Severity of Left Ventricular Dysfunction in Patients With Tachycardia-Induced Cardiomyopathy: Impacts on Remodeling After Atrial Flutter Ablation

Tachycardia-induced cardiomyopathy is defined as a reversible left ventricular (LV) systolic dysfunction (SeD) resulting from a sustained fast heart rate. LV remodeling in patients with severe LV dysfunction at diagnosis remains poorly understood. In this retrospective cohort study, we described LV remodeling in 50 patients who underwent atrial flutter ablation. These patients were divided into severe LV SeD (LV ejection fraction [EF] ≤30%) and LV nonsevere SeD (LVEF 31% to 50%) at baseline. All continuous variables are expressed as median and interquartile range. LVEF was 18% (13 to 25) and 38% (34 to 41) in the SeD (n = 29) and LV nonsevere SeD (n = 21) groups, respectively. At baseline, patients with SeD had higher LV end-diastolic diameter (56 [54 to 59] vs 49 mm [47 to 52], p <0.01), LV end-systolic diameter (48 [43 to 51] vs 36 mm [34 to 41], p <0.01), LV end-diastolic volume (71 [64 to 85] vs 56 ml/m2 [46 to 68], p <0.01), LV end-systolic volume (56 [53 to 70] vs 36 ml/m2 [27 to 42], p <0.01), and lower tricuspid annular plane systolic excursion (12 [10 to 13] vs 16 mm [13 to 19], p <0.01). At last follow-up, LVEF was not statistically significantly different between groups. However, LV end-systolic diameter (36 [34 to 39] vs 32 mm [32 to 34], p = 0.01) and LV end-systolic volume (29 [26 to 35] vs 25 ml/m2 [20 to 29], p = 0.02) remained larger in the SeD group. Seven patients (14%), all from the SeD group, had a LVEF ≤35% 2 months after rhythm control, and reverse remodeling was observed up to 9 months. In conclusion, more than half of patients with tachycardia-induced cardiomyopathy and atrial flutter had LVEF ≤30% at baseline. LVEF recovery and LV remodeling were observed beyond 2 months, highlighting the importance of rhythm control and early guideline-directed medical therapy in these patients.

Risk of atrial arrhythmias in patients with ventricular tachycardia in arrhythmogenic right ventricular cardiomyopathy

BACKGROUND

In arrhythmogenic right ventricular cardiomyopathy (ARVC), risk of atrial arrhythmias (AAs) persists after ventricular tachycardia (VT) ablation.

OBJECTIVE

The purpose of this study was to determine the type, prevalence, outcome, and risk correlates of AA in ARVC in patients undergoing VT ablation.

METHODS

Prospectively collected procedural and clinical data on ARVC patients undergoing VT ablation were analyzed. Risk score for typical atrial flutter was determined from univariate logistic regression analysis.

RESULTS

Of 119 consecutive patients with ARVC and VT ablation, 40 (34%) had AA: atrial fibrillation (AF) in 31, typical isthmus-dependent atrial flutter (AFL) in 27, and atrial tachycardia/atypical flutter (AT) in 10. Seventeen patients (43%) with AA experienced inappropriate defibrillator therapy, with 15 patients experiencing shocks. Ablation was performed for typical AFL in 21 (53%), AT in 5 (13%), and pulmonary vein isolation for AF in 4 (10%) patients and prevented AA in 78% and all AFL during additional mean follow-up of 65 months. Risk score for typical flutter included age >40 years (1 point), ≥moderate right ventricular dysfunction (2 points), ≥moderate tricuspid regurgitation (2 points), ≥moderate right atrial dilation (2 points), and right ventricular volume >250 cc (3points), with score >4 identifying 50% prevalence of typical flutter.

CONCLUSION

AAs are common in patients with ARVC and VT, can result in inappropriate implantable cardioverter-defibrillator shocks, and typically are controlled with atrial ablation. A risk score can be used to identify patients at high risk for typical AFL who may be considered for isthmus ablation at the time of VT ablation.

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.

Acute cardiac tamponade during atrial flutter ablation: improved hemodynamics after positive pressure ventilation: a case report

INTRODUCTION

Acute cardiac tamponade is a rare event during any type of interventional or surgical procedure. It can occur during electrophysiology procedures due to radiofrequency ablation, lead or catheter manipulation, transseptal puncture, laser lead extractions, or left atrial appendage occlusion device positioning. Cardiac tamponade is difficult to study in a prospective manner, and case reports and case series are important contributions to understanding the best options for patient care. An 87-year-old Caucasian male patient breathing spontaneously developed acute tamponade during an atrial flutter ablation. Pericardial drain insertion was difficult, and hypotension failed to respond to epinephrine boluses. The patient became hypoxemic and hypercarbic, requiring intubation. Unexpectedly, the blood pressure markedly increased postintubation and remained in a normal range until the pericardium was drained.

CONCLUSION

Spontaneous ventilation is considered important to maintain venous return to the right heart during cardiac tamponade. However, spontaneous ventilation reduces venous return to the left heart and worsens the paradoxical pulse in tamponade. Intravenous vasopressors are thought to be ineffective during cardiac tamponade. Our patient maintained pulmonary blood flow as indicated by end-tidal carbon dioxide measurements but had no measurable systemic blood pressure during spontaneous ventilation. Our case demonstrates that tracheal intubation and positive pressure ventilation can transiently improve left heart venous return, systemic perfusion, and drug delivery to the systemic circulation.

Intrauterine management and outcomes of persistent fetal atrial flutter: A case report

BACKGROUND

Fetal atrial flutter (AF), accounting for 30% of all fetal tachyarrhythmias, predominantly (over 80%) manifests as a 2:1 atrioventricular conduction. Swift referral and timely intervention become imperative in instances of severe persistent arrhythmia.

CASE PRESENTATION

We discuss the case of a 32-year-old multiparous Chinese woman, at 30+2 weeks of gestation, wherein an ultrasonographic examination revealed persistent fetal AF (atrial rate ranging from 219 to 445 beats/min and ventricular rate from 219 to 228 beats/min, with a 2:1 or 1:1 down transmission) and minor ascites. Despite the maternal ingestion of digoxin and sotalol, the fetal heart rhythm remained uncorrected. Following this, at 32+3 weeks of gestation, an intramuscular injection of cedilanid, guided by ultrasound, was administered to the fetus. Postoperatively, the fetal ventricular rate demonstrated a decline after 6 days, and the ascites resolved. Subsequently, at 33+3 weeks, a cesarean section was necessitated due to maternal intolerance to the medication, resulting in the delivery of the infant. Remarkably, the infant's cardiac rhythm spontaneously converted to sinus rhythm within 5 min of birth. A follow-up conducted 1 year postpartum revealed no recurrence of AF.

CONCLUSIONS

This case illustrates that in the event of transplacental drug treatment failure, intrauterine therapeutic intervention should be considered. Moreover, it highlights the encouraging prognosis associated with fetal AF, as the cardiac rhythm spontaneously reverted to sinus rhythm postbirth in this instance.

Implementation of an integrated emergency department acute atrial fibrillation pathway safely reduces cardioversions and hospitalisations: A comparative pre-post study

OBJECTIVE

Atrial fibrillation/flutter (AF/AFL) accounts for high rates of ED presentations and hospital admissions. There is increasing evidence to suggest that delaying cardioversion for acute uncomplicated AF is safe, and that many patients will spontaneously revert to sinus rhythm (SR). We conducted a before-and-after evaluation of AF/AFL management after a change in ED pathway using a conservative 'rate-and-wait' approach, incorporating next working day outpatient clinic follow-up and delayed cardioversion if required.

METHODS

We performed a before-and-after retrospective cohort study examining outcomes for patients who presented to the ED in Christchurch, New Zealand, with acute uncomplicated AF/AFL in the 1-year period before and after the implementation of a new conservative management pathway.

RESULTS

A total of 360 patients were included in the study (182 'Pre-pathway' vs 178 'Post-Pathway'). Compared to the pre-pathway cohort, those managed under the new pathway had an 81.2% reduction in ED cardioversions (n = 32 vs n = 6), and 50.7% reduction in all cardioversions (n = 65 vs n = 32). There was a 31.6% reduction in admissions from ED (n = 54 vs n = 79). ED length of stay (3.9 h vs 3.8 h, net difference -0.1 h, 95% confidence interval [CI] -0.6 to 0.3), 1-year ED AF representation (32.4% vs 26.4%, net difference -6.0% [95% CI -16.0% to 3.9%]), 1-year ED ischaemic stroke presentation (2.2% in both groups) and 7-day all-cause mortality rates (hazard ratio 1.05 [95% CI 0.6 to 1.9]) were all similar.

