Use of transesophageal echocardiography to guide cardioversion in patients with atrial fibrillation

Transesophageal echocardiography-guided cardioversion after cardiac operations

BACKGROUND

Transesophageal echocardiography (TEE) is often performed during cardiac operations. The need to repeat TEE to exclude left atrial or left atrial appendage thrombus before direct current cardioversion (DCCV) in patients with a recent intraoperative TEE showing no thrombus is unclear. We sought to determine the incidence of and risk factors for new thrombus in patients undergoing TEE-guided DCCV after cardiac operations.

METHODS

We reviewed 817 patients referred for TEE-guided DCCV within 30 days of a cardiac operation and an intraoperative TEE. Patients were excluded if the intraoperative TEE showed thrombus or a surgical left atrial appendage intervention was performed. Univariate logistic regression identified risk factors for thrombus.

RESULTS

The study included 362 patients (71% male) with a mean age of 69 years. Median time from the operation to DCCV was 6 days. Thrombus was present in 13 patients (3.6%) on TEE before cardioversion; DCCV was cancelled in these patients. Heart failure was associated with a significantly higher risk of new thrombus formation (7% vs 2%; odds ratio, 3.26; 95% confidence interval, 1.07 to 9.95). Preoperative atrial arrhythmias, duration of perioperative arrhythmias, level of anticoagulation, and time from operation to DCCV were not significantly associated with thrombus. Thrombus was not associated with 30-day mortality.

CONCLUSIONS

Development of new thrombus in patients with atrial arrhythmias early after cardiac operations is not uncommon, especially in patients with heart failure. Patients at high risk for thromboembolic events should undergo TEE before DCCV, even if a recent intraoperative TEE showed no thrombus.

Acute ischemic stroke following cardioversion in a patient receiving dabigatran

OBJECTIVE

To report a case of acute ischemic stroke following electrical cardioversion in a patient currently anticoagulated with dabigatran 150 mg twice daily.

CASE SUMMARY

A 74-year-old man, who had been adherent with more than 6 weeks of dabigatran 150 mg twice daily therapy, presented with a dense left-sided hemiparesis 72 hours following a repeat electrical cardioversion. Both computed tomography and magnetic resonance angiogram confirmed a right middle cerebral artery infarct. A transesophageal echocardiogram performed after the cerebrovascular accident failed to demonstrate a cardiac source of embolus. The patient previously underwent cardioversion 4 weeks prior with no evidence at that time of thrombus or spontaneous echo contrast on transesophageal echocardiogram.

DISCUSSION

Dabigatran was approved in the United States in late 2010 for the prevention of stroke and systemic embolism in nonvalvular atrial fibrillation. Post hoc data from the phase III trial suggest a low risk of embolism following cardioversion. Since there are no conventional coagulation measures to reliably demonstrate the level of anticoagulation in patients on dabigatran, clinicians must rely solely on patient history when assessing the safety of cardioverting a patient on this medication. Data have suggested increased pro-inflammatory mediators and increased risk of myocardial infarction with oral direct thrombin inhibitors, which may have manifested as a cerebral or carotid artery thrombosis in situ.

CONCLUSION

Novel oral anticoagulants are attractive options for anticoagulation required with cardioversion. Although this case report may not preclude use of dabigatran for this purpose, it illustrates that use of this drug is not without risks. Additional investigation into the pro-inflammatory nature of the oral direct thrombin inhibitors is needed.

Percutaneous left atrial appendage occlusion for stroke prevention in atrial fibrillation: an update

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia encountered in clinical practice. One of its most devastating complications is the development of thromboembolism leading to fatal or disabling stroke. Oral anticoagulation (OAC, warfarin) is the standard treatment for stroke prevention in patients with AF with an increased stroke risk. However, there are several obstacles to long-term OAC therapy, including the risk of serious bleeding, several drug–drug interactions and the need for frequent blood testing. Although newer oral anticoagulants have been developed, these drugs also face issues of major bleeding and non-compliance. Therefore, alternative treatment options for stroke prevention in patients with AF with a high stroke risk are needed. Percutaneous left atrial appendage (LAA) occlusion is an evolving therapy, which should be taken into consideration in those patients with non-valvular AF with a high stroke risk and contraindications for OAC. This article aims to discuss the rationale for LAA closure, the available LAA occlusion devices and their clinical evidence until now. Moreover, we discuss the importance of proper patient selection, the role of various imaging techniques and the need for a more tailored postprocedural antithrombotic therapy.

