Management of patients with acute atrial fibrillation in the ED

Background

Patients with acute atrial fibrillation with a history of mild structural heart disease could be considered for rhythm conversion.

Methods

Patients received intravenous flecainide, propafenone, or amiodarone on presentation and a second dose after 6 hours if atrial fibrillation persisted. No randomization was used, and drugs were given at the discretion of the treating physician. Primary end point was rhythm conversion within the first 6 hours from presentation. Secondary end points included rhythm conversion, time to rhythm conversion, and adverse drug effects within 24 hours.

Results

Among the 378 patients enrolled, 37 (10%) recovered sinus rhythm before therapy was given. Of the remaining 341 patients, 43 (13%) received flecainide, 187 (55%) received propafenone, and 111 (32%) received amiodarone. Baseline clinical characteristics were homogeneous among groups. Rhythm conversion was obtained in 87% of treated patients overall. Within 6 hours, the primary end point was achieved in a higher proportion in the flecainide and propafenone groups (72% and 55%, respectively) as compared with the amiodarone group (30%; P < .001). The mean time to the end point overall was shorter in the flecainide and propafenone groups (178 ± 227 and 292 ± 285 minutes, respectively) as compared with the amiodarone group (472 ± 269 minutes; P < .001). Length of in-hospital stay in the amiodarone group was significantly higher (26.1 ± 22.4 hours) compared with the flecainide and propafenone groups (8.9 ± 10.3 and 11.0 ± 13.8 hours; respectively; P = .001). No significant differences were found in adverse drug effects.

Conclusions

Flecainide and propafenone achieve rhythm control in a higher proportion of patients as compared with amiodarone within a 6-hour management.     

Ibutilide to expedite ED therapy for recent-onset atrial fibrillation flutter

OBJECTIVE: Ibutilide is a type III antiarrhythmic agent approved for the pharmacologic conversion of atrial fibrillation (AF) and atrial flutter (AFl). Previous studies conducted outside the ED setting have demonstrated conversion rates of 60% to 80%. This response has been highest in patients with recent-onset AF-AFl. These observations and the 4-hour half-life of ibutilide suggest that it may be an excellent drug with which to treat AF-AFl in the ED. The purpose of the study was to examine the efficacy and safety of ibutilide in terminating AF-AFl in patients who present to the ED with symptoms of less than 3 days' duration, neither angina nor heart failure, and no comorbid conditions that require admission. METHODS: Among 36 enrolled patients, the admission electrocardiogram demonstrated AF in 26 and AFl in 10. Ibutilide 1 mg was administered intravenously for 10 minutes. If sinus rhythm was not present 10 minutes after the infusion concluded, a second infusion of 1 mg was given. Successful conversion was defined as restoration of sinus rhythm within 1 hour after the last dose of ibutilide. RESULTS: Sixteen (61.5%) of 26 patients with AF and 9 (90%) of 10 patients with AFl converted to sinus rhythm (overall conversion rate=69%). The mean time to arrhythmia termination was 19+/-9 minutes. The mean stay in the ED was 16.2 hours. No significant complications occurred. CONCLUSION: We conclude that ibutilide is an excellent therapy option for restoring sinus rhythm in the ED. Its use may obviate the need for admission, avoid the risks and inconveniences of general anesthesia to perform electrical cardioversion, and reduce the ED length of stay in selected patients with recent-onset atrial arrhythmias.     

Assessment of the Framingham risk factors among ED patients with newly diagnosed atrial fibrillation

Study Objective

Atrial fibrillation (AF) is often first diagnosed in the emergency department (ED) and accounts for nearly 1% of all emergency department (ED) visits. Our objective was to assess the Framingham Heart Study risk score for AF development in ED patients with newly diagnosed AF.

Methods

We systematically reviewed the electronic medical records of ED patients with newly diagnosed AF between August 2005 and July 2008. We measured the frequency of the Framingham Heart Study predictors and calculated each patient's risk score.

Results

During the 3-year study period, 914 patients had 1228 ED visits. New AF was diagnosed in 296 (32%) patients. Among these patients, 107 (36%) were female, 127 (43%) had prior ED visits since 2003, 189 (64%) were taking hypertension medications and 170 (57.4%) had previous electrocardiograms with measurable PR intervals. The median PR interval was 166 ms (151 to 180) and 60% of available PR intervals were 160 ms or greater. The median (interquartile range) age, body mass index, and systolic blood pressure were 66 years (53-77), 27 (23-31), and 134 mm Hg (118-151), respectively. Median risk score was 7 (3-9) indicating high predicted risk. Heart failure and cardiac murmurs were previously diagnosed in 45 (15%) and 32 (11%) of these patients, respectively.