CONCLUSIONS

Using a conservative 'rate-and-wait' strategy with early follow-up for patients presenting to ED with AF/AFL can safely reduce unnecessary cardioversions and avoidable hospitalisations.

Iodine-Induced Hyperthyroidism and Long-term Risks of Incident Atrial Fibrillation and Flutter

CONTEXT

Although iodine-induced hyperthyroidism is a potential consequence of iodinated radiologic contrast administration, its association with long-term cardiovascular outcomes has not been previously studied.

OBJECTIVE

To investigate the relationships between hyperthyroidism observed after iodine contrast administration and incident atrial fibrillation/flutter.

METHODS

Retrospective cohort study of the U.S. Veterans Health Administration (1998-2021) of patients age ≥18 years with a normal baseline serum thyrotropin (TSH) concentration, subsequent TSH <1 year, and receipt of iodine contrast <60 days before the subsequent TSH. Cox proportional hazards regression was employed to ascertain the adjusted hazard ratio (HR) with 95% CI of incident atrial fibrillation/flutter following iodine-induced hyperthyroidism, compared with iodine-induced euthyroidism.

RESULTS

Iodine-induced hyperthyroidism was observed in 2500 (5.6%) of 44 607 Veterans (mean ± SD age, 60.9 ± 14.1 years; 88% men) and atrial fibrillation/flutter in 10.4% over a median follow-up of 3.7 years (interquartile range 1.9-7.4). Adjusted for sociodemographic and cardiovascular risk factors, iodine-induced hyperthyroidism was associated with an increased risk of atrial fibrillation/flutter compared with those who remained euthyroid after iodine exposure (adjusted HR 1.19, 95% CI 1.06-1.33). Females were at greater risk for incident atrial fibrillation/flutter than males (females, HR 1.81, 95% CI 1.12-2.92; males, HR 1.15, 95% CI 1.03-1.30; P for interaction = .04).

CONCLUSION

Hyperthyroidism following a high iodine load was associated with an increased risk of incident atrial fibrillation/flutter, particularly among females. The observed sex-based differences should be confirmed in a more sex-diverse study sample, and the cost-benefit analysis of long-term monitoring for cardiac arrhythmias following iodine-induced hyperthyroidism should be evaluated.

Predicting stroke and mortality in mitral stenosis with atrial flutter: A machine learning approach

BACKGROUND

Our study hypothesized that an intelligent gradient boosting machine (GBM) model can predict cerebrovascular events and all-cause mortality in mitral stenosis (MS) with atrial flutter (AFL) by recognizing comorbidities, electrocardiographic and echocardiographic parameters.

METHODS

The machine learning model was used as a statistical analyzer in recognizing the key risk factors and high-risk features with either outcome of cerebrovascular events or mortality.

RESULTS

A total of 2184 patients with their chart data and imaging studies were included and the GBM analysis demonstrated mitral valve area (MVA), right ventricular systolic pressure, pulmonary artery pressure (PAP), left ventricular ejection fraction (LVEF), New York Heart Association (NYHA) class, and surgery as the most significant predictors of transient ischemic attack (TIA/stroke). MVA, PAP, LVEF, creatinine, hemoglobin, and diastolic blood pressure were predictors for all-cause mortality.

CONCLUSION

The GBM model assimilates clinical data from all diagnostic modalities and significantly improves risk prediction performance and identification of key variables for the outcome of MS with AFL.

Brady- and tachyarrhythmias detected by continuous rhythm monitoring in paroxysmal atrial fibrillation

OBJECTIVE

Atrial fibrillation (AF) is associated with adverse events including conduction disturbances, ventricular arrhythmias and sudden death. The aim of this study was to examine brady- and tachyarrhythmias using continuous rhythm monitoring in patients with paroxysmal self-terminating AF (PAF).

METHODS

In this multicentre observational substudy to the Reappraisal of Atrial Fibrillation: interaction between hyperCoagulability, Electrical remodelling and Vascular destabilisation in the progression of AF (RACE V), we included 392 patients with PAF and at least 2 years of continuous rhythm monitoring. All patients received an implantable loop recorder, and all detected episodes of tachycardia ≥182 beats per minute (BPM), bradycardia ≤30 BPM or pauses ≥5 s were adjudicated by three physicians.

RESULTS

Over 1272 patient-years of continuous rhythm monitoring, we adjudicated 1940 episodes in 175 patients (45%): 106 (27%) patients experienced rapid AF or atrial flutter (AFL), pauses ≥5 s or bradycardias ≤30 BPM occurred in 47 (12%) patients and in 22 (6%) patients, we observed both episode types. No sustained ventricular tachycardias occurred. In the multivariable analysis, age >70 years (HR 2.3, 95% CI 1.4 to 3.9), longer PR interval (HR 1.9, 1.1-3.1), CHA2DS2-VASc score ≥2 (HR 2.2, 1.1-4.5) and treatment with verapamil or diltiazem (HR 0.4, 0.2-1.0) were significantly associated with bradyarrhythmia episodes. Age >70 years was associated with lower rates of tachyarrhythmias.

CONCLUSIONS

In a cohort exclusive to patients with PAF, almost half experienced severe bradyarrhythmias or AF/AFL with rapid ventricular rates. Our data highlight a higher than anticipated bradyarrhythmia risk in PAF.

TRIAL REGISTRATION NUMBER

NCT02726698.

Ability of the DANCAMI to predict the risk ischemic stroke and mortality in patients with atrial fibrillation/flutter

OBJECTIVES

Comparison of the danish comorbidity index for acute myocardial infarction (DANCAMI), the charlson comorbidity index (CCI), the elixhauser comorbidity index (ECI), and the CHA2DS2-VASc score to predict ischemic stroke, cardiovascular mortality, and all-cause mortality after atrial fibrillation/flutter.

MATERIALS AND METHODS

A population-based cohort study of all Danish patients with incident atrial fibrillation/flutter during 2000-2020 (n=361,901). C-Statistics were used to evaluate the discriminatory performance for predicting 1 and 5-year risks of the outcomes for a baseline model (including age and sex) +/- the individual indices.

RESULTS

For the DANCAMI, the 5-year risk did not increase with comorbidity burden for ischemic stroke (5.9% for low vs. 5.6% for severe) but did increase for cardiovascular mortality (10% for low vs. 16% for severe) and all-cause mortality (33% for low vs. 61% for severe). C-Statistics for predicting 5-year ischemic stroke risk were similar for all models (0.64). C-Statistics for predicting 5-year cardiovascular mortality risk were also similar for the baseline (0.76), the DANCAMI (0.77), the CCI (0.76), the ECI (0.76), and the CHA2DS2-VASc (0.76) models. C-Statistics for predicting 5-year all-cause mortality risk were lower for the baseline (0.71) and the CHA2DS2-VASc (0.71) models than for the DANCAMI (0.75), the CCI (0.74), and the ECI (0.74) models. The 1-year C-Statistics were comparable.

CONCLUSION

The DANCAMI predicted ischemic stroke and cardiovascular mortality risks similar to the CCI, the ECI, and the CHA2DS2-VASc. The DANCAMI predicted all-cause mortality risk similar to the CCI and the ECI, but better than the baseline and the CHA2DS2-VASc.

Interatrial Block Association With Adverse Cardiovascular Outcomes in Patients Without a History of Atrial Fibrillation

BACKGROUND

Interatrial block (IAB) is associated with thromboembolism and atrial arrhythmias. However, prior studies included small patient cohorts so it remains unclear whether IAB predicts adverse outcomes particularly in context of atrial fibrillation (AF)/atrial flutter (AFL).

OBJECTIVES

This study sought to determine whether IAB portends increased stroke risk in a large cohort in the presence or absence of AFAF/AFL.

METHODS

We performed a 5-center retrospective analysis of 4,837,989 electrocardiograms (ECGs) from 1,228,291 patients. IAB was defined as P-wave duration ≥120 ms in leads II, III, or aVF. Measurements were extracted as .XML files. After excluding patients with prior AF/AFL, 1,825,958 ECGs from 458,994 patients remained. Outcomes were analyzed using restricted mean survival time analysis and restricted mean time lost.

RESULTS

There were 86,317 patients with IAB and 355,032 patients without IAB. IAB prevalence in the cohort was 19.6% and was most common in Black (26.1%), White (20.9%), and Hispanic (18.5%) patients and least prevalent in Native Americans (9.2%). IAB was independently associated with increased stroke probability (restricted mean time lost ratio coefficient [RMTLRC]: 1.43; 95% CI: 1.35-1.51; tau = 1,895), mortality (RMTLRC: 1.14; 95% CI: 1.07-1.21; tau = 1,924), heart failure (RMTLRC: 1.94; 95% CI: 1.83-2.04; tau = 1,921), systemic thromboembolism (RMTLRC: 1.62; 95% CI: 1.53-1.71; tau = 1,897), and incident AF/AFL (RMTLRC: 1.16; 95% CI: 1.10-1.22; tau = 1,888). IAB was not associated with stroke in patients with pre-existing AF/AFL.