Management of Atrial Fibrillation

Atrial fibrillation remains the most prevalent cardiac arrhythmia, and its incidence is increasing as the population ages. Common conditions associated with an increased incidence include advanced age, hypertension, heart failure, and valvular heart disease. Patients with atrial fibrillation may complain of palpitations, fatigue, and decreased exercise tolerance or may be completely asymptomatic. Options for treating patients who experience atrial fibrillation include rate-controlling drugs such as digoxin, β-blockers, and calcium channel blockers or a rhythm-controlling strategy with agents such as sodium channel blockers and potassium channel blockers. Atrial fibrillation increases the risk of stroke due to atrial thrombus formation and embolization. Anticoagulation with the vitamin K antagonist, warfarin, remains the most widely prescribed treatment option to decrease stroke risk. Several other antithrombotic agents have recently become available and offer excellent alternatives to warfarin. Catheter ablation can be undertaken as a nonpharmacologic rhythm control option with varying degrees of success depending on duration of atrial fibrillation and follow-up time from the procedure. This review article further describes the management options for patients presenting with atrial fibrillation.

The role of serum C-reactive protein measured by high-sensitive method in thyroid disease

The aim of this study was the evaluation of serum C-reactive protein (CRP) concentration as a marker of the inflammatory state in many different thyroid diseases and its dependence on the stage and duration of disease. We conducted a retrospective analysis of 444 randomly selected patients with different kinds of thyroid disease (106 men and 338 women, ranging 18-72 years of age; mean 56.2 ± 5.0 years; median 52 years). Group 1 (G1) comprised 250 patients with hyperthyroidism. Group 2 (G2) consisted of 72 euthyroid patients. Group 3 (G3) consisted of 122 patients with hypothyroidism. Free T4, free T3, and thyrotropin (TSH) levels were measured using the electrochemiluminescent method. Human serum thyroglobulin autoantibodies (Tg-Abs), thyroperoxidase autoantibodies (TPO-Abs), and autoantibodies against the thyrotropin receptor (TSHR-Abs) levels were measured by radioimmunoassay. The high-sensitive CRP (Hs-CRP) level (reference range <3 mg/L) was determined with a highly sensitive latex-based immunoassay. The mean value of Hs-CRP in G1 was 3.6 ± 2.8 mg/L, in G2 2.5 ± 1.5 mg/L and in G3 5.9 ± 5.8 mg/L. Hs-CRP (in mg/L) medians, interquartile and the total ranges in G1 were 3.0 (2.0 [0.1-21.0] 4.0); in G2: 2.3 [1.8 (0.2-9.2) 3.2]; and in G3: 4.3 [2.2 (0.3-31.5) 7.8]. We found statistically significant differences (Kruskal-Wallis test) in serum Hs-CRP values between G1 and G2 (P = 0.007), G1 and G3 (P = 0.001), G2 and G3 (P < 0.001). In G1, statistically significant correlation was confirmed between Hs-CRP and Tg-Abs (r = -0.22, P = 0.0016), CRP and TPO-Abs (r = -0.26, P < 0.001), and also between Hs-CRP and TSHR-Abs (r = -0.18, P = 0.02). In the remaining cases, differences between Hs-CRP and TSH levels (r = -0.09, P = 0.16) were not statistically significant. In G2, no statistically significant correlation was observed: Hs-CRP and Tg-Abs (r = -0.18, P = 0.13), Hs-CRP and TPO-Abs (r = -0.17, P = 0.15), Hs-CRP and TSH (r = 0.01, P = 0.91), Hs-CRP and TSHR-Abs (r = -0.19, P = 0.17). In G3, a statistically significant correlation was confirmed between Hs-CRP and Tg-Abs (r = 0.22, P = 0.012), Hs-CRP and TSH (r = -0.28, P = 0.001). No statistically significant correlation was observed between Hs-CRP and TPO-Abs (r = 0.20, P = 0.06) and between Hs-CRP and TSHR-Abs (r = -0.23, P = 0.11). Hs-CRP is increased in various types of hypothyroidism. This is particularly relevant in postpartum thyroiditis and in patients after radioiodine treatment. The impact of this situation on human health requires further research, however, one might assume that some types of thyroid disease may lead to systemic inflammatory reactions that are reflected in elevated CRP levels.