Conclusions

The Framingham risk factors for AF are commonly encountered among ED patients with newly diagnosed AF. The ED might provide an opportunity to identify patients at high risk for AF and refer them for primary prevention interventions.     

Predictors of digoxin use and risk of mortality in ED patients with atrial fibrillation

Objectives

The aim of this study was to evaluate factors of digoxin use and its relation to mortality in ED patients with atrial fibrillation (AF).

Double-dose external cardioversion for refractory unstable atrial fibrillation in the ED

A 45-year-old man with dilated cardiomyopathy, atrial fibrillation, and hypertension presented to the emergency department with palpitations and shortness of breath for 2 days after running out of his medications. An electrocardiogram disclosed atrial fibrillation with rapid ventricular response. The patient was hemodynamically unstable and failed multiple cardioversion attempts up to 360 J. A second defibrillator was then attached and the patient successfully cardioverted once both defibrillators were set to their maximum levels, thus delivering a total of 720 J. Double-dose external cardioversion with 2 defibrillators is an important alternative method that the emergency physician should be aware of when treating refractory atrial fibrillation in the hemodynamically unstable patient.     

Evaluating coagulation tests in patients with atrial fibrillation using direct oral anticoagulants

Four direct oral anticoagulants (dabigatran, rivaroxaban, apixaban, edoxaban) have been shown to be at least as effective and safe as warfarin for the prevention of stroke in atrial fibrillation and the prevention and treatment of venous thromboembolism. Although they are administered in fixed doses without routine coagulation monitoring, measurement of anticoagulant effect or drug levels may be useful to determine if: anticoagulant effect is present in patients who are bleeding or require an urgent procedure or thrombolysis; levels are within usual on-therapy range in patients with recurrent thromboembolism during treatment; and levels are outside of the usual on-therapy range in patients with overdose or with extreme clinical characteristics. Traditional coagulation assays are widely available but lack sensitivity to detect clinically relevant anticoagulant effects, and lack accuracy in quantitating drug levels. Specific drug assays are less widely available but can accurately measure drug levels and should be preferred.     

MRI of the left atrium: predicting clinical outcomes in patients with atrial fibrillation

Atrial fibrillation is a significant public health burden, with clinically, epidemiologically and economically significant repercussions. In the last decade, catheter ablation has provided an improvement in morbidity and quality of life, significantly reducing long-term healthcare costs and avoiding recurrences compared with drug therapy. Despite recent progress in techniques, current catheter ablation success rates fall short of expectations. Late gadolinium-enhancement cardiovascular MRI is a well-established tool to image the myocardium and, most specifically, the left atrium. Unique imaging protocols allow for left atrial structural remodeling and fibrosis assessment, which has been demonstrated to correlate with clinical outcomes after catheter ablation, assessment of the individual's risks of thromboembolic events, and effective imaging of patients with left atrial appendage thrombus. Late gadolinium-enhancement MRI aids in the individualized treatment of atrial fibrillation, stratifying recurrence risk and guiding specific ablation strategies. Real-time MRI offers significant safety and effectiveness profiles that would optimize the invasive treatment of atrial fibrillation.     

Evaluating patients with acute ischemic stroke with special reference to newly developed atrial fibrillation in cerebral embolism

BACKGROUND: Cardioembolic strokes are extensive and have a poor prognosis. To identify the cardiovascular risk factors of cardioembolic stroke, we evaluated the cardiovascular status with special reference to persistent atrial fibrillation (AF) and paroxysmal atrial fibrillation (PAF) combined with the type of acute ischemic stroke. METHODS: We divided 315 consecutive patients admitted to our Department of Neurosurgery with an acute ischemic stroke into four types of brain infarction using clinical history, onset pattern of stroke, and brain imaging: cardioembolic (group E, n = 105), lacunar (group L, n = 92), atherothrombotic (group T, n = 111), and unclassified (n = 7). All patients underwent standard electrocardiography (ECG), a 24-hour ECG recording (Holter ECG) and transthoracic echocardiography (UCG). RESULTS: Persistent AF or PAF was detected in 97 patients (31.5%) using Holter ECG: more frequently in group E (67.6%) than in groups L (15.2%) or T (9.2%). Persistent AF or PAF was first diagnosed on admission using a standard ECG in 16 patients (5.2%) with no previous history and 14 of these patients belonged to group E (13.3%). PAF was newly detected on Holter ECG in another 26 patients (8.4%) and 13 of these patients (12.4%) belonged to group E. Concerning UCG, left atrial enlargement and mitral regurgitation were more frequent in group E than in group L or T. CONCLUSION: Holter ECG in addition to ECG on admission is important for detecting persistent AF or PAF in patients with ischemic stroke, especially with cardioembolism as diagnosed by neuroimaging.     