CONCLUSIONS

IAB is independently associated with stroke in patients with no history of AF/AFL even after adjustment for incident AF/AFL and CHA2DS2-VASc score. Patients are at increased risk of stroke even when AF/AFL is not identified.

Association between sodium-glucose cotransporter-2 inhibitors and incident atrial fibrillation/atrial flutter in heart failure patients with reduced ejection fraction: a meta-analysis of randomized controlled trials

Atrial fibrillation (AF) and atrial flutter (AFL) are associated with adverse outcomes in patients with heart failure and reduced ejection fraction (HFrEF). We investigated the effects of sodium-glucose cotransporter-2 inhibitors (SGLT2i) on the incidence of AF and/or AFL in HFrEF patients. PubMed and ClinicalTrials.gov were systematically searched until March 2022 for randomized controlled trials (RCTs) that enrolled patients with HFrEF. A total of six RCTs with 9467 patients were included (N = 4731 in the SGLT2i arms; N = 4736 in the placebo arms). Compared to placebo, SGLT2i treatment was associated with a significant reduction in the risk of AF [relative risk (RR) 0.62, 95% confidence interval CI 0.44-0.86; P = 0.005] and AF/AFL (RR 0.64, 95% CI 0.47-0.87; P = 0.004). Subgroup analysis showed that empagliflozin use resulted in a significant reduction in the risk of AF (RR 0.55, 95% CI 0.34-0.89; P = 0.01) and AF/AFL (RR 0.50, 95% CI 0.32-0.77; P = 0.002). By contrast, dapagliflozin use was not associated with a significant reduction in the risk of AF (RR 0.69, 95% CI 0.43-1.11; P = 0.12) or AF/AFL (RR 0.82, 95% CI 0.53-1.27; P = 0.38). Additionally, a "shorter" duration (< 1.5 years) of treatment with SGLT2i remained associated with a reduction in the risk of AF (< 1.5 years; RR 0.58, 95% CI 0.36-0.91; P = 0.02) and AF/AFL (< 1.5 years; RR 0.52, 95% CI 0.34-0.80; P = 0.003). In conclusion, SGLT2i therapy was associated with a significant reduction in the risk of AF and AF/AFL in patients with HFrEF. These results reinforce the value of using SGLT2i in this setting.

Impact of Pulmonary Hypertension Hemodynamic Phenotype on Incident Atrial Fibrillation

INTRODUCTION

Atrial fibrillation/flutter (AF) is common among patients with pulmonary hypertension (PH) and is associated with poor clinical outcomes. AF has been shown to occur more commonly among patients with postcapillary PH, although AF also occurs among patients with precapillary PH. The goal of this study was to evaluate the independent impact of PH hemodynamic phenotype on incident AF among patients with PH.

METHODS

We retrospectively identified 262 consecutive patients, without a prior diagnosis of atrial arrhythmias, seen at the PH clinic at Mayo Clinic, Florida, between 1997 and 2017, who had right heart catheterization and echocardiography performed, with follow-up for outcomes through 2021. Kaplan-Meier analysis and Cox-proportional hazards regression modeling were used to evaluate the independent effect of PH hemodynamic phenotype on incident AF.

RESULTS

Our study population was classified into two broad PH hemodynamic groups: precapillary (64.9%) and postcapillary (35.1%). The median age was 59.5 years (Q1: 48.4, Q3: 68.4), and 72% were female. In crude models, postcapillary PH was significantly associated with incident AF (HR 2.17, 95% CI: 1.26-3.74, p = 0.005). This association was lost following multivariable adjustment, whereas left atrial volume index remained independently associated with incident AF (aHR 1.30, 95% CI: 1.09-1.54, p = 0.003).

CONCLUSION

We found PH hemodynamic phenotype was not significantly associated with incident AF in our patient sample; however, echocardiographic evidence of left atrial remodeling appeared to have a greater impact on AF development. Larger studies are needed to validate these findings and identify potential modifiable risk factors for AF in this population.

Latest incidence and electrocardiographic predictors of atrial fibrillation: a prospective study from China

BACKGROUND

China bears the biggest atrial fibrillation (AF) burden in the world. However, little is known about the incidence and predictors of AF. This study aimed to investigate the current incidence of AF and its electrocardiographic (ECG) predictors in general community individuals aged over 60 years in China.

METHODS

This was a prospective cohort study, recruiting subjects who were aged over 60 years and underwent annual health checkups from April to July 2015 in four community health centers in Songjiang District, Shanghai, China. The subjects were then followed up from 2015 to 2019 annually. Data on sociodemographic characteristics, medical history, and the resting 12-lead ECG were collected. Kaplan-Meier curve was used for showing the trends in AF incidence and calculating the predictors of AF. Associations of ECG abnormalities and AF incidence were examined using Cox proportional hazard models.

RESULTS

This study recruited 18,738 subjects, and 351 (1.87%) developed AF. The overall incidence rate of AF was 5.2/1000 person-years during an observation period of 67,704 person-years. Multivariable Cox regression analysis indicated age (hazard ratio [HR], 1.07; 95% confidence interval [CI]: 1.06-1.09; P < 0.001), male (HR, 1.30; 95% CI: 1.05-1.62; P = 0.018), a history of hypertension (HR, 1.55; 95% CI: 1.23-1.95; P < 0.001), a history of cardiac diseases (HR, 3.23; 95% CI: 2.34-4.45; P < 0.001), atrial premature complex (APC) (HR, 2.82; 95% CI: 2.17-3.68; P < 0.001), atrial flutter (HR, 18.68; 95% CI: 7.37-47.31; P < 0.001), junctional premature complex (JPC) (HR, 3.57; 95% CI: 1.59-8.02; P = 0.002), junctional rhythm (HR, 18.24; 95% CI: 5.83-57.07; P < 0.001), ventricular premature complex (VPC) (HR, 1.76; 95% CI: 1.13-2.75, P = 0.012), short PR interval (HR, 5.49; 95% CI: 1.36-22.19; P = 0.017), right atrial enlargement (HR, 6.22; 95% CI: 1.54-25.14; P = 0.010), and pacing rhythm (HR, 3.99; 95% CI: 1.57-10.14; P = 0.004) were independently associated with the incidence of AF.

CONCLUSIONS

The present incidence of AF was 5.2/1000 person-years in the studied population aged over 60 years in China. Among various ECG abnormalities, only APC, atrial flutter, JPC, junctional rhythm, short PR interval, VPC, right atrial enlargement, and pacing rhythm were independently associated with AF incidence.

Association of Intravenous Potassium and Magnesium Administration With Spontaneous Conversion of Atrial Fibrillation and Atrial Flutter in the Emergency Department

IMPORTANCE

Whether the simultaneous intravenous administration of potassium and magnesium is associated with the probability of spontaneous conversion to sinus rhythm (SCV) in the acute treatment of atrial fibrillation (AF) and atrial flutter (AFL) is unknown.

OBJECTIVE

To assess potassium and magnesium administration and SCV probability in AF and AFL in the emergency department.

DESIGN, SETTING, AND PARTICIPANTS

A registry-based cohort study was conducted in the Department of Emergency Medicine of the Medical University of Vienna, Austria. All consecutive patients with AF or AFL were screened between February 6, 2009, and February 16, 2020.

INTERVENTIONS

Intravenous administration of potassium, 24 mEq, and magnesium, 145.8 mg.

MAIN OUTCOMES AND MEASURES

The primary outcome was the probability of SCV during the patient's stay in the emergency department. Multivariable cluster-adjusted logistic regression was used to estimate the association between potassium and magnesium administration and the probability of SCV.

RESULTS

A total of 2546 episodes of nonpermanent AF (median patient age, 68 [IQR, 58-75] years, 1411 [55.4%] men) and 573 episodes of nonpermanent AFL (median patient age, 68 [IQR, 58-75] years; 332 [57.9%] men) were observed. In AF episodes, intravenous potassium and magnesium administration vs no administration was associated with increased odds of SCV (19.2% vs 10.4%; odds ratio [OR], 1.98; 95% CI, 1.53-2.57). In AFL episodes, in contrast, no association was noted for the probability of SCV with potassium and magnesium vs no administration (13.0% vs 12.5%; OR, 1.05; 95% CI, 0.65-1.69).

CONCLUSIONS AND RELEVANCE

The findings of this registry-based cohort study on intravenous administration of potassium and magnesium suggest an increased probability of SCV in nonpermanent AF, but not AFL, during a patients' stay in the emergency department.

