The Role of 24-Hour Holter Electrocardiogram in the Early Detection of Atrial Fibrillation in Newly Diagnosed Acute Ischemic Stroke Patients.

Introduction Stroke is a leading cause of death and disability globally, with atrial fibrillation (AF) recognized as a significant risk factor due to its association with increased stroke recurrence and mortality. Timely detection of AF is crucial to prevent recurrent strokes and improve outcomes. This study primarily aimed to evaluate the utility of 24-hour Holter monitoring for AF detection in acute ischemic stroke patients. Methods This retrospective observational study examined data from 207 patients admitted with acute ischemic stroke to a tertiary-care hospital over a two-year period. Patients with pre-existing AF, transient ischemic attacks, unconfirmed diagnoses, and missing Holter reports were excluded. A total of 140 patients were included in the analysis. The study investigated AF detection rates, the relationship between AF and stroke risk factors, other Holter findings, and the time delay in attaching Holter monitors. Results Of the 140 patients evaluated, AF was detected in nine (6.4%), exclusively in those aged ≥65 years. The most prevalent risk factors among the study participants were hypertension (74.3%) and diabetes (61.4%). No significant correlations were observed between AF and the analyzed stroke risk factors. The median delay for Holter device attachment was 3,503 minutes (approximately two days and 10 hours), with longer delays noted in males (4,084 mins (approximately two days and 20 hours) vs. 2,565 mins (approximately one day and 18 hours), p=0.005). Premature atrial complexes (PACs) were notably associated with the absence of AF, suggesting their potential role as markers for undiagnosed AF. Conclusion The study highlights the limited utility of 24-hour Holter monitoring in detecting AF in acute ischemic stroke patients, advocating for extended monitoring durations, especially in older patients. To improve AF detection, potential strategies include using longer monitoring periods and optimizing hospital workflows to reduce delays in attaching Holter devices. These approaches can minimize the risk of underdiagnosing paroxysmal AF, thereby preventing recurrent strokes and improving patient outcomes. Further investigation into PACs as potential predictive markers for AF is warranted.

Association Between ß-thalassemia and Atrial Fibrillation: Insights from the United States National Inpatient Sample.

Transfusion-dependent ß-thalassemia (thalassemia major and thalassemia intermedia) (BT) requires repeated blood transfusions for survival due to ineffective erythropoiesis. Consequently, iron overload can predispose the patient to atrial fibrillation (AF) despite the improved prognosis achieved with transfusion and chelation therapy. We sought to study the impact of AF on BT patients through a large database analysis. The current study used data from the Agency for Healthcare Research and Quality's Healthcare Cost and Utilization Project National Inpatient Sample collected from 2016-2019. A total of 17,150 admissions were included, of which 2100 (12.2%) admissions had a concomitant diagnosis of AF. Admissions with AF were older (mean age, 72.1 vs. 47.3 years; P < .001) and more likely to have congestive heart failure (CHF), hypertension, valvular heart disease, and renal disease. BT admission was associated with a higher AF prevalence than non-BT admission across all age groups. AF was not associated with an increased risk of in-hospital mortality (adjusted odds ratio [aOR], 1.36; 95% confidence interval [CI], 0.67-2.78; P = .398) or an increased length of stay (LOS) (aOR, 1.00; 95% CI, 0.78-1.29; P = .997) in the general cohort. In a subgroup analysis, AF was associated with increased in-hospital mortality in women (aOR, 2.73; 95% CI, 1.09-6.8; P = .031). Predictors of in-hospital mortality were increasing age, CHF, and liver disease, while predictors of prolonged LOS were diabetes mellitus, CHF, and increasing age. Further studies are warranted to develop strategies to improve the quality of care and outcome in this population.

The Clinical Associations With The Differences in Rivaroxaban Dosing in Patients with Atrial Fibrillation Stratified by three Renal Function Formulae

