fibrillation and 11 with atrial flutter). Patients were classified into two groups based on the median number of days from hospitalization to ECV, as follows: early ECV (within 8 days, n = 38) and delayed ECV (9 days or more, n = 35). The primary endpoint was very short-term and short-term ECV failure (unsuccessful cardioversion and AA recurrence during hospitalization and within one month after ECV). Secondary endpoints included (1) acute ECV success, (2) ECVs attempted, (3) periprocedural complications, (4) transthoracic echocardiographic parameter changes within two months following successful ECV, and (5) hospitalization duration. ECV successfully restored SR in 62 of 73 patients (85%), with 10 (14%) requiring multiple ECV attempts (≥ 3), and periprocedural complications occurring in six (8%). Very short-term and short-term ECV failure occurred without between-group differences (51% vs. 63%, P = 0.87 and 61% vs. 72%, P = 0.43, respectively). Among 37 patients who underwent echocardiography before and after ECV success, the left ventricular ejection fraction (LVEF) significantly increased (38% [31-52] to 51% [39-63], P = 0.008) between admission and follow-up. Additionally, hospital stay length was shorter in the early ECV group than in the delayed ECV group (14 days [12-21] vs. 17 days [15-26], P < 0.001). Hospital stay duration was also correlated with days from admission to ECV (Spearman's ρ = 0.47, P < 0.001). In clinical practice, early ECV was associated with a shortened hospitalization duration and significantly increased LVEF in patients with ADHF and AAs.

Atrial flutter complicating acute respiratory distress syndrome (ARDS): A rare case report.

RATIONALE: This case report addresses a unique instance of atrial flutter complicating acute respiratory distress syndrome (ARDS), contributing a novel addition to the medical literature. The co-occurrence of these conditions sheds light on a rare clinical scenario that requires careful consideration. PATIENT CONCERNS: The patient exhibited symptoms of pronounced dyspnea, tachypnea, and hypoxemia. Clinical assessment revealed irregular heart rhythms, notably atrial flutter, alongside characteristic signs of ARDS, including bilateral pulmonary infiltrates and reduced lung compliance. DIAGNOSES AND INTERVENTIONS: After a comprehensive evaluation, the patient was diagnosed with atrial flutter complicating ARDS. Therapeutic measures encompassed antiarrhythmic agents, mechanical ventilation, and targeted ARDS management protocols. The intricate interplay between cardiac and respiratory factors necessitated a multidisciplinary approach. OUTCOMES: Throughout treatment, the patient's respiratory distress gradually improved. Control of the atrial flutter was achieved, and oxygenation levels were restored within acceptable limits. This successful outcome underscores the significance of a well-coordinated treatment strategy in addressing complex cases like this. LESSONS: This case highlights the importance of recognizing and managing the intricate relationship between cardiac arrhythmias such as atrial flutter and respiratory complications like ARDS. The successful management of this patient underscores the value of multidisciplinary collaboration and tailored therapeutic interventions. Practitioners should remain vigilant for such rare complications and consider this case a reminder of the potential complexities that can arise in critical care scenarios.

Cardiovascular Disease: Atrial Fibrillation and Atrial Flutter.

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia in adults, with lifetime rates of 21% to 33%. There are numerous risk factors, including older age, hypertension, coronary disease, obstructive sleep apnea, diabetes, and others. Patients engaging in lifelong high-endurance exercise also have increased risk. Some organizations recommend screening; others do not. However, many patients identify AF themselves using mobile cardiac monitoring devices, some of which accurately detect the arrhythmia. Patients with AF with hemodynamic instability are treated with immediate synchronized cardioversion. Treatment options for stable patients include scheduled cardioversion, rhythm control with pharmacotherapy, catheter ablation, and rate control with pharmacotherapy. Catheter ablation is increasingly used as first-line therapy, with up to 80% of patients remaining AF-free after one or two ablation treatments, an outcome superior to that with pharmacotherapy. Patients with AF should receive anticoagulation based on the CHA2DS2-VASc (Congestive heart failure, Hypertension, Age 75 years or older [doubled], Diabetes, prior Stroke or transient ischemic attack or thromboembolism [doubled], Vascular disease, Age 65 to 74 years, Sex category) score, and also before and immediately after ablation or cardioversion. It is uncertain whether long-term anticoagulation is needed after successful ablation. Atrial flutter (AFL) is the second most common sustained supraventricular arrhythmia. Patients with AFL are at risk of developing AF, and many recommendations for managing AFL are similar to those for AF. The preferred management for AFL is catheter ablation, with success rates exceeding 90%.