Canagliflozin and atrial fibrillation in type 2 diabetes mellitus: A secondary analysis from the CANVAS Program and CREDENCE trial and meta-analysis

AIM

To assess the effects of canagliflozin on the incidence of atrial fibrillation/atrial flutter (AF/AFL) and other key cardiorenal outcomes in a pooled analysis of the CANVAS and CREDENCE trials.

MATERIALS AND METHODS

Participants with type 2 diabetes and high risk of cardiovascular disease or chronic kidney disease were included and randomly assigned to canagliflozin or placebo. We explored the effects of canagliflozin on the incidence of first AF/AFL events and AF/AFL-related complications (ischaemic stroke/transient ischaemic attack/hospitalization for heart failure). Major adverse cardiovascular events and a renal-specific outcome by baseline AF/AFL status were analysed using Cox regression models.

RESULTS

Overall, 354 participants experienced a first AF/AFL event. Canagliflozin had no detectable effect on AF/AFL (hazard ratio [HR] 0.82, 95% confidence interval [CI] 0.67-1.02) compared with placebo. Subgroup analysis, however, suggested a possible reduction in AF/AFL in those with no AF/AFL history (HR 0.78, 95% CI 0.62-0.99). Canagliflozin was also associated with a reduction in AF/AFL-related complications (HR 0.74, 95% CI 0.65-0.86). There was no evidence of treatment heterogeneity by baseline AF/AFL history for other key cardiorenal outcomes (all P_interaction  > 0.14). Meta-analysis of five sodium-glucose cotransporter-2 (SGLT2) inhibitor trials demonstrated a 19% reduction in AF/AFL events with active treatment (HR 0.81, 95% CI 0.72-0.92).

CONCLUSIONS

Overall, a significant effect of canagliflozin on the incidence of AF/AFL events could not be shown, however, a possible reduction in AF/AFL events in those with no prior history requires further investigation. Meta-analysis suggests SGLT2 inhibition reduces AF/AFL incidence.

Increased Body Mass Index and Risk of Left Atrial Thrombus in Nonvalvular Atrial Fibrillation Patients-Data from the Left Atrial Thrombus on Transesophageal Echocardiography (LATTEE) Registry

An increased body mass index (BMI) is associated with a higher incidence of atrial fibrillation (AF) and a higher risk of thromboembolic complications in AF patients. The aim of this study was to investigate the effect of BMI on the risk of left atrial thrombi (LATs) in patients with nonvalvular AF/atrial flutter (AFl) (NV AF/AFl). Patients diagnosed with NVAF/AFl (between November 2018 and May 2020) were selected from the multicenter, prospective, observational Left Atrial Thrombus on Transesophageal Echocardiography (LATTEE) registry that included AF/AFl patients referred for cardioversion or ablation followed by transesophageal echocardiography. A total of 2816 AF/AFl patients (63.6% males; mean age 65.8 years; mean BMI 29.8 kg/m2) were included in the study. Two hundred and twenty-two of them (7.9%) had LATs. Compared with normal-weight patients, those with BMIs ≥ 25 kg/m2 more frequently presented clinical factors potentially provoking LATs, such as non-paroxysmal AF/AFl (p = 0.04), hypertension (p < 0.001), and diabetes (p < 0.001); had higher CHA2DS2 scores (p < 0.001); and had larger LA dimensions (LA diameter and LA area) (p < 0.001 for both parameters). On the other hand, they showed some features negatively related to thromboembolic risk; for example, they were younger (p < 0.001) and were more often male (p = 0.002). In addition, patients with abnormal BMIs were more likely to be smokers (p = 0.006) and to be treated with oral anticoagulants (p = 0.005). Despite these differences in the prevalence of thromboembolic risk factors, the incidence of LATs was not increased in patients with abnormal body weight (overweight and obese compared to normal-weight patients) in this large real-life cohort of AF/AFl patients. This is probably due to the balanced composition regarding the prevalence of positive and negative thromboembolic risk factors.

An Unfortunate Combination of Tachycardia and Myocardial Bridge: A Case of Myocardial Infarction Related to Atrial Flutter

Tachyarrhythmias can lead to chest discomfort, which is usually not severe. However, some patients do complain of severe angina and show evidence of ischemia. As our case study demonstrates, one of the possible mechanisms in these situations is tachyarrhythmia in the presence of an underlying myocardial bridge, resulting in myocardial ischemia due to persistent arterial compression.

Effect of Implantable vs Prolonged External Electrocardiographic Monitoring on Atrial Fibrillation Detection in Patients With Ischemic Stroke: The PER DIEM Randomized Clinical Trial

IMPORTANCE

The relative rates of detection of atrial fibrillation (AF) or atrial flutter from evaluating patients with prolonged electrocardiographic monitoring with an external loop recorder or implantable loop recorder after an ischemic stroke are unknown.

OBJECTIVE

To determine, in patients with a recent ischemic stroke, whether 12 months of implantable loop recorder monitoring detects more occurrences of AF compared with conventional external loop recorder monitoring for 30 days.

DESIGN, SETTING, AND PARTICIPANTS

Investigator-initiated, open-label, randomized clinical trial conducted at 2 university hospitals and 1 community hospital in Alberta, Canada, including 300 patients within 6 months of ischemic stroke and without known AF from May 2015 through November 2017; final follow-up was in December 2018.

INTERVENTIONS

Participants were randomly assigned 1:1 to prolonged electrocardiographic monitoring with either an implantable loop recorder (n = 150) or an external loop recorder (n = 150) with follow-up visits at 30 days, 6 months, and 12 months.

MAIN OUTCOMES AND MEASURES

The primary outcome was the development of definite AF or highly probable AF (adjudicated new AF lasting ≥2 minutes within 12 months of randomization). There were 8 prespecified secondary outcomes including time to event analysis of new AF, recurrent ischemic stroke, intracerebral hemorrhage, death, and device-related serious adverse events within 12 months.

RESULTS

Among the 300 patients who were randomized (median age, 64.1 years [interquartile range, 56.1 to 73.7 years]; 121 were women [40.3%]; and 66.3% had a stroke of undetermined etiology with a median CHA2DS2-VASc [congestive heart failure, hypertension, age ≥75 years, diabetes, stroke or transient ischemic attack, vascular disease, age 65 to 74 years, sex category] score of 4 [interquartile range, 3 to 5]), 273 (91.0%) completed cardiac monitoring lasting 24 hours or longer and 259 (86.3%) completed both the assigned monitoring and 12-month follow-up visit. The primary outcome was observed in 15.3% (23/150) of patients in the implantable loop recorder group and 4.7% (7/150) of patients in the external loop recorder group (between-group difference, 10.7% [95% CI, 4.0% to 17.3%]; risk ratio, 3.29 [95% CI, 1.45 to 7.42]; P = .003). Of the 8 specified secondary outcomes, 6 were not significantly different. There were 5 patients (3.3%) in the implantable loop recorder group who had recurrent ischemic stroke vs 8 patients (5.3%) in the external loop recorder group (between-group difference, -2.0% [95% CI, -6.6% to 2.6%]), 1 (0.7%) vs 1 (0.7%), respectively, who had intracerebral hemorrhage (between-group difference, 0% [95% CI, -1.8% to 1.8%]), 3 (2.0%) vs 3 (2.0%) who died (between-group difference, 0% [95% CI, -3.2% to 3.2%]), and 1 (0.7%) vs 0 (0%) who had device-related serious adverse events.

CONCLUSIONS AND RELEVANCE

Among patients with ischemic stroke and no prior evidence of AF, implantable electrocardiographic monitoring for 12 months, compared with prolonged external monitoring for 30 days, resulted in a significantly greater proportion of patients with AF detected over 12 months. Further research is needed to compare clinical outcomes associated with these monitoring strategies and relative cost-effectiveness.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02428140.

A randomized clinical trial to evaluate the efficacy and safety of rivaroxaban in patients with bioprosthetic mitral valve and atrial fibrillation or flutter: Rationale and design of the RIVER trial

The efficacy and safety of rivaroxaban in patients with bioprosthetic mitral valves and atrial fibrillation or flutter remain uncertain. DESIGN: RIVER was an academic-led, multicenter, open-label, randomized, non-inferiority trial with blinded outcome adjudication that enrolled 1005 patients from 49 sites in Brazil. Patients with a bioprosthetic mitral valve and atrial fibrillation or flutter were randomly assigned (1:1) to rivaroxaban 20 mg once daily (15 mg in those with creatinine clearance <50 mL/min) or dose-adjusted warfarin (target international normalized ratio 2.0-30.); the follow-up period was 12 months. The primary outcome was a composite of all-cause mortality, stroke, transient ischemic attack, major bleeding, valve thrombosis, systemic embolism, or hospitalization for heart failure. Secondary outcomes included individual components of the primary composite outcome, bleeding events, and venous thromboembolism. SUMMARY: RIVER represents the largest trial specifically designed to assess the efficacy and safety of a direct oral anticoagulant in patients with bioprosthetic mitral valves and atrial fibrillation or flutter. The results of this trial can inform clinical practice and international guidelines.