Rationale and design of the eXplore the efficacy and safety of once-daily oral riVaroxaban for the prEvention of caRdiovascular events in patients with nonvalvular aTrial fibrillation scheduled for cardioversion trial: A comparison of oral rivaroxaban once daily with dose-adjusted vitamin K antagonists in patients with nonvalvular atrial fibrillation undergoing elective cardioversion

BACKGROUND

Anticoagulation before, during, and after cardioversion is effective in reducing stroke risk in patients with atrial fibrillation.

OBJECTIVE

The objective of this study is to explore the efficacy and safety of rivaroxaban 20 mg once daily (15 mg if creatinine clearance is 30-49 mL/min) compared with dose-adjusted vitamin K antagonists (VKAs; international normalized ratio 2.0-3.0) in patients scheduled for elective cardioversion.

METHODS

This is a prospective, randomized, open-label, parallel group comparison of approximately 1,500 patients from 17 countries with hemodynamically stable nonvalvular atrial fibrillation of >48 hours or unknown duration. Patients will be randomized 2:1 (rivaroxaban:VKA) using 2 cardioversion strategies: the first approach is early cardioversion with the precardioversion anticoagulation goal of 1 to 5 days using rivaroxaban or usual therapy (heparin + VKA). In these patients, transesophageal echocardiography will be encouraged to exclude atrial thrombi. The alternative approach is delayed cardioversion. Rivaroxaban or VKA will be administered for 21 to 56 days before cardioversion. All patients will receive study treatment for 6 weeks postcardioversion. The primary efficacy end point is a composite of all strokes, transient ischemic attacks, noncentral nervous system systemic emboli, myocardial infarctions, and cardiovascular deaths. Each primary end point component will be evaluated separately, and additional composites will be investigated. The principal safety end point is major bleeding.

CLINICAL CONTEXT

This will be the first prospective study of a novel oral anticoagulant in the setting of cardioversion. It will provide important information regarding the use of rivaroxaban in the periods preceding and after cardioversion in a broad patient population.

Dilated cardiomyopathy secondary to hypothyroidism: case report with a review of literatures

To date, it has been well documented that there is a relationship between alterations in thyroid hormones and cardiac dysfunction. We experienced a case of a 36-year-old man with dilated cardiomyopathy (DCM) accompanied by undiagnosed primary hypothyroidism. In the current case, there was a significant improvement in the cardiac function following heart failure management and thyroid hormone replacement. Our case highlights that clinicians should consider the possibility of hypothyroidism as a cause of DCM.

Left Atrial Appendage Closure for Stroke Prevention: Emerging Technologies

Current anticoagulant therapies aimed at stroke prevention in atrial fibrillation (AF) are increasingly challenged by a complex patient population at significant risk of bleeding. Mounting evidence shows that left atrial appendage (LAA) closure is an effective strategy for reducing stroke risk in patients with nonvalvular AF, without the need for anticoagulation. Several approaches and devices have been developed in recent years, each with their own set of advantages and disadvantages. This article reviews these approaches, identifies pertinent aspects, and outlines necessary or ongoing research in establishing LAA closure as a safe and effective approach to stroke risk reduction.

Comparison of high-sensitivity C-reactive protein and fetuin-A levels before and after treatment for subjects with subclinical hyperthyroidism

This study was designed to show the effect of propylthiouracil treatment on sCD40L, high-sensitivity C-reactive protein, and fetuin-A levels on subjects with subclinical hyperthyroidism. After checking sCD40L, high-sensitivity C-reactive protein, and fetuin-A levels of 35 patients with subclinical hyperthyroidism, each was given 50 mg tablets of propylthiouracil three times daily. After 3 months, sCD40L, high-sensitivity C-reactive protein, and fetuin-A levels were then compared to the levels before treatment. Although high-sensitivity C-reactive protein and sCD40L levels were normal in the subclinical hyperthyroidism patients compared to the healthy controls, fetuin-A levels were statistically significantly higher (*p = 0.022). After treatment, fetuin-A levels of subclinical hyperthyroidism patients decreased statistically significantly compared to the levels before treatment (**p = 0.026). sCD40L and high-sensitivity C-reactive protein levels did not have a statistically significant difference compared to the control group and post-propylthiouracil treatment. In subclinical hyperthyroidism patients, high fetuin-A levels before propylthiouracil treatment and decreases in these levels after treatment in cases with subclinical hyperthyroidism indicated the possibility of preventing long-term cardiac complications with propylthiouracil treatment.

