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.

Safety and efficacy of apixaban, dabigatran and rivaroxaban in obese and morbidly obese patients with heart failure and atrial fibrillation: A real-world analysis.

BACKGROUND: Atrial fibrillation and heart failure are combined risk factors for thromboembolic events. Obese and morbidly obese individuals have been underrepresented in clinical trials studying safety and efficacy of direct oral anticoagulants (DOACs). OBJECTIVES: Study the comparative safety and efficacy of DOACs in obese and morbidly obese patients with atrial fibrillation or flutter, and concomitant congestive heart failure. METHODS: In the present single-center retrospective observational study, patients with an ICD-9 code of atrial fibrillation or atrial flutter, and congestive heart failure on a DOAC (apixaban[n = 155], rivaroxaban[n = 335], dabigatran[n = 393]) were followed for a median 12.5 months (IQR: 22.1 months). Obesity was defined as a body mass index, BMI ≥ 30 and < 40 kg/m2 [n = 614], and morbid obesity as BMI ≥ 40 kg/m2 [n = 269]. Clinical endpoints were grouped into safety (composite of intracranial-hemorrhage, gastrointestinal-bleeds, hemorrhagic-stroke, and other bleeds), and efficacy (composite of ischemic-stroke and systemic-embolism) endpoints. Cox proportional hazard models were used to compare safety, efficacy, and all-cause mortality outcomes. RESULTS: In obese patients, no statistical difference was observed in efficacy of DOACs. A statistical difference was observed in the safety of DOACs in obese patients. Apixaban was found to be safer than dabigatran [hazard ratio [HR] 0.37 (0.16-0.87), p = .02] and rivaroxaban [HR 0.29 (0.12-0.67), p = .004]. In morbidly obese patients, there was no overall statistical difference in the efficacy or safety of DOACs. CONCLUSION: In obese patients with congestive heart failure and atrial fibrillation or atrial flutter on DOACs, apixaban has the most favorable safety profile compared to rivaroxaban and dabigatran.

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.

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.

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 Pinteraction > 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.

Prediction of Atrial Fibrillation Being Asymptomatic at First Onset by Cardiac Pacing.

Asymptomatic or silent atrial fibrillation (AF) has long been a clinical problem due to the incidence of ischemic stroke. A method is needed to predict the development of silent AF before the occurrence of ischemic stroke. This study was focused on the symptoms of AF, especially palpitation, in pacemaker patients. We assessed the hypothesis that absence of palpitation during rapid ventricular pacing could be a predictor of future onset AF being asymptomatic.In this study, we assessed the presence of symptoms during RV pacing and AF symptoms on 145 pacemaker patients at the outpatient clinic by VVI pacing at 120 ppm. The relationship between symptoms during RV pacing and symptom during AF was assessed. The predictive value of absence of symptom during RV pacing on AF being asymptomatic was assessed.Of 145 patients, 74 had previous AF episode. Among the AF patients, absence of symptom during VVI pacing was associated with AF being asymptomatic.Of 145 patients, 71 had no previous AF events. There were 14 patients who had new-onset AF or atrial flutter (AFL) after the device implantation. Four of the 14 patients (28.6%) were symptomatic during first AF/AFL episode, and 10 (71.4%) were asymptomatic during first-onset AF. All ten patients who were asymptomatic during cardiac pacing test were asymptomatic during their initial episodes of AF as well.This study showed that absence of symptoms during rapid ventricular pacing was associated with first-onset AF being asymptomatic.

The Risk of Ventricular Tachyarrhythmias in Patients with Antimitochondrial Antibodies-Related Noncardiac Diseases.