Background: Clinical trials used Cockcroft-Gault (CG) formula to calculate the estimated glomerular filtration rate (eGFR) in order to dose rivaroxaban for patients with atrial fibrillation (AF). Objectives: The aim of this study is to evaluate rivaroxaban dosing appropriateness in patients with AF with or without renal impairment based on the CG formula and other formulae, including Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation and the isotope dilution mass spectrometry (IDMS) traceable Modification of Diet in Renal Disease (MDRD) Study equation and the associated clinical outcomes. Methodology: A retrospective cohort study conducted at Sultan Qaboos University Hospital (SQUH) from 1st January 2016 to 31st December 2020, included all adult patients (≥ 18 years) treated with rivaroxaban for AF and followed up for one year after starting the treatment. Results: Based on the CG formula, the rivaroxaban dose was inappropriately prescribed in 27% of the patients (21% overdosed and 6% underdosed). Higher baseline creatinine (P=0.0014) and concurrent use of antiplatelet therapy (P<0.001) were associated with the tendency to rivaroxaban overdosing. Higher Body Mass Index (BMI) (P=0.002), female sex (P=0.032), and CKD (P=0.003) were associated with rivaroxaban underdosing. The degree of agreement between the renal function tests when comparing MDRD vs CG and CKD-EPI vs CG in terms of estimated glomerular filtration rate/creatine clearance (eGFR/CrCl) calculation was moderate (κ=0.46) and poor (κ=0.00), respectively, while, in terms of rivaroxaban dose appropriateness was almost perfect (κ=0.82) and substantial (κ=0.77). Clinical outcomes measured by stroke and bleeding events were not significantly different according to the appropriateness of the rivaroxaban dose. (AU)

Novel Oral Anticoagulants in Patients With Atrial Fibrillation and Moderate to Severe Mitral Stenosis: A Systematic Review.

The use of novel oral anticoagulants (NOAC) in patients with moderate to severe mitral stenosis (MS) and atrial fibrillation (AF) is not recommended. We aimed to evaluate the efficacy and safety of NOAC usage compared to vitamin K antagonist (VKA) in patients with moderate to severe MS and AF. We conducted a systematic review to identify articles that compared warfarin to NOAC in patients with moderate to severe MS and AF. Only four studies (two observational studies and two trials) met our search criteria and reported a total of 7529 patients with MS and AF with MS and AF, 4138 of them treated with NOAC. In both observational studies, the severity of MS was not determined, and there was heterogeneity in MS etiology. Nevertheless, both studies showed a positive signal toward the efficacy and safety of NOAC compared to VKA in this population. A randomized pilot trial (n=40) was done on patients with moderate to severe MS, and it showed further acceptable efficacy and safety for rivaroxaban use. However, a larger randomized controlled trial (n=4531) disclosed that VKA (warfarin) led to a significantly lower rate of a composite of cardiovascular events or mortality than rivaroxaban, without a higher rate of major bleeding but not fatal bleeding. Our systematic review provides exploratory information on NOAC safety and effectiveness in patients with MS; it also discourages using NOACs for patients with moderate to severe MS and supports the current treatment guidelines. However, more dedicated clinical trials evaluating the use of NOACs in moderate to severe MS are underway. They will categorically establish the safety profile and clinical effectiveness of NOAC in this high-risk population.

Agro-ecological landuse transformation in oasis systems of Al Jabal Al Akhdar, northern Oman.

The millenia-old oasis systems in the Western Hajar Mountains of Northern Oman have received widespread attention as models of sustainable irrigated agriculture in hyperarid Arabia. Given Oman's rampant urbanization, growing scarcity of water and skilled labour, we quantified chances in water use, land use, and land cover between 2007 and 2018 using a rare time-series approach of detailed GIS-based crop mapping. Results from satellite image analysis and comprehensive ground truthing showed that urban areas grew from 206 ha in 2009 to 230 ha in 2014 and 252 ha in 2018. Throughout this decade, irrigated areas in backyards and front-house gardens of the town, planted largely to tree crops and vegetables, increased from 13.5 to 23.3 ha. Between 2007 and 2018 the actively used area of the studied oasis systems declined by 2.0% and the share of perennial crops without underplanting by 5.1%, while land under agroforestry increased by 2.1% and fallow land by 3.5%. Rising water demand of the sprawling town Sayh Qatanah led to terraces of Al 'Ayn and Ash Sharayjah now being partly irrigated with treated wastewater which accelerated the abandonment of the old settlement structures. The labour- and water use efficiency-driven transformation of the Al Jabal Al Akhdar oasis agriculture into increasingly market-oriented landuse systems questions its function as example of sustainable, bio-cultural heritage of Arabia.

Incidence of Left Atrial Appendage Triggers in Patients With Atrial Fibrillation Undergoing Catheter Ablation.