The value of diastolic function parameters in the prediction of left atrial appendage thrombus in patients with nonvalvular atrial fibrillation

BACKGROUND

Left ventricular diastolic impairment and consequently elevated filling pressure may contribute to stasis leading to left atrial appendage thrombus (LAAT) in nonvalvular atrial fibrillation (AF). We investigated whether transthoracic echocardiographic parameters can predict LAAT independent of traditional clinical predictors.

METHODS

We conducted a retrospective cohort study of 297 consecutive nonvalvular AF patients who underwent transthoracic echocardiogram followed by a transesophageal echocardiogram within one year. Multivariate logistic regression analysis models were used to determine factors independently associated with LAAT.

RESULTS

Nineteen subjects (6.4%) were demonstrated to have LAAT by transesophageal echocardiography. These patients had higher mean CHADS2 scores [2.6 ± 1.2 vs. 1.9 ± 1.3, P = 0.009], higher E:e' ratios [16.6 ± 6.1 vs. 12.0 ± 5.4, P = 0.001], and lower mean e' velocities [6.5 ± 2.1 cm/sec vs. 9.1 ± 3.2 cm/sec, P = 0.001]. Both E:e' and e' velocity were associated with LAAT formation independent of the CHADS2 score, warfarin therapy, left ventricular ejection fraction (LVEF), and left atrial volume index (LAVI) [E:e' odds-ratio = 1.14 (95% confidence interval = 1.03 - 1.3), P = 0.009; e' velocity odds-ratio = 0.68 (95% confidence interval = 0.5 - 0.9), P = 0.007]. Similarly, diastolic function parameters were independently associated with spontaneous echo contrast.

CONCLUSION

The diastolic function indices E:e' and e' velocity are independently associated with LAAT in nonvalvular AF patients and may help identify patients at risk for LAAT.

Gene polymorphisms and thyroid function in patients with heart failure

We evaluated nuclear factor kappa B {NFkB, rs28362491 [-94ins/delATTG (W/D)]} and angiotensin converting enzyme {ACE; rs1799752 [Ins(I)/Del(D)]} gene polymorphisms and their correlation with thyroid function in patients with heart failure (HF). Peak oxygen uptake (VO(2)) was evaluated (by Weber classification) during a symptom-limited cardiopulmonary exercise test in 194 patients. Thyroid-stimulating hormone, triiodothyronine (T3), thyroxine (T4), and free (F) T3 and FT4 were also measured. According to their cardiovascular (CV) capacity, patients were subdivided into four groups: group A included patients with peak VO(2) >20 ml/kg/min, group B 16-20 ml/kg/min, group C 10-16 ml/kg/min, and group D 6-10 ml/kg/min. Patients were also genotyped for NFkB and ACE genetic variants. T3 was increased and FT3 was decreased for every raise in Weber's classification (p = 0.007 and p = 0.012, respectively). Del carriers had elevated FT3 levels compared with Ins carriers (p = 0.021). Patients with II genotype had elevated T4 levels compared with ID genotype (p = 0.044). Both T4 and FT4 were decreased in D allele carriers (p = 0.007 and p = 0.045, respectively). Thyroid hormones correlated with CV capacity. Associations between the NFkB and ACE gene polymorphisms and thyroid hormones levels were also observed. Further larger studies are required to clarify genes contribution in HF.

Is thyroid-stimulating hormone within the normal reference range a risk factor for atherosclerosis in women?