Antimitochondrial antibodies (AMA) are serum autoantibodies specific to primary biliary cholangitis and are linked to myopathy and myocardial damage; however, the presence of AMA as a risk factor for ventricular tachyarrhythmias (VTs) has remained unknown. This study aimed to elucidate whether the presence of AMA-related noncardiac diseases indicates VTs risk.This cohort study enrolled 1,613 patients (883 females) who underwent AMA testing to assess noncardiac diseases. The incidence of VTs and supraventricular tachyarrhythmias (SVTs) from a year before the AMA testing to the last visit of the follow-up were retrospectively investigated as primary and secondary objectives. Using propensity score matching, we extracted AMA-negative patients whose covariates were matched to those of 152 AMA-positive patients. In this propensity score-matched cohort, the incidence of VTs and SVTs in the AMA-positive patients were compared with that in AMA-negative patients.The AMA-positive patients had higher estimated cumulative incidence (log-rank, P = 0.013) and prevalence (5.9% versus 0.7%, P = 0.020) of VTs than the AMA-negative patients. The presence of AMA was an independent risk factor for VTs (hazard ratio, 4.02; 95% CI, 1.44-20.01; P = 0.005). Meanwhile, AMA were associated with atrial flutter and atrial tachycardia development. In AMA-positive patients, VTs were associated with male sex, underlying myopathy, high creatine kinase levels, presence of chronic heart failure or ischemic heart disease, left ventricular dysfunction, presence of SVTs, and the electrocardiographic parameters indicating atrial disorders.The presence of AMA-related noncardiac diseases is an independent risk factor for VTs.

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.

Remote magnetic navigation ablation via the right jugular vein approach in patient with interruption of the inferior vena cava and incessant left atrial flutter.

Remote magnetic navigation (RMN) can be safely and effectively utilized in patients with difficult cardiac arrhythmias and complex anatomy. Interruption of the inferior vena cava (IVC) is a rare congenital abnormality that results in the inability to use conventional femoral access in patients that require interventional procedures. The present case demonstrates the feasibility of left atrial flutter ablation using RMN via jugular approach in a patient with interruption of IVC.

Association of Fetal Atrial Flutter with Neonatal Atrioventricular Re-entry Tachycardia Involving Accessory Pathway: A Link to be Remembered.

To investigate prenatal and postnatal outcomes of atrial flutter and its association with the development of a second tachycardia, following restoration of sinus rhythm, in the fetus or newborn. This study is a retrospective review of all fetuses that presented with atrial flutter from January 2001 to December 2019 at the University Hospital of Wales, Cardiff, UK. The specific type of arrhythmia, its time of appearance and clinical characteristics, echocardiographic findings, medical management, and postnatal outcomes were evaluated. Sixteen fetuses were diagnosed with atrial flutter (AFL). Thirteen fetuses had persistent AFL and three fetuses had intermittent AFL. Seven patients had hydrops, of which one had Ebstein's anomaly and the other six had normal hearts. Three of the fetuses that presented with AFL were diagnosed at 20, 21, and 23 weeks' gestation and the remainder were diagnosed in the third trimester. Thirteen patients with AFL received antiarrhythmic drugs and three were delivered without any treatment. Five fetuses with AFL developed atrioventricular reciprocating tachycardia following DC cardioversion after birth, and four of them exhibited pre-excitation on the ECG. These five patients (31.3%) required postnatal antiarrhythmic treatment for up to 2 years. Pre-excitation disappeared in two patients during follow-up and two asymptomatic patients with neonatal pre-excitation required accessory pathway ablation. Fetal atrial flutter has a strong association with atrioventricular reciprocating tachycardia and ventricular pre-excitation in the neonatal period. Therefore, electrocardiograms should be carefully reviewed in newborns following the initial resolution of atrial flutter.

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.

Rate Versus Rhythm Control in Tachycardia-Induced Cardiomyopathy Patients with Persistent Atrial Flutter.