Temporal Trends in Population Rates of Incident Atrial Fibrillation and Atrial Flutter Hospitalizations, Stroke Risk, and Mortality Show Decline in Hospitalizations

BACKGROUND

Hospitalization for nonvalvular atrial fibrillation (NVAF) is common and results in substantial cost burden. Current national data trends for the incidence, stroke risk profiles, and mortality of hospitalization for NVAF and atrial flutter (AFL) are sparse.

METHODS

The Canadian Institute of Health Information Discharge Abstract Database was used to identify patients ≥ 20 years with incident NVAF/AFL (NVAF, ICD-9 code 427.3 or ICD-10 I48) in any diagnosis field from 2006 to 2015 in Canada, except Québec. National and provincial trends in rate over time (rate ratio, 95% confidence interval [CI]) were calculated for age-sex standardized hospitalizations. Trends in stroke risk profiles and in-hospital mortality rates adjusted for stroke risk factors were also calculated.

RESULTS

A total of 578,947 patients were hospitalized with incident NVAF/AFL. The median age was 77 years (interquartile range: 68-84), 82% were ≥ 65 years, 54% were men, 54% had a CHADS2 ≥ 2, and 69% had a CHA2DS2-Vasc ≥ 3. The overall age- and sex-standardized rate of NVAF/AFL hospitalization was 315 per 100,000 population and declined by 2% per year (P < 0.001). There was an annual rate decline in NVAF/AFL hospitalizations in every province. The majority of hospitalized patients are at high risk of stroke, and this risk remained unchanged. The average adjusted in-hospital mortality was 8.80 per 100 patients 95% CI, 8.80-8.81 with a 2% annual decline in rate (P < 0.001).

CONCLUSION

Between 2006 and 2015, we found national and provincial hospitalization rates for incident NVAF/AFL are declining. The majority of patients are at high risk for stroke. In-hospital mortality has declined but remains substantial.

The Effect of Positive Airway Pressure Treatment of Obstructive and Central Sleep Apnea on the Recurrence of Atrial Fibrillation/Flutter Postintervention

STUDY OBJECTIVES

A strong association between sleep-disordered breathing (SDB) and atrial fibrillation and/or atrial flutter (AF) has consistently been observed in epidemiologic and interventional studies. The effect of positive airway pressure (PAP) on AF recurrence is inconclusive. This study sought to evaluate the effectiveness of PAP therapy for SDB on AF recurrence.

METHODS

This was a single-center, retrospective study conducted at a tertiary referral center. All adult patients who had SDB on polysomnography and underwent AF intervention (ablation or cardioversion) following polysomnography from January 1992-December 2014 were analyzed. Primary outcome was time to first-documented recurrence of AF after AF intervention by Kaplan-Meier estimates.

RESULTS

Among 30,188 patients with obstructive and central SDB, 429 had this diagnosis before AF intervention; 269 were "PAP-adherent users," the remaining 160 were "PAP-nonusers." Patients in both groups had similar age, sex, body mass index (BMI), ejection fraction, left atrial volume index (LAVI), antiarrhythmic medications, diabetes mellitus, systemic hypertension, and heart failure diagnoses. Time to recurrence of AF postintervention was no different in PAP-adherent users and nonusers (4.8 and 4.1 months respectively, P = .7). Cardioversion (compared to catheter ablation) was the strongest independent predictor of recurrent AF (hazard ratio [HR] 2.02, 95% confidence interval [CI] 1.39-2.94, P < .001). BMI and LAVI were also significant predictors of recurrence in adjusted analyses (HR 1.01, 95% CI 1.003-1.023, P = .10 and HR 1.01, 95% CI 1.001-1.019, P = .024 respectively).

CONCLUSIONS

Our study found no effect of PAP treatment of SDB on time to recurrence of AF post-AF intervention. Increased risk of recurrent AF was associated with high BMI and LAVI. These findings may affect the clinical management of AF.

Comparison of incidence of acute kidney injury, chronic kidney disease and end-stage renal disease between atrial fibrillation and atrial flutter: real-world evidences from a propensity score-matched national cohort analysis

We investigated the adverse renal outcomes in patients affected by either atrial fibrillation (Afib) or atrial flutter (AFL). Using the Taiwan National Health Insurance research database, both cohorts were 1:1 propensity score matched based on age, sex, index year, and comorbidity using logistic regression model. Hazard ratios (HRs) and corresponding 95% confidence intervals (CIs) of acute kidney injury (AKI), chronic kidney disease (CKD), and end-stage renal disease (ESRD) between the two cohorts were obtained using Cox proportional hazard regression models. Competing-risks regression models were applied to calculate the subhazard ratios (SHRs) and corresponding 95% CIs of the adverse renal outcomes. Afib patients were 1.15 and 1.33 times more likely to experience CKD and ESRD, respectively, than AFL patients (incidence rate per 10,000 person-years (IR): CKD, 10.8 vs 9.41; ESRD, 4.44 vs 3.34), with the adjusted HRs of 1.18 and 1.32 (CKD, 95% CI = 1.07-1.30; ESRD, 95% CI = 1.12-1.55). Afib patients were 1.08 times (95% CI = 1.01-1.16) more likely to have AKI than AFL patients after adjusting for confounding covariates. Competing risk analysis showed that Afib patients were 1.08 (95% CI = 1.01-1.15), 1.18 (95% CI = 1.07-1.30) and 1.32 (95% CI = 1.12-1.55) times more likely to experience AKI, CKD and ESRD than AFL subjects. This study showed that Afib conferred worse renal events of AKI, CKD and ESRD than AFL.

Detection of Atrial Fibrillation and Atrial Flutter by Pacemaker Device Interrogation After Transcatheter Aortic Valve Replacement (TAVR): Implications for Management

BACKGROUND

Atrial fibrillation (AF) and atrial flutter (AFL) are associated with increased risk of stroke and mortality after transcatheter aortic valve replacement (TAVR). Many episodes of new-onset AF/AFL (NOAF) occur after hospital discharge and may not be clinically apparent. Pacemakers can detect subclinical episodes of rapid atrial rate, which correlate with electrocardiographically documented AF.

METHODS

From 2012 to 2017, patients who underwent pacemaker implantation after TAVR were reviewed, and pacemaker data from device checks were analyzed for detection of NOAF. Patients with prior AF/AFL were excluded. Secondary outcomes were mortality and ischemic stroke.

RESULTS

A total of 172 patients underwent TAVR and pacemaker implantation, and 95 were without pre-existent AF/AFL. Over a median follow-up of 15 months, a total of 24 patients had NOAF (25%), of which 10 patients (10.5%) had manifest NOAF detected on electrocardiography, and 14 patients (14.7%) had subclinical NOAF first identified on device interrogation. The cumulative incidence of mortality was 16.7% for NOAF and 15.5% for normal sinus rhythm (P=.83). The cumulative incidence of stroke was 12.5% for NOAF and 1.4% for normal sinus rhythm (P=.04). Subclinical NOAF patients were less likely to be started on anticoagulation compared with manifest NOAF patients (70% vs 15.3%, respectively; P=.02).

CONCLUSION

Subclinical NOAF is common after TAVR, usually occurs months after hospital discharge, and is associated with lack of anticoagulation therapy and increased risk of stroke. Prolonged surveillance of subclinical NOAF may be warranted after TAVR.

Is von Willebrand factor associated with stroke and death at mid-term in patients with non-valvular atrial fibrillation?

BACKGROUND

Heart failure and atrial fibrillation share common mechanisms that may contribute to hypercoagulability and thrombotic risk. Elevated von Willebrand factor (vWF) concentration has been associated with increased risk of thromboembolism and cardiovascular events.

AIM

To investigate whether increased vWF plasma concentration predicts occurrence of a composite endpoint (all-cause death and stroke) in patients with non-valvular atrial fibrillation (NVAF).

METHODS

We prospectively studied 122 patients (mean age 70±14years; 46% men) hospitalized with NVAF, and followed over a median (interquartile range) of 5.4 (2.3-9.0)years. Cox proportional models were used to estimate the association of vWF concentration with time to stroke and death.