Predictors of Transthoracic Impedance in Patients Who Underwent Elective Electrical Cardioversion.

Successful synchronized direct current cardioversion (DCCV) requires adequate current delivery to the heart. However, adequate current for successful DCCV has not yet been established. Transmyocardial current depends on 2 factors: input energy and transthoracic impedance (TTI). Although factors affecting TTI have been studied in animal models, factors affecting TTI in humans have not been well established. Herein, we explored the potential factors that affect TTI in humans. A retrospective review of patients who underwent DCCV at a large quaternary medical center between October 2019 and August 2021 was conducted. Pertinent clinical information, including demographics, echocardiography findings, laboratory findings, and body characteristics, was collected. Cardioversion details, including joules delivered and TTI, were recorded by the defibrillator for each patient's first shock. Predictors of thoracic impedance were assessed using regression analysis. A total of 220 patients (29% women) were included in the analysis; 143 of the patients (65%) underwent DCCV for atrial fibrillation and 77 (35%) underwent DCCV for atrial flutter. The mean impedance in our population was 73 ± 18 Ω. In a regression model with high impedance defined as the upper quartile of our cohort, body mass index (BMI), female sex, obstructive sleep apnea, and chronic kidney disease (all p values <0.05) were significantly associated with high impedance. According to a receiver operating characteristic analysis, BMI has a high predictive value for high impedance, with an area under the curve of 0.76. In conclusion, our study reveals that elevated BMI, female sex, sleep apnea, and chronic kidney disease were predictors of higher TTI. These factors may help determine the appropriate initial shock energy in patients who underwent DCCV for atrial fibrillation and flutter.

Clinical Outcomes of Decompensated Heart Failure With Reduced Ejection Fraction Admissions With or Without Atrial Fibrillation and Atrial Flutter.

The aim of our retrospective study is to determine the influence of co-morbid atrial fibrillation or flutter (AF) on decompensated congestive heart failure (CHF) admissions using data from the 2020 nationwide inpatient sample. We identified 76,835 adults admitted nonelectively with decompensated CHF. After multivariate adjustment, we found decompensated heart failure with reduced ejection fraction (HFrEF) admissions with AF had 37% higher odds of in-hospital mortality, (OR 1.38 [95% CI 1.1-1.72] P < 0.01), 33% higher odds for mechanical ventilation (MV) (OR 1.33 [95% CI 1.14-1.55] P < 0.01), 39% higher odds of early MV (OR 1.39 [95% CI 1.16-1.66] P < 0.01), 54% higher odds of cardiogenic shock (OR 1.54 [95% CI 1.29-1.84] P < 0.01), 61% increased odds of mechanical circulatory support (MCS) requirement (OR 1.61 [95% CI 1.12-2.31] P < 0.02), significantly higher odds of acute renal failure (AKI) necessitating dialysis (OR 2.20 [95% CI 1.39-2.48] P < 0.01), 1-day increase in mean length of stay (LOS) (6.7 vs 5.7 days, adjusted difference: 0.99, P < 0.01), $13,281 increase in total hospitalization charges ($84,316 vs $74,279, adjusted difference: $13,281, P < 0.05) compared to the non-AF cohort. Moreover, we found decompensated heart failure with preserved ejection fraction (HFpEF) admissions with AF had a 23% increased odds of MV (OR 1.23 [95% CI 1.01-1.50] P < 0.01), 24% higher odds of early MV (OR 1.24 [95% CI 1.00-1.53] P < 0.01), 0.36 days increase in mean LOS (5.5 vs 5.2 days, adjusted difference: 0.36, P = < 0.01), but no significant difference in in-hospital mortality (OR 1.23 [95% CI 0.86-1.75] P = 0.25), cardiogenic shock (OR 1.75 [95% CI 0.96-3.19] P < 0.07), dialysis-dependent AKI (OR 0.46 [95% CI 0.18-1.17] P < 0.10), or mean total hospitalization charges ($52,086 vs $47,990, adjusted difference: $5584, P = 0.06) compared to the non-AF cohort.