Tachycardia-induced cardiomyopathy (TIC) is a potentially reversible cardiomyopathy caused by tachyarrhythmia. For atrial flutter (AFL) -induced TIC, a rhythm control strategy, such as catheter ablation, has been recommended. However, the efficacy of rate control has remained unclear due to the difficulty of achieving control using arrhythmic medications.We prospectively assessed 47 symptomatic heart failure (HF) patients with left ventricular ejection fraction (LVEF) < 50% and suspected persistent AFL-induced TIC. Patients were divided into the rhythm control strategy (n = 22; treatment with catheter ablation or electrical cardioversion) and rate control strategy (n = 25; treatment with bisoprolol) groups. The latter was further divided into the strict rate control strategy (average heart rate < 80 bpm) and lenient rate control strategy (average heart rate < 110 bpm) subgroups. The primary outcome was left ventricular (LV) function recovery, which was defined as an increase in LVEF ≥ 20% or to a value of ≥ 55% after 6 months.In the rhythm control strategy group, more patients achieved LV function recovery after 6 months (95.2% versus 60.9%, P = 0.010). The cumulative incidence of worsening HF events was significantly higher in the rate control strategy group than in the rhythm control strategy group (hazard ratio, 4.66; 95% confidence interval, 1.01-21.57). The subgroup study revealed the advantage of the strict rate control strategy for achieving LV function recovery (83.3% versus 36.4%, P = 0.036).The rate control strategy was significantly inferior to the rhythm control strategy for the LV function recovery in TIC patients with persistent AFL. Our findings suggest that the strict rate control strategy should be aimed if the rhythm control strategy cannot be performed.

Direct Oral Anticoagulant Use After Transcatheter Aortic Valve Replacement: A Case Series.

BACKGROUND: Use of an anticoagulant after transcatheter aortic valve replacement (TAVR) has been increasing in practice after noted leaflet thrombosis on dual antiplatelet therapy. As the use of anticoagulation increases so does the number of poor warfarin candidates or warfarin intolerant patients. While direct oral anticoagulant (DOAC) use is increasing for other indications, there is a paucity of data for use after TAVR. The objective of this case series is to add to the available evidence for patients who may require a DOAC after TAVR. METHODS: A single-center, retrospective observational case series was conducted including adults 18 years of age and older who received a DOAC after TAVR between November 2008 and June 2018 at Mayo Clinic Hospital-Rochester. All patients were identified as part of the Society of Thoracic Surgeons database. RESULTS: Twenty-one patients were identified as having received a DOAC after TAVR. Median age was 83.5 years (interquartile range 77-87), with 71% males. Within this cohort, 20 patients (95.2%) had an alternative indication for anticoagulation of either atrial fibrillation or atrial flutter. Apixaban was prescribed in 66.7% of patients, followed by rivaroxaban (14.3%), dabigatran (9.5%), and edoxaban (4.8%). No thromboembolic events were reported. Three patients experienced a bleeding event, of which only 2 occurred in the 3 months immediately after TAVR. CONCLUSIONS: DOAC therapy after TAVR was generally safe and well tolerated. Taken in context of other retrospective studies, these data suggest that the presence of valvular heart disease, specifically TAVR in this case, should not preclude the use of DOACs.

Atrial Flutter-Unique Arrhythmia in Neonatal Population, Presentation of 3 Cases.

BACKGROUND: Atrial flutter (AFL) is an uncommon arrhythmia in the pediatric population. It is defined as fast ordered atrial depolarization (about 250-500 beats/min). It occurs mainly in children with congenital heart defects; however, it may also manifest in fetuses and infants with an anatomically healthy heart. In neonates, AFL is most often revealed within the first 2 days after birth. CLINICAL FINDINGS: In this case report, we present 3 neonates without complex congenital heart defects with AFL, along with the description of the course, diagnostic and therapeutic processes depending on the clinical condition of a child, and response to treatment. PRIMARY DIAGNOSIS: Symptoms in this group of patients are nonspecific, that is, tachypnea, unwillingness to eat, and fatigue while feeding. The diagnostic process included thorough electro- and echocardiographic assessments. Each child was treated individually due to a different cause of arrhythmia and comorbidities. INTERVENTIONS: Invasive (electrical cardioversion) and pharmacological methods were used in treatment to achieve conversion to sinus rhythm. OUTCOMES: One patient required electrical cardioversion, one was treated with amiodarone and digoxin, and one infant received amiodarone. All children achieved conversion to sinus rhythm. PRACTICE RECOMMENDATIONS: During the follow-up, each child maintained sinus rhythm, which shows that in the neonatal group, it is a unique, but well-controlled, arrhythmia once conversion to sinus rhythm is achieved.