The relationship between overt hypothyroidism and cardiovascular risk has been well documented and some data also suggest an association between cardiovascular risk and subclinical hypothyroidism. The aim of our study was to investigate, in a large cohort of euthyroid women, the association of thyroid stimulating hormone (TSH) within the normal reference range with cardiovascular risk factors. The study was carried out on 744 women with normal thyroid function (TSH 0.3-4.9 μU/mL). Women with TSH above the median (≥2.1 μU/mL) were more obese, had greater waist girth, were more hypertensive and had higher levels of total cholesterol (TC), serum triglycerides (TG), blood sugar (BG) and lower levels of HDL-cholesterol (HDL-C) than women with TSH below the median. TSH was significantly correlated with body mass index (BMI), waist circumference, BG, TG, TC, HDL-C and hypertension. Multiple backward stepwise regression analysis with age, waist circumference and TSH as independent variables confirmed the strong association of TSH with BG, TG, HDL-C and hypertension. A total of 205 patients (28%) fulfilled the definition criteria of the metabolic syndrome and the prevalence of metabolic syndrome was significantly greater in patients with TSH above than in patients with TSH below the median. Results of logistic analysis, including age and TSH as predictor variables, confirmed the association of TSH with metabolic syndrome.The results of this study suggest that TSH in the upper limits of the reference range (above 2.1 μU/ml) is associated with a less favourable cardiometabolic profile and consequently with a higher risk of developing cardiovascular diseases.

Developmental cues for the maturation of metabolic, electrophysiological and calcium handling properties of human pluripotent stem cell-derived cardiomyocytes

Human pluripotent stem cells (hPSCs), including embryonic and induced pluripotent stem cells, are abundant sources of cardiomyocytes (CMs) for cell replacement therapy and other applications such as disease modeling, drug discovery and cardiotoxicity screening. However, hPSC-derived CMs display immature structural, electrophysiological, calcium-handling and metabolic properties. Here, we review various biological as well as physical and topographical cues that are known to associate with the development of native CMs in vivo to gain insights into the development of strategies for facilitated maturation of hPSC-CMs.

Management of atrial fibrillation in critically ill patients

Atrial fibrillation (AF) is common in ICU patients and is associated with a two- to fivefold increase in mortality. This paper provides a reappraisal of the management of AF with a special focus on critically ill patients with haemodynamic instability. AF can cause hypotension and heart failure with subsequent organ dysfunction. The underlying mechanisms are the loss of atrial contraction and the high ventricular rate. In unstable patients, sinus rhythm must be rapidly restored by synchronised electrical cardioversion (ECV). If pharmacological treatment is indicated, clinicians can choose between the rate control and the rhythm control strategy. The optimal substance should be selected depending on its potential adverse effects. A beta-1 antagonist with a very short half-life (e.g., esmolol) is an advantage for ICU patients because the effect of beta-blockade on cardiovascular stability is unpredictable in those patients. Amiodarone is commonly used in the ICU setting but has potentially severe cardiac and noncardiac side effects. Digoxin controls the ventricular response at rest, but its benefit decreases in the presence of adrenergic stress. Vernakalant converts new-onset AF to sinus rhythm in approximately 50% of patients, but data on its efficacy and safety in critically ill patients are lacking.

Clinical application of enoxaparin

Low-molecular-weight heparins have several important advantages over unfractionated heparin (UFH). Due to a longer plasma half life together with high bioavailability and a linear dose-response relationship, the drugs can be safely and effectively administered in the hospital or ambulatory settings without the need to monitor the anticoagulant effect. Enoxaparin (Lovenox), Aventis Pharma) is a low-molecular-weight heparin which has been studied in a variety of clinical situations. In general surgery the efficacy of enoxaparin to prevent venous thromboembolism is similar to UFH but the tolerability is better. In patients undergoing cancer, orthopedic or vascular surgery the efficacy of enoxaparin is significantly higher with similar rates of bleeding complications. The database for enoxaparin in nonsurgical patients is smaller compared with surgical groups. There is evidence that the efficacy of enoxaparin may be superior to UFH in patients with severe cardiac disease. Efficacy and safety of UFH and enoxaparin are similar for the treatment of deep vein thrombosis. However, enoxaparin can be safely administered by the patients at home which is not possible with UFH. In patients with acute coronary syndromes, enoxaparin has been shown to reduce the rate of deaths and serious cardiac events in comparison with UFH. Furthermore, exonaparin treatment has been shown to be cost-effective, and therefore is the therapy of choice in this setting. In addition, enoxaparin has been shown to be a safe and effective alternative to the combination of UFH and phenprocoumone therapy in patients undergoing electrical cardioversion for atrial fibrillation.