Clinical characteristics and outcomes of atrial flutter in neonates.

BACKGROUND: Atrial flutter is an uncommon arrhythmia that can cause severe morbidity, including heart failure and even death in refractory cases. This study investigated the clinical characteristics, treatment, and long-term outcomes of patients with neonatal atrial flutter and its association with heart failure. METHODS: We retrospectively reviewed atrial flutter cases observed in our center between 1999 and 2021 and analyzed the clinical characteristics, treatment, and recurrence according to the presence of heart failure. RESULTS: The study comprised 15 patients with atrial flutter, with median bodyweight and gestational age of 2.7 kg, 37+4 weeks, respectively. Twelve patients were diagnosed with atrial flutter on the first day of life. The median atrial and ventricular rates were 440/min, 220/min, respectively. Four patients exhibited congestive heart failure. Episodic recurrence was noted in five patients and occurred at a higher rate in patients with congestive heart failure (p = 0.004). Antiarrhythmic drugs for maintenance treatment were administered more often in patients with heart failure (p = 0.011). Initial treatment included direct current cardioversion (n = 9), digoxin (n = 4), and observation (n = 2). Four patients treated with cardioversion experienced recurrence during the neonatal period, and none of those treated with digoxin experienced recurrence. The median follow-up duration was 7 years, during which no atrial flutter recurrence was evident. CONCLUSION: Neonates with congestive heart failure had a higher recurrence of atrial flutter. Direct current cardioversion is the most reliable treatment for neonatal atrial flutter, whereas digoxin may be a viable treatment option in refractory and recurrent cases.

Transition mechanisms from atrial flutter to atrial fibrillation during anti-tachycardia pacing therapy.

BACKGROUND: Atrial anti-tachycardia pacing (aATP) has been shown to be effective for the termination of atrial tachyarrhythmias, but its success rate is still not high enough. OBJECTIVE: The main objective of this study was to investigate the mechanisms of atrial flutter (AFL) termination by aATP and the transition from AFL to atrial fibrillation (AF) during aATP. METHODS: We developed a multi-scale model of the human atrium based on magnetic resonance images and examined the atrial electrophysiology of AFL during aATP with a ramp protocol. RESULTS: In successful cases of aATP, paced excitation entered the excitable gap and collided with the leading edge of the reentrant wave front. Furthermore, the excitation propagating in the opposite direction collided with the trailing edge of the reentrant wave to terminate AFL. The second collision was made possible by the distribution of the wave propagation velocity in the atria. The detailed analysis revealed that the slowing of propagation velocity occurred at the exit of the sub-Eustachian isthmus, probably due to source-sink mismatch. During the transition from AFL to AF, the excitation collided with the refractory zone of the preceding wave and broke into multiple wave fronts to induce AF. A similar observation was made for the transition from AF to sinus rhythm. In both cases, the complex anatomy of the atria played an essential role. CONCLUSION: The complex anatomy of atria plays an essential role in the maintenance of stable AFL and its termination by aATP, which were revealed by the realistic three-dimensional simulation model.

Right atrial dysfunction is associated with atrial arrhythmias in adults with repaired tetralogy of fallot.