RESULTS

Forty-three patients (35%) had at least a stroke or died during the 5-year follow-up. Kaplan-Meier curves using vWF plasma concentration tertiles (≤191IU/dL;>191 to≤295IU/dL;>295IU/dL) showed that vWF plasma concentrations discriminated groups of patients with higher cardiovascular event rates (log-rank P=0.01). In the multivariable analysis, higher vWF concentrations (middle tertile hazard ratio [HR] 4.59, 95% confidence interval [CI] 1.55-13.50 [P=0.006]; upper tertile HR 4.10, 95% CI 1.43-11.75 [P=0.009]), age≥75years (HR 5.02, 95% CI 1.53-16.49; P=0.008), heart failure (HR 2.05, 1.01-4.19; P=0.048), C-reactive protein, log₂ per unit increase (HR 1.29, 95% CI 1.04-1.61; P=0.021), no warfarin at discharge (HR 4.96, 95% CI 2.02-12.20; P<0.0001) and no aspirin at discharge (HR 4.41, 95% CI 1.71-11.97; P=0.002) were independently associated with an increased risk of stroke and all-cause death, whereas female sex was a protective factor (HR 0.35, 0.16-0.78; P=0.01).

CONCLUSIONS

High vWF plasma concentrations may discriminate patients with NVAF at greater risk of stroke or all-cause death.

Comparison of Clinical Outcomes Among Patients With Atrial Fibrillation or Atrial Flutter Stratified by CHA2DS2-VASc Score

IMPORTANCE

Current guidelines support treating atrial fibrillation (AF) and atrial flutter (AFL) as equivalent risk factors for ischemic stroke stratified by CHA2DS2-VASc scores, recommending anticoagulation therapy for patients with a CHA2DS2-VASc score of 2 or higher, but some studies found differences in clinical outcomes.

OBJECTIVE

To investigate differences in clinical outcomes among AF, AFL, and matched control cohorts.

DESIGN, SETTING, AND PARTICIPANTS

This nationwide cohort study analyzed data from the Taiwan National Health Insurance Research Database from January 1, 2001, through December 31, 2012. Follow-up and data analysis ended December 31, 2012. A total of 219 416 age- and sex-matched individuals participated in the study. Clinical outcomes were compared after stratification by CHA2DS2-VASc score (possible score range, 0-9; higher scores indicate greater risk of ischemic stroke).

MAIN OUTCOMES AND MEASURES

Ischemic stroke, heart failure hospitalization, and all-cause mortality among the AF, AFL, and matched control cohorts were analyzed using Cox proportional hazards regression.

RESULTS

This study comprised 188 811 patients in the AF cohort (mean [SD] age, 73.8 [13.4] years; 104 703 [55.5%] male), 6121 patients in the AFL cohort (mean [SD] age, 67.7 [15.8] years; 3735 [61.0%] male), and 24 484 patients in the matched control cohort (mean [SD] age, 67.3 [15.6] years; 14 940 [61.0%] male). The patients with AF were older, were more predominantly female, and had higher CHA2DS2-VASc scores than the patients with AFL and the control participants. After stratification by CHA2DS2-VASc score, the incidence densities (IDs; events per 100 person-years) of ischemic stroke (AF cohort: ID, 3.08; 95% CI, 3.03-3.13; AFL cohort: ID, 1.45; 95% CI, 1.28-1.62; controls: ID, 0.97; 95% CI, 0.92-1.03), heart failure hospitalization (AF cohort: ID, 3.39; 95% CI, 3.34-3.44; AFL cohort: ID, 1.57; 95% CI, 1.39-1.74; controls: ID, 0.32; 95% CI, 0.29-0.35), and all-cause mortality (AF cohort: ID, 17.8; 95% CI, 17.7-17.9; AFL cohort: ID, 13.9; 95% CI, 13.4-14.4; controls: ID, 4.2; 95% CI, 4.1-4.4) were significantly higher in the AF cohort than in the matched control cohort. For the AFL cohort vs the matched control cohort, the incidences of heart failure hospitalization and all-cause mortality were significantly higher across all levels, but the incidence of ischemic stroke was only significantly higher at CHA2DS2-VASc scores of 5 to 9. For the AF cohort vs the AFL cohort, the incidences of ischemic stroke and heart failure hospitalization were significantly higher at a CHA2DS2-VASc score of 1 or higher, but the incidence of all-cause mortality was significantly higher only at CHA2DS2-VASc scores of 1 to 3.

CONCLUSIONS AND RELEVANCE

This study found different clinical outcomes between patients with AFL and AF and those without AF and AFL. The current recommended level of the CHA2DS2-VASc score in preventing ischemic stroke in patients with AFL should be reevaluated.

Usefulness of the external loop recorder in a patient with Myotonic Dystrophy type 1 and recurrent episodes of palpitations: evaluation of the follow-up from diagnosis to 6 month-post-cardiac interventional treatment

A patient with Myotonic Dystrophy type 1 and recurrent episodes of palpitations is reported, in which the application of an external loop recorder (ELR) was useful for the diagnosis and post radiofrequency ablation follow-up of typical atrial flutter.

Atrial Appendage Thrombosis Risk Is Lower for Atrial Flutter Compared with Atrial Fibrillation

BACKGROUND

The risk of stroke and thromboembolism in atrial fibrillation is established. However, the evidence surrounding the risk of thromboembolism in patients with atrial flutter is not as clear. We hypothesized that atrial flutter would have indicators of less risk for thromboembolism compared with atrial fibrillation on transesophageal echocardiography, thereby possibly leading to a lower stroke risk.

METHODS

A retrospective review of 2225 patients undergoing transesophageal echocardiography was performed. Those with atrial fibrillation or atrial flutter were screened. Exclusion criteria were patients being treated with chronic anticoagulation, the presence of a prosthetic valve, moderate to severe mitral regurgitation or stenosis, congenital heart disease, or a history of heart transplantation. A total of 114 patients with atrial fibrillation and 55 patients with atrial flutter met the criteria and were included in the analysis.

RESULTS

Twelve patients (11%) in the atrial fibrillation group had left atrial appendage thrombus versus zero patients in the atrial flutter group (P < .05). The prevalence of spontaneous echocardiography contrast was significantly higher and left atrial appendage emptying velocity was significantly lower in the atrial fibrillation group compared with the atrial flutter group (P < .001). No spontaneous contrast was seen when the left atrial appendage emptying velocity was >60 cm/sec.

CONCLUSIONS

Patients with atrial flutter have a lower incidence of left atrial appendage thrombi, higher left atrial appendage emptying velocity, and less left atrial spontaneous contrast compared with patients with atrial fibrillation, suggesting a lower risk for potential arterial thromboembolism.

Predictors of Acute Failure Ablation of Intra-atrial Re-entrant Tachycardia in Patients With Congenital Heart Disease: Cardiac Disease, Atypical Flutter, and Previous Atrial Fibrillation

BACKGROUND

Intra-atrial re-entrant tachycardia (IART) in patients with congenital heart disease (CHD) increases morbidity and mortality. Radiofrequency catheter ablation has evolved as the first-line treatment. The aim of this study was to analyze the acute success and to identify predictors of failed IART radiofrequency catheter ablation in CHD.

METHODS AND RESULTS

The observational study included all consecutive patients with CHD who underwent a first ablation procedure for IART at a single center from January 2009 to December 2015 (94 patients, 39.4% female, age: 36.55±14.9 years). In the first procedure, 114 IART were ablated (acute success: 74.6%; 1.21±0.41 IART per patient) with an acute success of 74.5%. Cavotricuspid isthmus-related IART was the only arrhythmia in 51%; non-cavotricuspid isthmus-related IART was the only mechanism in 27.7% and 21.3% of the patients had both types of IART. Predictors of acute radiofrequency catheter ablation failure were as follows: nonrelated cavotricuspid isthmus IART (odds ratio 7.3; confidence interval [CI], 1.9-17.9; P=0.04), previous atrial fibrillation (odds ratio 6.1; CI, 1.3-18.4; P=0.02), transposition of great arteries (odds ratio, 4.9; CI, 1.4-17.2; P=0.01) and systemic ventricle dilation (odds ratio 4.8; CI, 1.1-21.7; P=0.04) with an area under the receiver operating characteristic curve of 0.83±0.056 (CI, 0.74-0.93, P=0.001). After a mean follow-up longer than 3.5 years, 78.3% of the patients were in sinus rhythm (33.1% of the patients required more than 1 radiofrequency catheter ablation procedure).

CONCLUSIONS

Although ablation in CHD is a challenging procedure, acute success of 75% can be achieved in moderate-highly complex CHD patients in a referral center. Predictors of failed ablation are IART different from cavotricuspid isthmus, previous atrial fibrillation, and markers of complex CHD (transposition of great arteries, systemic ventricle dilation).