Thyroid stimulating hormone testing in ED evaluation of patients with atrial fibrillation and various psychiatric diagnoses

BackgroundPrevious studies of thyroid stimulating hormone (TSH) levels in Emergency Department (ED) patients largely have centered on patients with atrial fibrillation (AF). In our ED patients with AF as well as patients with Psychiatric diagnoses (psych) are screened. The purpose of the present study was to compare TSH levels in the 2 groups. Our hypotheses were that an abnormal TSH and/or AF predicted the need for hospital admission and that TSH is more likely decreased in AF and increased in psych patients.MethodsOur goal in the study was to compare the use of TSH testing in two ED populations, AF vs. psych patients. The study was a cross sectional cohort of AF vs. psych patients who had TSH levels drawn in the ED over a two year period. Our laboratory ranges were used to determine high vs. low TSH. Two chart examiners collected data after a training process. Charts were reviewed extracting demographic data, TSH levels, outcome (admit vs. discharge), history of AF, thyroid disease, psych diagnoses, presence of CHF, diabetes, hypertension. We compared AF vs. Psych groups using chi square and t-tests for parametric data. Odds ratios were calculated for comparisons between the 2 groups. For non-parametric data Mann Whitney U was used. A logistic regression was performed with the outcome of admission vs. discharge to find predictors of hospital admission. Kappa was calculated for inter-rater agreement. An a priori power analysis showed 80% power with 2 groups of 100 with an absolute difference of 20% between the 2 groups.Results252 patients were included, 101 with AF and 152 Psych. Demographics differed in age only with AF patients being older. Mean TSH for AF vs. 2.4 for AF, 2.9 for psych (NS) with no differences in percentages with high or low TSH in the 2 groups. Fifty-three patients had abnormal TSH levels (21%), 27% of AF and 17% of Psych patients (NS). There were significant differences in incidence of CHF, DM, HTN, and tachycardia with more in the AF group (P < 0.001). Significantly more of the psych patients had a history of hypothyroidism (OR 2.28). Our logistic regression showed that taking into account demographics including age, the only predictors of admission were the presence of CHF (aOR 18.6) and having a diagnosis of AF (aOR 4.0).ConclusionThere were no differences in TSH levels between the 2 groups. Twenty-one percent had an abnormal level. CHF and AF predicted hospital admission on regression analysis. Many with these AF or Psych diagnoses had abnormal ED TSH levels that could be useful in diagnosis, maintenance, or continuous treatment for their conditions diagnoses.     

Clinical significance of the atrial fibrillation threshold in patients with paroxysmal atrial fibrillation

AF threshold and the other electrophysiological parameters were measured to quantify atrial vulnerability in patients with paroxysmal atrial fibrillation (PAF, n = 47), and those without AF (non-PAF, n = 25). Stimulations were delivered at the right atrial appendage with a basic cycle length of 500 ms. The PAF group had a significantly larger percentage of maximum atrial fragmentation (%MAF, non-PAF: mean +/- SD = 149 +/- 19%, PAF: 166 +/- 26%, P = 0.009), fragmented atrial activity zone (FAZ, non-PAF: median 0 ms, interquartile range 0-20 ms, PAF: 20 ms, 10-40 ms, P = 0.008). Atrial fibrillation threshold (AF threshold, non-PAF: median 11 mA, interquartile range 6-21 mA, PAF: 5 mA, 3-6 mA, P < 0.001) was smaller in the PAF group than in the non-PAF group. Sensitivity, specificity, and positive predictive value of electrophysiological parameters were as follows, respectively: %MAF (cut off at 150%, 78%, 52%, 76%), FAZ (cut off at 20 ms, 47%, 84%, 85%), AF threshold (cut off at 10 mA, 94%, 60%, 81%). There were no statistically significant differences between the non-PAF and PAF groups in the other parameters (effective refractory period, interatrial conduction time, maximum conduction delay, conduction delay zone, repetitive atrial firing zone, wavelength index), that were not specific for PAF. In conclusion, the AF threshold could be a useful indicator to evaluate atrial vulnerability in patients with AF.     

应用CHADS2评分预测非瓣膜性心房颤动患者左心房/左心耳血栓

目的 探讨非瓣膜性心房颤动(简称房颤)患者CHADS2评分与其左心房/左心耳(LA/LAA)血栓患病率间的关系.方法 回顾性分析187例非瓣膜性房颤患者资料,对其进行CHADS2评分,根据TEE检查结果分为血栓组及非血栓组,分析CHADS2评分与LA/LAA血栓患病率间的关系及各因子在两组中的差异.结果 187例中,27例(27/187,14.44％)确诊为LA/LAA血栓,其中0分者1例(1/47,2.13％),1分者11例(11/82,13.41％),2分者8例(8/33,24.24％),3分者5例(5/17,29.41％),4分者1例(1/6,16.67％),5分者1例(1/2,50.00％);随着CHADS2评分增高,非瓣膜性房颤患者LA/LAA血栓的患病率呈增高趋势(P=0.001).血栓组中伴有充血性心力衰竭者占37.04％(10/27),高于非血栓组(x2 =5.92,P=0.02);而CHADS2评分标准中的其他因子在两组中的差异均无统计学意义(P均＞0.05).结论 随着CHADS2评分增高,非瓣膜性房颤患者LA/LAA血栓的患病率呈增高趋势;充血性心力衰竭是LA/LAA血栓的独立危险因素.     