BACKGROUND: Adults with repaired tetralogy of Fallot (TOF) have right atrial (RA) remodeling and dysfunction, and RA function can be measured using speckle tracking echocardiography. There are limited data about the role of RA strain imaging for risk stratification in this population. We hypothesized that RA reservoir strain can identify TOF patients at risk of developing atrial arrhythmia. To test this hypothesis, we assessed the relationship between RA reservoir strain and atrial arrhythmias in adults with repaired TOF. METHOD: Retrospective cohort study of adults with repaired TOF, and no prior history of atrial arrhythmias. Atrial arrhythmia was defined as atrial fibrillation, atrial flutter/atrial tachycardia, and categorized as new-onset versus recurrent atrial arrhythmias. RESULTS: We identified 426 patients (age 33 ± 12 years; males 208 (49%)) that met the inclusion criteria. The mean RA reservoir strain, conduit strain, and booster strain were 34 ± 11%, 20 ± 9%, and 15 ± 12%, respectively. Of 426 patients, 73 (17%) developed new-onset atrial arrhythmias (atrial flutter/tachycardia n = 42; atrial fibrillation n = 31); annual incidence 1.9%. RA reservoir strain was associated with new-onset atrial arrhythmias (adjusted HR 0.95, 95% CI 0.93-0.97) after multivariable adjustment. Of 73 patients with new-onset atrial arrhythmia, 41 (56%) had recurrent atrial arrhythmia (atrial flutter/tachycardia n = 18; atrial fibrillation n = 23); annual incidence 11.2%. Similarly, RA reservoir strain was associated with recurrent atrial arrhythmias (adjusted HR 0.92, 95% CI 0.88-0.96) after multivariable adjustment. CONCLUSIONS: RA strain indices can identify patients at risk for atrial arrhythmias, and this can in turn, be used to guide the type/intensity of therapy in such patients.

Pathophysiology and treatment of adults with arrhythmias in the emergency department, part 1: Atrial arrhythmias.

PURPOSE: This article, the first in a 2-part review, aims to reinforce current literature on the pathophysiology of cardiac arrhythmias and various evidence-based treatment approaches and clinical considerations in the acute care setting. Part 1 of this series focuses on atrial arrhythmias. SUMMARY: Arrhythmias are prevalent throughout the world and a common presenting condition in the emergency department (ED) setting. Atrial fibrillation (AF) is the most common arrhythmia worldwide and expected to increase in prevalence. Treatment approaches have evolved over time with advances in catheter-directed ablation. Based on historic trials, heart rate control has been the long-standing accepted outpatient treatment modality for AF, but the use of antiarrhythmics is often still indicated for AF in the acute setting, and ED pharmacists should be prepared and poised to help in AF management. Other atrial arrhythmias include atrial flutter (AFL), atrioventricular nodal reentry tachycardia (AVNRT), and atrioventricular reentrant tachycardia (AVRT), which warrant distinction due to their unique pathophysiology and because each requires a different approach to utilization of antiarrhythmics. Atrial arrhythmias are typically associated with greater hemodynamic stability than ventricular arrhythmias but still require nuanced management according to patient subset and risk factors. Since antiarrhythmics can also be proarrhythmic, they may destabilize the patient due to adverse effects, many of which are the focus of black-box label warnings that can be overreaching and limit treatment options. Electrical cardioversion for atrial arrhythmias is generally successful and, depending on the setting and/or hemodynamics, often indicated. CONCLUSION: Atrial arrhythmias arise from a variety of mechanisms, and appropriate treatment depends on various factors. A firm understanding of physiological and pharmacological concepts serves as a foundation for exploring evidence supporting agents, indications, and adverse effects in order to provide appropriate care for patients.

Clinical decision support to Optimize Care of patients with Atrial Fibrillation or flutter in the Emergency department: protocol of a stepped-wedge cluster randomized pragmatic trial (O'CAFÉ trial).