Arrhythmia Surgery for Adults with Congenital Heart Disease

Patients with repaired or unrepaired congenital heart anomalies are at increased risk for arrhythmia development throughout their lives, often paralleling the need for reoperations for hemodynamic residua. The ability to incorporate arrhythmia surgery into reoperations can result in improvement in functional class and decreased need for antiarrhythmic medications. Every reoperation for congenital heart disease can be viewed as an opportunity to assess the electrical and arrhythmia substrates and to intervene to improve the arrhythmias and the hemodynamic condition of the patient. The authors review and summarize the operative techniques for arrhythmia surgery that are based on the arrhythmia mechanisms.

Outcomes of Direct Current Cardioversion in Adults With Congenital Heart Disease

Few data exist on direct current cardioversion (DCCV) in adult patients with congenital heart disease (CHD). This is a retrospective case-control study of 279 adults with CHD and 279 adults without CHD (control group) who had elective DCCV for atrial arrhythmias at Mayo Clinic, 2001 to 2013. Control patients were matched by gender and arrhythmia type. The objective was to compare DCCV procedural failure (failure to terminate the presenting arrhythmia) and arrhythmia recurrence (AR). In the CHD group (mean age 55 ± 20 years; men 166 [59%]), the most common diagnosis was Fontan palliation (61; 22%). Transesophageal echocardiography was performed before DCCV in 216 patients (77%); 162 (58%) had atrial flutter, and 117 (42%) had atrial fibrillation. Procedural failure and AR between the case and the control groups were more common in the CHD group (14% vs 7%, p = 0.01) and (83% vs 66% at 60 months, p = 0.001) respectively. There were no deaths or thromboembolic complications. The multivariable risk factors for procedural failure were Fontan palliation and spontaneous echocardiographic contrast; the risk factors for AR were Fontan palliation and atrial fibrillation. When patients with Fontan palliation were excluded from the analysis, the outcome of DCCV (failure and recurrence rates) was similar for the CHD and non-CHD groups despite the age difference between the cohorts. In conclusion, the present study showed that DCCV outcomes were similar for CHD and non-CHD patients, with the exception of patients with Fontan palliation.

[Digoxin poisoning: new prospects for therapy]

The filter has been approved by the Food and Drug Administration for the removal of beta-2 microglobulin in patient undergoing hemodialysis. We used the filter (the patient agrees) off label, in the course of digitalis intoxication and we have shown that the filter is capable of removing the drug effectively.

Influence of atrial fibrillation on post-discharge natriuretic peptide trajectory and clinical outcomes among patients hospitalized for heart failure: insights from the ASTRONAUT trial

AIMS

Change in NT-proBNP level is a common surrogate endpoint in early phase heart failure (HF) trials, but whether this endpoint is influenced by atrial fibrillation/flutter (AFF) is unclear.

METHODS AND RESULTS

This analysis included 1358 patients from the ASTRONAUT trial, which randomized patients hospitalized for HF with EF ≤40% to aliskiren or placebo in addition to standard care. Patients were stratified by presence of AFF on baseline ECG. NT-proBNP was measured longitudinally by a core laboratory at baseline, 1 month, 6 months, and 12 months. Compared with non-AFF patients, AFF patients experienced greater reduction from baseline in log-transformed NT-proBNP (interaction P < 0.001), but this difference was not significant after adjustment (interaction P = 0.726). The ability of aliskiren to lower NT-proBNP during follow-up differed by AFF status (interaction P = 0.001), with aliskiren lowering NT-proBNP more than placebo among non-AFF patients only. After adjustment, baseline AFF was not associated with mortality or HF hospitalization at 12 months (all P ≥ 0.152).

CONCLUSION

In this hospitalized HF cohort, AFF status did not influence post-discharge NT-proBNP trajectory or clinical outcomes after adjustment for patient characteristics. Aliskiren lowered follow-up NT-proBNP levels in patients without AFF, but had no influence among patients with AFF. This study generates the hypothesis that the ability of a HF trial to meet an NT-proBNP defined endpoint may be influenced by the prevalence of AFF in the population. Because aliskiren did not improve outcomes in patients without AFF, this analysis suggests changes in NT-proBNP induced by investigational therapies may be dissociated from clinical effects.

Do Different Atrial Flutter Types Carry the Same Thromboembolic Risk?

Thromboembolic risk of atrial flutter (AFl) types has not been elucidated sufficiently in previous reports. The authors classified the patients according to surface electrocardiogram and electrophysiologic characteristics as those with typical AFl (37 patients, 78.4% male, mean age 59.8 ±9.5 years) and atypical AFl (13 patients, 69.2% male, mean age 60.9 ±6.9 years) and compared them regarding some clinical, echocardiographic, and hematologic parameters. An age- and gender-matched control group composed of 20 individuals without any organic heart disease in sinus rhythm was chosen (80% male, mean age 60.3 ±7.9 years). Clinical features such as age, gender, organic heart disease, hypertension, diabetes mellitus, AFl duration, and the prevalence of paroxysmal atrial fibrillation were similar in both AFl groups. Echocardiographic parameters such as left ventricular ejection fraction, left atrial (LA) diameter, LA spontaneous echo contrast, and LA appendage emptying velocities were similar in both AFl groups. Fibrinogen, fibrin D-dimer, and thrombin-antithrombin III levels reflecting coagulation system activity were found to be increased in the patients with atypical AFl when compared with those with typical AFl and the control group (p<0.001). In Pearson’s correlation analysis, significant correlation between these hematologic markers and clinical and echocardiographic parameters were not found (p>0.05). The coagulation system activity was found to be increased in patients with atypical AFl. Thus, anticoagulation due to the increased thromboembolic risk should be considered in patients with atypical AFl.

Prediction of vascular dementia and Alzheimer's disease in patients with atrial fibrillation or atrial flutter using CHADS2 score

BACKGROUND

Atrial fibrillation (AF) is associated with an increased risk of dementia. However, limited data are available on the predictors of dementia in patients with AF. This study aimed to evaluate whether the CHADS2 score could be a useful tool for risk stratification with regard to dementia occurrence among patients with AF.

METHODS

AF patients were identified from the National Health Insurance sampling database, which has accumulated a total of 1,000,000 participants since 2000. After excluding patients diagnosed with dementia prior to the index day of enrollment, CHADS2 score was measured to investigate its association with the occurrence of dementia, including vascular dementia and Alzheimer's disease.

RESULTS

During the mean follow-up period of 3.71 ± 2.78 years, 1135 dementia cases (7.36%) were identified, including 241 cases of vascular dementia and 894 cases of Alzheimer's disease. In multivariate analysis, an increase of 1 point in the CHADS2 score was independently associated with a 54% increase in the risk of vascular dementia (hazard ratio = 1.54; 95% confidence interval, 1.41-1.69; p < 0.001) and a 40% increase in Alzheimer's disease (hazard ratio = 1.40; 95% confidence interval, 1.34-1.46; p < 0.001).

CONCLUSION

CHADS2 score is a useful predictor for the development of vascular dementia as well as Alzheimer's disease in patients with AF.

Left atrial thrombus resolution in atrial fibrillation or flutter: Results of a prospective study with rivaroxaban (X-TRA) and a retrospective observational registry providing baseline data (CLOT-AF)

BACKGROUND

Data on left atrial/left atrial appendage (LA/LAA) thrombus resolution after non-vitamin K antagonist (VKA) oral anticoagulant treatment are scarce. The primary objective of X-TRA was to explore the use of rivaroxaban for the resolution of LA/LAA thrombi in patients with nonvalvular atrial fibrillation (AF) or atrial flutter, with the CLOT-AF registry providing retrospective data after standard-of-care therapy in this setting.

METHODS

X-TRA was a prospective, single-arm, open-label, multicenter study that investigated rivaroxaban treatment for 6 weeks for LA/LAA thrombus resolution in patients with nonvalvular AF or atrial flutter and LA/LAA thrombus confirmed at baseline on a transesophageal echocardiogram (TEE). CLOT-AF retrospectively collected thrombus-related patient outcome data after standard-of-care anticoagulant treatment for 3 to 12 weeks in patients with nonvalvular AF or atrial flutter who had LA/LAA thrombi on TEE recorded in their medical file.

RESULTS

In X-TRA, patients were predominantly (95.0%) from Eastern European countries. The adjudicated thrombus resolution rate was 41.5% (22/53 modified intention-to-treat [mITT] patients, 95% CI 28.1%-55.9%) based on central TEE assessments. Resolved or reduced thrombus was evident in 60.4% (32/53 mITT patients, 95% CI 46.0%-73.6%) of patients. In CLOT-AF, the reported thrombus resolution rate was 62.5% (60/96 mITT patients, 95% CI 52.0%-72.2%) and appeared better in Western European countries (34/50; 68.0%) than in Eastern European countries (26/46; 56.5%).