Catheter ablation of supraventricular tachycardia in patients with dextrocardia and situs inversus.

BACKGROUND: Dextrocardia with situs inversus is a rare cardiac positional anomaly. Catheter ablation procedures performed in this set of patients have not been sufficiently reported. METHODS: A total of 10 patients with dextrocardia and situs inversus who received catheter ablation for supraventricular tachycardia (SVT) were included from a cohort of over 20 000 cases of catheter ablation for SVT in three centers from 2005 to 2016. All patients underwent electrophysiologic study and catheter ablation of SVT. Ablation targets were selected based on different tachycardia mechanisms with the primary endpoint of noninduction of tachycardia. RESULTS: The average age was 32.4 ± 5.6 years. Congenitally corrected transposition of great arteries (TGA) with situs inversus and D-looping of the ventricles and aorta (congenitally corrected TGA {I,D,D}) was found in four patients, while the other six patients exhibited mirror-image dextrocardia {I,L,L}. The mechanisms of SVT were atrioventricular nodal reentrant tachycardia in four patients, atrioventricular reentrant tachycardia in three, typical atrial flutter in one, intra-atrial reentrant tachycardia in one, and focal atrial tachycardia in one. Immediate procedural success was achieved in 9 out of 10 patients with no procedural complications. During a follow-up period of 6.3 ± 3.5 years on average, all patients remained free from recurrent tachycardia. CONCLUSIONS: For patients with dextrocardia and situs inversus, catheter ablation of SVT is safe and feasible. Differences in catheter maneuver and fluroscopy projection, along with difficulties in distorted anatomy are major obstacles for successful ablation.

Differential Effectiveness of Landiolol Between Atrial Fibrillation and Atrial Flutter/Atrial Tachycardia Patients With Left Ventricular Dysfunction.

BACKGROUND: Landiolol, an ultra-short acting ß1-selective blocker, is more effective for controlling the heart rate (HR) than digoxin in patients with atrial tachyarrhythmias and left ventricular (LV) dysfunction. The impact of the type of atrial tachyarrhythmias on the effectiveness of landiolol is uncertain. We evaluated the efficacy and safety of landiolol on tachycardiac atrial fibrillation (AF) and tachycardiac atrial flutter/atrial tachycardia (AFl/AT) in patients with reduced LV function. Methods and Results: Seventy-seven patients treated with landiolol were retrospectively analyzed. There were no significant differences in the baseline characteristics between the AF group (n=65) and AFl/AT group (n=12). Despite a higher dosage, the %change in HR from baseline to 12 and 24 h was only -10.2±12.7% and -16.1±19.4% in the AFl/AT group, while it was -28.3±13.2% and -31.3±11.3% in the AF group (P<0.02), respectively. The prevalence of the responders to landiolol treatment was much greater in the AF group than in the AFl/AT group (P<0.001). Alternative treatments such as i.v. amiodarone and electrical cardioversion were required in 83% of the AFl/AT patients. CONCLUSIONS: Landiolol was ineffective in the majority of AFl/AT patients. An alternative management to prevent any worsening of heart failure might be considered in those patients.

Non-vitamin K oral anticoagulants versus warfarin for left atrial appendage thrombus resolution in nonvalvular atrial fibrillation or flutter.