BACKGROUND: Management of adults with atrial fibrillation (AF) or atrial flutter in the emergency department (ED) includes rate reduction, cardioversion, and stroke prevention. Different approaches to these components of care may lead to variation in frequency of hospitalization and stroke prevention actions, with significant implications for patient experience, cost of care, and risk of complications. Standardization using evidence-based recommendations could reduce variation in management, preventable hospitalizations, and stroke risk. METHODS: We describe the rationale for our ED-based AF treatment recommendations. We also describe the development of an electronic clinical decision support system (CDSS) to deliver these recommendations to emergency physicians at the point of care. We implemented the CDSS at three pilot sites to assess feasibility and solicit user feedback. We will evaluate the impact of the CDSS on hospitalization and stroke prevention actions using a stepped-wedge cluster randomized pragmatic clinical trial across 13 community EDs in Northern California. DISCUSSION: We hypothesize that the CDSS intervention will reduce hospitalization of adults with isolated AF or atrial flutter presenting to the ED and increase anticoagulation prescription in eligible patients at the time of ED discharge and within 30 days. If our hypotheses are confirmed, the treatment protocol and CDSS could be recommended to other EDs to improve management of adults with AF or atrial flutter. TRIAL REGISTRATION: ClinicalTrials.gov NCT05009225 .  Registered on 17 August 2021.

Diagnosis and management of patients who present with narrow complex tachycardia in the emergency department.

INTRODUCTION: While narrow complex tachycardia (NCT) is a common presentation to the emergency department (ED), little is known about its incidence in the ED or about emergency physician expertise in its diagnosis and management. We sought to compare cases of NCT due to primary arrhythmias to those with a rapid heart rate secondary to a medical issue, as well as to determine the accuracy of ED physician diagnosis and appropriateness of treatment. METHODS: We conducted a health records review at a large academic hospital ED staffed by 95 physicians and included consecutive adult patients over 7 months (2020-2021) with NCT (heart rate ≥ 130 bpm and QRS < 120 ms). Cases were reviewed for accuracy of ECG diagnosis and for correctness of treatment as per guidelines by an adjudication committee. RESULTS: We identified 310 ED visits (0.8% of all ED visits), mean age 65.1 years, 52.6% female. Primary arrhythmias accounted for 54.8%. ED physicians correctly interpreted 86.6% of ECGs. The most common arrhythmias and accuracy of ED physician ECG interpretation were atrial fibrillation 44.5% (95.1%), sinus tachycardia 24.2% (90.5%), atrial flutter 15.8% (61.5%), and supraventricular tachycardia (SVT) 12.9% (81.6%). Treatments were judged optimal in 96.5% of primary NCT and 99.3% in secondary NCT. Treatments were suboptimal for failure to reduce heart rate < 100 bpm prior to discharge in 2.1% of primary cases and failure to treat underlying cause in 0.7% of secondary cases. CONCLUSION: NCT was found in 0.8% of all ED visits, with more being primary NCT. ED physicians correctly interpreted 86.6% of ECGs but had difficulty differentiating atrial flutter and SVT. They implemented appropriate care in most cases but sometimes failed to adequately control heart rate or to treat the underlying condition, suggesting opportunities to improve care of NCT in the ED.