CONCLUSION

X-TRA is the first prospective, multicenter study examining LA/LAA thrombus resolution with a non-VKA oral anticoagulant in VKA-naïve patients or in patients with suboptimal VKA therapy. Rivaroxaban could be a potential option for the treatment of LA/LAA thrombi.

Respiratory Distress in an Infant: An Uncommon Cause for a Common Complaint

BACKGROUND

Respiratory distress and tachycardia are common presenting complaints in infants and young children, and evaluation typically focuses on respiratory infections. Tachydysrhythmias causing heart failure are rare and can be difficult to diagnose in young children, but are reversible if recognized and treated early.

CASE REPORT

We discuss a 7-week-old female infant who presented with respiratory distress and persistent tachycardia. Evaluation revealed severe cardiac dysfunction with an underlying atrial flutter discovered on electrocardiography after adenosine administration. Rate control by synchronized electrocardioversion resulted in resolution of symptoms and restoration of cardiac function, confirming the diagnosis of atrial flutter-induced cardiomyopathy. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Persistent or inappropriate tachycardia in a young child should not be dismissed and underlying dysrhythmia should be considered.

Massive Right Atrial Thrombus Formation Followed by an Atrial Flutter with 1:1 Atrioventricular Conduction in a Patient with Arrhythmogenic Right Ventricular Cardiomyopathy

A 46-year-old man was admitted to our hospital for near syncope and palpitations. An electrocardiogram showed a common type of atrial flutter (AFL) with 1:1 atrioventricular conduction. Transthoracic echocardiography revealed a massive right atrial (RA) thrombus with a huge RA and right ventricle. The patient was diagnosed with arrhythmogenic right ventricular cardiomyopathy. It was difficult to control the heart rate with beta-blockers during AFL, which resulted in the deterioration of right-sided heart failure. The effect of anticoagulation therapy for the RA thrombus was also limited. Restoration to sinus rhythm by catheter ablation effectively improved the right-sided heart failure, and the massive RA thrombus eventually disappeared.

[Detection of Signs of Thrombus Formation in Patients With Typical Atrial flutter]

AIM

to assess rate of detection of markers of thrombi formation and to determine whether transthoracic echocardiography data or clinical characteristics predict severe left atrial appendage [LAA] dysfunction (low LAA velocity, severe spontaneous echo contrast [SEC], LAA thrombus) in patients with typical atrial flutter (AFI).

MATERIAL AND METHODS

Consecutive 406 patients (299 with atrial fibrillation [AFib] and 107 with AFI) underwent transesophageal echocardiography before cardioversion. Mean age was 59.3 years, mean CHA2DS2-VASc score--1.86, mean LAA velocity--37.02 cm/s.

RESULTS

Compared with patients with AF those with AFI had lower rate of detection of markers of thrombi formation (p < 0.05). Among patients with AFI 1.8% had SEC grade 4+, 7.4%--LAA velocity ≤ 25 cm/s. LAA thrombus was found in 2.8 and 8.1% of patients with AFI and AFib, respectively. Prevalence of thrombi in left ventricular (LV) cavity was significantly higher in patients with AFI (3.13 vs. 0.3% in patients with AFib, p = 0.02). In patients with AFI systolic LV dysfunction was the main and ost significant predictor of severe LAA dysfunction and presence LV thrombus.

CONCLUSION

AFI associated high risk of embolic events is primarily determined by its adverse effect on LV function.

Impacts of patient characteristics on the effectiveness of landiolol in AF/AFL patients complicated with LV dysfunction: Subgroup analysis of the J-Land study

Introduction

Results from the multicenter trial (J-Land study) of landiolol versus digoxin in atrial fibrillation (AF) and atrial flutter (AFL) patients with left ventricular (LV) dysfunction revealed that landiolol was more effective for controlling rapid HR than digoxin. The subgroup analysis for patient characteristics was conducted to evaluate the impact on the efficacy and safety of landiolol compared with digoxin.

Methods

Two hundred patients with AF/AFL, heart rate (HR) ≥ 120 beats/min, and LV ejection fraction (LVEF) 25–50% were randomized to receive either landiolol (n = 93) or digoxin (n = 107). Successful HR control was defined as ≥20% reduction in HR together with HR < 110 beats/min at 2 h after starting intravenous administration of landiolol or digoxin. The subgroup analysis for patient characteristics was to evaluate the impact on the effectiveness of landiolol in AF/AFL patients complicated with LV dysfunction.

Results

The efficacy in patients with NYHA class III/NYHA class IV was 52.3%/35.3% in landiolol, and 13.8%/9.1% in digoxin (p < 0.001 and p = 0.172), lower LVEF (25–35%)/higher LVEF (35–50%) was 45.7%/51.1% in landiolol, and 14.0%/12.7% in digoxin (p < 0.001 and p < 0.001), CKD stage 1 (90 < eGFR)/CKD stage 2 (60 ≤ eGFR < 90)/CKD stage 3 (30 ≤ eGFR < 60)/CKD stage 4 (15 ≤ eGFR < 30) was 66.7%/59.1%/39.6%/66.7% in landiolol, and 0%/13.8%/17.0%/0% in digoxin (p = 0.003, p < 0.001, p = 0.015 and p = 0.040).

Conclusions

This subgroup analysis indicated that landiolol was more useful, regardless of patient characteristics, as compared with digoxin in AF/AFL patients complicated with LV dysfunction. Particularly, in patients with impaired renal function, landiolol should be preferred for the purpose of acute rate control of AF/AFL tachycardia.

Electronic supplementary material

The online version of this article (doi:10.1007/s12325-014-0111-2) contains supplementary material, which is available to authorized users.

Radiofrequency ablation of post-incisional atrial flutter and high-output heart failure in a patient with interrupted inferior vena cava and hereditary hemorrhagic telangiectasia

A 61-year-old female with a history of secundum atrial septal defect repair and hereditary hemorrhagic telangiectasia presented with epistaxis. She was found to have atypical atrial flutter with 2:1 atrioventricular conduction. Radiofrequency ablation was planned, but inferior vena cava interruption precluded right atrial (RA) access. The RA was then accessed through both subclavian veins, and activation mapping revealed a dense atriotomy scar in the posterolateral inferior RA. Wavefront propagation proceeded caudally through an area of slow conduction confined by the atriotomy scar. Atypical atrial flutter terminated during a second radiofrequency application to an isthmus confined by 2 regions of dense scar. The arrhythmia did not recur, although the patient later experienced typical atrial flutter and atrial fibrillation. High-output heart failure due to systemic arteriovenous shunt was confirmed by cardiac catheterization and improved markedly with bevacizumab therapy.

Sotalol as first-line treatment for fetal tachycardia and neonatal follow-up

OBJECTIVES

In fetal tachycardia, pharmacological therapy with digoxin, flecainide and sotalol has been reported to be effective. In a recent retrospective multicenter study, sotalol was considered to be less effective than the other drugs in treatment of fetal supraventricular tachycardia (SVT). The aim of this study was to re-evaluate the efficacy and safety of maternally administered sotalol in the treatment of fetal tachycardia.

METHODS

This was a retrospective review of the records of 30 consecutive fetuses with tachycardia documented on M-mode echocardiography between January 2004 and December 2010 at Wilhelmina Children's Hospital, a tertiary referral university hospital. Patients were subdivided into those diagnosed with supraventricular tachycardia and those with atrial flutter (AF) and presence of hydrops was noted. Other variables investigated included QTc interval measured on maternal electrocardiogram before and after initiation of antiarrhythmic therapy, fetal heart rhythm and heart rate pre- and postnatally, oral maternal drug therapy used, time to conversion to sinus rhythm (SR), percentage of fetuses converted following transplacental treatment, maternal adverse effects, presence or absence of tachycardia as noted on postnatal ECG, postnatal therapy or prophylaxis and neonatal outcome. Findings are discussed with reference to the literature.

RESULTS

A total of 28 patients (18 with SVT, 10 with AF) were treated with sotalol as first-line therapy. Fetal hydrops was present in six patients (five with SVT, one with AF). All hydropic patients converted antenatally to SR (67% with sotalol as a single-drug therapy, 33% after addition of flecainide). Of the non-hydropic patients, 91% converted to SR (90% with sotalol only, 10% after addition of flecainide or digoxin). In 9% (with AF) rate control was achieved. There was no mortality. No serious drug-related adverse events were observed. Postnatally, rhythm disturbances were detected in 10 patients, two of whom still had AF. In eight, SVT was observed within 3 weeks postnatally, and in five of these within 72 hours.

CONCLUSIONS

Sotalol can be recommended as the drug of first choice for treatment of fetal AF and has been shown to be an effective and safe first-line treatment option for SVT, at least in the absence of hydrops. Postnatal maintenance therapy after successful prenatal therapy is not necessarily indicated, as the risk of recurrence is low beyond 72 hours of age.