BACKGROUND: Non-vitamin K oral anticoagulants (NOACs) have emerged as alternatives to vitamin K antagonists in select situations. For left atrial (LA) appendage thrombus in nonvalvular atrial fibrillation (AF) or flutter, guidelines recommend oral anticoagulation (OAC) for at least 3 weeks prior to reassessment. Data comparing NOACs to warfarin in this scenario are scarce. METHODS: A retrospective study identified subjects with nonvalvular AF or flutter who were: a) noted to have LA thrombus detected on transesophageal echocardiography (TEE), b) previously not receiving long-term OAC; and c) evaluated for resolution of LA thrombus by follow-up TEE between 3 weeks to less than 1 year of the initial TEE. RESULTS: The study included 45 subjects with mean age 63.2 years, 69% male, 78% white race/ethnicity, 42% paroxysmal, and mean CHA2 DS2 -VASc score 3.4 ± 1.7. All LA thrombi were confined to the appendage. OAC received included apixaban (3), dabigatran (13), rivaroxaban (6), and warfarin (23), The median follow-up time to repeat TEE was 67 (interquartile range, 49-96) days. LA appendage thrombus resolution rates were 76% for the entire cohort, 77% for NOACs, and 74% for warfarin. In univariable logistic regression analysis, LA appendage thrombus resolution was similar for NOACs when compared to warfarin (odds ratio, 1.20; 95% confidence interval, 0.31-4.69; P = .79). CONCLUSIONS: In patients nonvalvular AF or flutter who were OAC naïve at the time of diagnosis with LA appendage thrombus, complete resolution was similar between NOACs and warfarin.

Differentiating spontaneous echo contrast, sludge, and thrombus in the left atrial appendage: Can ultrasound enhancing agents help?

The accurate identification of thrombus in the left atrial appendage with transesophageal echocardiogram (TEE) in patients with atrial fibrillation (AF) before cardioversion is essential. Most of these patients have some grade of spontaneous echo contrast (SEC). Severe SEC is often called "sludge," and its prognosis and treatment are still controversial. Current guidelines suggest the use of ultrasound enhancing agents (UEAs) when significant SEC is present. However, little is known about the utility of the UEAs in the differentiation between sludge and less severe SEC.

Impact of fasciculoventricular bypass tracts on the diagnosis and treatment of concomitant arrhythmias and cardiac diseases.

BACKGROUND: Fasciculoventricular (FV) bypass tracts (BTs) are the rarest form of ventricular preexcitation. Although they are not involved in clinically significant reentrant tachycardia, they may cause diagnostic and therapeutic confusion if not properly understood. This study aimed to assess the impact of FV BTs on the diagnosis and treatment of concomitant arrhythmias and cardiac diseases. METHODS: Twenty-two patients with FV BTs who underwent electrophysiologic (EP) study were evaluated. The prevalence of concomitant arrhythmias and cardiac diseases in FV BTs was evaluated. The mechanisms of concomitant arrhythmias were determined by EP study and cardiac diseases were diagnosed by echocardiography. RESULTS: One patient had FV BT with complete infra-Hisian atrioventricular (AV) block that mimicked a slow ventricular escape rhythm. Two patients had FV BT with atrial fibrillation or atrial flutter, which was misinterpreted as AV BT requiring emergency DC cardioversion. Eight patients had accompanying AV BTs. In 2 patients with AV BTs, unnecessary RF application was delivered after successful ablation of AV BT because conduction through a FV BT was mistaken for conduction through a residual AV BT. Five patients had no concomitant arrhythmia; however, two of them had hypertrophic cardiomyopathy with symptoms requiring beta-blocker. Patients had not been prescribed beta-blockers to avoid a proarrhythmic response before the EP study because the FV BTs mimicked AV BTs. CONCLUSION: FV BTs were frequently accompanied by AV BTs or other arrhythmias and cardiac diseases. They may cause misdiagnosis and inappropriate therapy and even unnecessary RF delivery when misinterpreted as AV BTs.