RéSUMé: INTRODUCTION: Bien que la tachycardie à complexe QRS étroite (narrow complex tachycardia [NCT]) soit une présentation courante au service des urgences (SU), on sait peu de choses sur son incidence dans le SU ou sur l'expertise des médecins urgentistes dans son diagnostic et sa prise en charge. Nous avons cherché à comparer les cas de NCT dus à des arythmies primaires à ceux avec une fréquence cardiaque rapide secondaire à un problème médical, ainsi que pour déterminer l'exactitude du diagnostic de médecin ED et la pertinence du traitement. MéTHODES: Nous avons effectué un examen des dossiers médicaux dans les urgences d'un grand hôpital universitaire où travaillent 95 médecins et avons inclus des patients adultes consécutifs sur 7 mois (2020-2021) présentant une NCT (fréquence cardiaque ≥ 130 bpm et QRS < 120 ms). Les cas ont été examinés par un comité d'adjudication pour vérifier l'exactitude du diagnostic ECG et la justesse du traitement conformément aux directives. RéSULTATS: Nous avons recensé 310 visites aux urgences (0,8 % de toutes les visites aux urgences), l'âge moyen étant de 65,1 ans, 52,6 % de femmes. Les arythmies primaires représentaient 54,8 %. Les médecins urgentistes ont correctement interprété 86,6 % des ECG. Les arythmies les plus fréquentes et la précision de l'interprétation de l'ECG par le médecin de l'urgence étaient la fibrillation auriculaire 44,5 % (95,1 %), la tachycardie sinusale 24,2 % (90,5 %), le flutter auriculaire 15,8 % (61,5 %) et la tachycardie supraventriculaire (TSV) 12,9 % (81,6 %). Les traitements ont été jugés optimaux dans 96,5 % des NCT primaires et 99,3 % des NCT secondaires. Les traitements étaient sous-optimaux en raison de l'incapacité à réduire la fréquence cardiaque < 100 bpm avant la sortie de l'hôpital dans 2,1 % des cas primaires et de l'incapacité à traiter la cause sous-jacente dans 0,7 % des cas secondaires. CONCLUSION: Une NCT a été constatée dans 0,8 % de toutes les visites aux urgences, la plupart étant des NCT primaires. Les médecins des services d'urgence ont interprété correctement 86,6 % des ECG mais ont eu des difficultés à différencier le flutter auriculaire et la TSV. Ils ont mis en œuvre des soins appropriés dans la plupart des cas, mais n'ont parfois pas réussi à contrôler adéquatement la fréquence cardiaque ou à traiter l'affection sous-jacente, ce qui laisse entrevoir des possibilités d'améliorer la prise en charge des NCT aux urgences.

Atrial flutter and fibrillation in patients with pulmonary arterial hypertension or chronic thromboembolic pulmonary hypertension in the ASPIRE registry: Comparison of rate versus rhythm control approaches.

BACKGROUND: The development of atrial flutter and fibrillation (AFL/AF) in patients with pre-capillary pulmonary hypertension has been associated with an increased risk of morbidity and mortality. Rate and rhythm control strategies have not been directly compared. METHODS: Eighty-four patients with pulmonary arterial hypertension (PAH) or chronic thromboembolic pulmonary hypertension (CTEPH) with new-onset AFL/AF were identified in the ASPIRE registry. First, baseline characteristics and rates of sinus rhythm (SR) restoration of 3 arrhythmia management strategies (rate control, medical rhythm control and DC cardioversion, DCCV) in an early (2009-13) and later (2014-19) cohort were compared. Longer-term outcomes in patients who achieved SR versus those who did not were then explored. RESULTS: Sixty (71%) patients had AFL and 24 (29%) AF. Eighteen (22%) patients underwent rate control, 22 (26%) medical rhythm control and 44 (52%) DCCV. SR was restored in 33% treated by rate control, 59% medical rhythm control and 95% DCCV (p < 0.001). Restoration of SR was associated with greater improvement in functional class (FC) and Incremental Shuttle Walk Distance (p both <0.05). It also independently predicted superior survival (3-year survival 62% vs 23% in those remaining in AFL/AF, p < 0.0001). In addition, FC III/IV independently predicted higher mortality (HR 2.86, p = 0.007). Right atrial area independently predicted AFL/AF recurrence (OR 1.08, p = 0.01). DCCV was generally well tolerated with no immediate major complications. CONCLUSIONS: Restoration of SR is associated with superior functional improvement and survival in PAH/CTEPH compared with rate control. DCCV is generally safe and is more effective than medical therapy at achieving SR.