左心房功能指数评价心房颤动患者射频消融术前后左心房功能

目的应用超声心动图技术检测左心房功能指数(LAFI),以评价阵发性房颤患者经导管射频消融术(RFCA)前后左心房功能变化。方法对30例因阵发性房颤行射频消融术治疗的患者于术前、术后3 d、术后1个月、术后3个月及术后6个月行超声心动图检查。常规测量左心房前后径(LAD),舒张期二尖瓣血流峰值流速及比值(E峰、A峰、E/A),肺静脉血流峰值流速及比值(S峰、D峰、Ar波、S/D)以及左心室流出道速度-时间积分(LVOT-VTI);应用组织多普勒技术(TDI)测量二尖瓣环舒张早期运动速度(Ea)、舒张晚期运动速度(Aa)及比值(Ea/Aa);应用实时三维超声心动图(RT-3DE)测量左心房最大容积(LAVmax)、左心房收缩期前容积(LAVp)及左心房最小容积(LAVmin),计算左心房被动排空分数(LAPEF)、左心房主动排空分数(LAAEF)、左心房排空分数(LAEF)以及左心房功能指数(LAFI)。结果与术前相比,术后3 d LAFI有下降趋势,但差异无统计学意义(P>0.05),A峰及Aa减低(P<0.05);术后1个月,LAFI增高,LAAEF及LAEF增高(P<0.05);术后3个月LAFI增高,LAD及左心房容积减小,LAAEF、LAPEF、LAEF、A峰及Aa增高(P<0.05);术后6个月LAFI增高,LAD及左心房容积减小,LAAEF、LAPEF、LAEF、A峰及Aa增高,S峰增高,D峰减低(P<0.05)。结论 RFCA术后3 d患者左心房功能出现减低趋势;术后1个月患者左心房功能有部分改善,处于缓慢恢复期;术后3个月及6个月患者左心房功能得到全面改善;LAFI是评价房颤患者射频消融术前后左心房功能变化的一项有价值的指标。     

Left atrial appendage occlusion for stroke prevention in patients with atrial fibrillation

The most severe consequence of atrial fibrillation (AF) is a cardioembolic stroke. The incidence of cardioembolic stroke increases significantly in patients with AF. Although warfarin has been the mainstay of the prevention of cardioembolic stroke, there are several limitations to the use of warfarin that hinder its effectiveness. This article provides the historical development of devices that exclude the left atrial appendage, their effectiveness and potential patient selection, as an alternative to warfarin and the novel oral anticoagulation therapy for the prevention of cardioembolic stroke in patients with AF.     

Endothelial function in patients with atrial fibrillation

Abstract

Atrial fibrillation (AF) is the most common heart arrhythmia and is associated with poor outcomes. The adverse effects of AF are mediated through multiple pathways, including endothelial dysfunction, as measured by flow-mediated dilatation. Flow-mediated dilatation has demonstrated endothelial dysfunction in several conditions and is associated with poor outcomes including mortality, yet can be improved with medical therapy. It is thus a useful tool in assessing endothelial function in patients. Endothelial dysfunction is present in patients with AF and is associated with poor outcomes. These patients are generally older and have other co-morbidities such as hypertension, hypercholesterolaemia and diabetes. The precise process by which AF is affiliated with endothelial damage/dysfunction remains elusive. This review explores the endothelial structure, its physiology and how it is affected in patients with AF. It also assesses the utility of flow mediated dilatation as a technique to assess endothelial function in patients with AF.

• Key Messages

• Endothelial function is affected in patients with atrial fibrillation as with other cardiovascular conditions.

• Endothelial dysfunction is associated with poor outcomes such as stroke, myocardial infarction and death, yet is a reversible condition.

• Flow-mediated dilatation is a reliable tool to assess endothelial function in patients with atrial fibrillation.

• Patients with atrial fibrillation should be considered for endothelial function assessment and attempts made to reverse this condition.

     

Managing anticoagulation in patients with atrial fibrillation

Patients with nonvalvular atrial fibrillation have an increased risk of cerebral thromboembolism. Oral anticoagulation therapy, however, provides primary and secondary stroke prevention in these patients. Here, update your knowledge of warfarin initiation, titration, monitoring, and adjustment.