OBJECTIVE: This study sought to investigate incidence of left atrial appendage (LAA) triggers of atrial fibrillation (AF) and/or organized atrial tachycardias (OAT) in patients undergoing AF ablation and to evaluate outcomes after ablation. BACKGROUND: Although LAA isolation is being increasingly performed during AF ablation, the true incidence of LAA triggers for AF remains unclear. METHODS: All patients with LAA triggers of AF and/or OAT during AF ablation from 2001 to 2017 were included. LAA triggers were defined as atrial premature depolarizations from the LAA, which initiated sustained AF and/or OAT. RESULTS: Out of 7,129 patients undergoing AF ablation over 16 years, LAA triggers were observed in 21 (0.3%) subjects (age 60 ± 9 years; 57% males; 52% persistent AF). Twenty (95%) patients were undergoing repeat ablation. The LAA was the only nonpulmonary vein trigger in 3 patients; the remaining 18 patients had both LAA and other nonpulmonary vein triggers. LAA triggers were eliminated in all patients (focal ablation in 19 patients; LAA isolation in 2 patients). Twelve months after ablation, 47.6% remained free from recurrent arrhythmia. After overall follow-up of 5.0 ± 3.6 years (median: 3.7 years; interquartile range: 1.4 to 8.9 years), 38.1% were arrhythmia-free. All 3 patients with triggers limited to the LAA remained free of AF recurrence. One patient undergoing LAA isolation developed LAA thrombus during follow-up. CONCLUSIONS: The incidence of true LAA triggers is very low (0.3%). Most patients with LAA triggers have additional nonpulmonary vein triggers, and despite elimination of LAA triggers, long-term arrhythmia recurrence rates remain high. Potential risks of empiric LAA isolation during AF ablation (especially first-time AF ablation) may outweigh benefits.

Incidence and Predictors of Intracardiac Thrombus on Pre-electrophysiological Procedure Transesophageal Echocardiography.

BACKGROUND: Cerebral thromboembolism is a potentially devastating complication of atrial fibrillation (AF) and atrial flutter (AFl). The use of transesophageal echocardiogram (TEE) before electrophysiological procedures in anticoagulated patients is variable. Our objective was to determine the incidence and identify predictors of intracardiac left atrial appendage (LAA) thrombus on TEE in patients with AF/AFl before electrical cardioversion or ablation. METHODS: We reviewed TEEs of 401 patients undergoing an electrical cardioversion, AF, or AFl ablation from April 2013 to September 2015 at the McGill University Health Center. Clinical and echocardiographic variables were collected at the time of the TEE and follow-up visits. Multivariate logistic regression was used to determine predictors of LAA thrombus. RESULTS: Of 401 patients, 11.2% had LAA thrombus on TEE. The majority (87%) of patients were anticoagulated for at least 3 weeks before the TEE. The incidence of LAA thrombus was 21% (23/110) in patients taking warfarin vs 6.4% (15/236) in patients taking direct oral anticoagulants. Multivariate analysis identified prior stroke (odds ratio [OR], 2.7; 95% confidence interval [CI], 1.1-6.9) and heart failure (OR, 2.2; 95% CI, 1.0-4.7) as predictors of thrombus, whereas direct oral anticoagulant use (OR, 0.4; 95% CI, 0.2-0.8) was associated with reduced odds of thrombus. CONCLUSIONS: LAA thrombus was identified in a significant proportion of patients undergoing TEE before cardioversion or ablation of AF/AFl despite preprocedural anticoagulation. Patients at increased risk of LAA thrombus (heart failure and prior stroke) may benefit from TEE before cardioversion, AF, or AFl ablation.

INTRODUCTION: La thromboembolie cérébrale est une complication potentiellement dévastatrice de la fibrillation auriculaire (FA) et du flutter auriculaire. L'utilisation de l'échocardiographie transœsophagienne (ETO) avant les interventions en électrophysiologie chez les patients anticoagulés est variable. Notre objectif était de déterminer la fréquence et les prédicteurs des thrombi intracardiaques dans l'appendice auriculaire gauche (AAG) à l'ETO chez les patients atteints de FA ou de flutter auriculaire avant de procéder à une cardioversion électrique ou à une ablation. MÉTHODES: Nous avons passé en revue les ETO de 401 patients qui avaient subi une cardioversion électrique, ou une ablation de la FA ou du flutter auriculaire entre avril 2013 et septembre 2015 au Centre universitaire de santé McGill. Nous avons recueilli les variables cliniques et échocardiographiques au moment de l'ETO et des visites de suivi. Nous avons utilisé la régression logistique multivariée pour déterminer les prédicteurs de thrombus dans l'AAG. RÉSULTATS: Parmi les 401 patients, 11,2 % avaient un thrombus dans l'AAG à l'ETO. La majorité (87 %) des patients étaient anticoagulés au moins 3 semaines avant l'ETO. La fréquence des thrombus dans l'AAG était de 21 % (23/110) chez les patients qui prenaient de la warfarine vs 6,4 % (15/236) chez les patients qui prenaient des anticoagulants oraux directs. L'analyse multivariée a permis d'établir que l'accident vasculaire cérébral (AVC) antérieur (ratio d'incidence approché [RIA], 2,7; intervalle de confiance [IC] à 95 %, 1,1-6,9) et l'insuffisance cardiaque (RIA, 2,2; IC à 95 %, 1,0-4,7) étaient des prédicteurs de thrombus, alors que l'utilisation d'anticoagulants oraux directs (RIA, 0,4; IC à 95 %, 0,2-0,8) était associée une probabilité moindre de thrombus. CONCLUSIONS: Une proportion importante de patients qui avaient subi l'ETO avant la cardioversion, ou l'ablation de la FA ou du flutter auriculaire avaient un thrombus dans l'AAG en dépit de l'anticoagulation avant l'intervention. Les patients exposés à un risque accru de thrombus dans l'AAG (insuffisance cardiaque et AVC antérieur) peuvent bénéficier de l'ETO avant la cardioversion, ou l'ablation de la FA ou du flutter auriculaire.

Assessment and Management of the Left Atrial Appendage Thrombus in Patients With Nonvalvular Atrial Fibrillation.

BACKGROUND: Intracardiac thrombi arising in the left atrial appendage (LAA) are the principal cause of stroke in nonvalvular atrial fibrillation (AF). Predicting the presence of LAA thrombi is of vital importance in stratifying patients that would need further LAA imaging prior to cardioversion or AF ablation. METHODS: We comprehensively searched PubMed from its inception to November 2017 for randomized controlled trials, cohort and case control studies, as well as for case series on LAA thrombi risk factors, imaging, prevention, and anticoagulation management in atrial fibrillation. RESULTS: A systematic review of the literature identified 106 articles that investigated the presence of LAA thrombi in AF patients. We classified the articles according to topic and reported on: (1) risk factors; (2) diagnostic imaging modalities; (3) prevention strategies before cardioversion; (4) prevention strategies before AF ablation; and (5) management of detected LAA thrombi. CONCLUSIONS: Integration of clinical, biomarker, and imaging risk factors can improve overall prediction for the presence of LAA thrombi, translating into improved patient selection for imaging. The gold standard for the diagnosis of LAA thrombi remains transesophageal echocardiography, although intracardiac ultrasound, cardiac computed tomography, and cardiovascular magnetic imaging are promising alternative modalities. When LAA thrombi are discovered, the treatment regimen remains variable, although direct oral anticoagulants might have efficacy similar to vitamin K antagonists. Future trials will help further elucidate direct oral anticoagulant use for the treatment of LAA thrombi.

Pericardial fat and atrial fibrillation: Epidemiology, mechanisms and interventions.

Atrial fibrillation (AF) is the most common cardiac arrhythmia in clinical practice and is associated with major morbidity and mortality. AF prevalence has been projected to increase in the coming decades and is expected to affect over 7.5 million Americans by the year 2050. There is growing evidence that obesity represents an important risk factor for new onset AF, with each increment in BMI associated with a 3-8% higher risk for new-onset of AF, independent of other conventional AF risk factors such as age, hypertension and heart failure. Several recent studies have also reported that obesity is also a risk factor for AF severity & chronicity. Although obesity may impact AF incidence via several mechanisms, a relation between local pericardial fat depots surrounding the heart and AF has been recently described which may have important pathophysiological implications. Pericardial fat represents one of several localized, fat depots, with unique properties due to its contiguity with cardiac structures and its shared blood supply with the heart microcirculation. Pericardial fat is also highly metabolically active and is an important source of several adipokines and cytokines. Importantly, pericardial fat appears to be more closely linked with metabolic risk than indices of systemic obesity such as BMI or waist circumference. Therefore, pericardial fat may partially explain the increased risk of AF seen in obesity and may promote AF arrhythmogenesis by local mechanisms. In this article, we review the characteristics of pericardial fat, the evidence of an association between pericardial fat and AF and the potential mechanisms for this association. We also summarize the evidence from several recent reports that have linked pericardial fat to AF prevalence, severity as well as outcome after AF ablation. We also briefly review whether interventions targeting pericardial fat could reduce AF incidence and recurrence.

Neurofibromatosis with bilateral renal artery stenosis and end stage renal disease: case report.

Neurofibromatosis type 1 (NF-1) is an autosomal dominant, hereditary, neurocutaneous syndrome that may, primarily or secondarily, affect different organs or systems of the body including the cardiovascular system. The most common vascular abnormality in patients with NF-1 is renal artery stenosis. Here we report the case of a middle-aged gentleman who presented at Sultan Qaboos University Hospital, Oman, with end stage renal disease and severe hypertension and was diagnosed to have NF-1 with bilateral renal artery stenosis. He was started on renal replacement therapy.