Transesophageal echocardiography: a complementary view of the heart

Transesophageal echocardiography has been widely used as a diagnostic tool during the past two decades to detect cardiac abnormalities that are not visible or poorly visible with transthoracic echocardiography. At present, transesophageal echocardiography is a cornerstone of modern diagnosis of several cardiac diseases, providing diagnostic, prognostic and therapeutic information. In this review, the present status of transesophageal echocardiography not only as a diagnostic tool, underlining its effects on clinical decision making, but also as a monitoring adjunct for many interventional cardiac procedures is examined.

Atrial fibrillation

Atrial fibrillation is the most common arrhythmia affecting patients today. Disease prevalence is increasing at an alarming rate worldwide, and is associated with often catastrophic and costly consequences, including heart failure, syncope, dementia, and stroke. Therapies including anticoagulants, anti-arrhythmic medications, devices, and non-pharmacologic procedures in the last 30 years have improved patients' functionality with the disease. Nonetheless, it remains imperative that further research into AF epidemiology, genetics, detection, and treatments continues to push forward rapidly as the worldwide population ages dramatically over the next 20 years.

Resolution of left atrial appendage thrombus with apixaban

Left atrial appendage (LAA) thrombosis is an important cause of cardiogenic cerebral thromboembolism. Apixaban is a member of the class of novel oral anticoagulants (NOAC) and is superior to warfarin in preventing stroke or systemic embolism, causes less bleeding, and results in lower mortality in patients with atrial fibrillation. There are few reports of resolution of LAA thrombus with other NOAC. We present a 72-year-old male patient with persistent atrial fibrillation associated with left atrial thrombus. Sixteen days of apixaban treatment showed complete thrombus resolution. In this study, soluble fibrin and D-dimer levels decreased without prolongation of international normalized ratio (INR) and activated partial thromboplastin time (APTT).

A cross-sectional study of subclinical and clinical thyroid disorders in women with microscopic colitis compared to controls

BACKGROUND AND AIMS. Microscopic colitis (MC), predominantly affecting women, is associated with thyroid disorders, although purely defined of which type, or compared with controls. Its association with subclinical thyroid disorders, and related increased risk of cardiovascular diseases, has never been examined. The aim was to examine the prevalence of autoantibodies and subclinical and clinical thyroid dysfunction in female patients with MC compared with controls. METHODS. Women younger than 73 years old with biopsy-verified MC from the Department of Gastroenterology in Skåne, during 2002-2010, were invited. Out of 240 identified, 133 were finally included. A questionnaire about medical history was completed and blood samples were collected. Serum was analyzed for free thyroxin and triiodothyronine, thyroid-stimulating hormone and anti-thyroid peroxidase (anti-TPO) antibodies. A population-based group of 737 women served as controls. RESULT. The prevalence of thyroid disorders in patients was higher compared to controls [odds ratio (OR) = 2.98, 95% confidence interval (CI) = 1.78-4.99], but the prevalence of subclinical disorders was not different (OR = 1.18, 95% CI = 0.48-2.85). Anti-TPO antibodies were present in 10.6% of MC patients and 18.6% of controls. Twenty-five MC patients had hypothyroidism: 15 with Hashimoto's hypothyroidism, 6 with completed treatment of thyrotoxicosis and 4 with completed surgery after nontoxic goiter. CONCLUSION. Thyroid disorders, autoimmune hypothyroidism being most frequent, are more prevalent in patients with MC than in controls, whereas the prevalence of subclinical thyroid disorders in MC patients does not differ significantly from controls.

Efficacy of the CHADS₂ scoring system to assess left atrial thrombogenic milieu risk before cardioversion of non-valvular atrial fibrillation

The CHADS₂ scoring system was found to be a good predictor for risk stratification of stroke in patients with atrial fibrillation. The effectiveness of this scoring system in assessing thrombogenic milieu before direct-current cardioversion has not yet fully been established on a large scale. In this study, data from 2,369 consecutive patients in whom transesophageal echocardiography was performed for screening before direct-current cardioversion from 1999 to 2008 were analyzed. Left atrial (LA) or LA appendage (LAA) thrombogenic milieu (spontaneous echo contrast, sludge, and thrombus) was investigated. The results were correlated with CHADS₂ score findings. The mean age was 66 ± 13 years, and the ratio of men to women was 2.2:1. CHADS₂ scores of 0, 1, 2, 3, 4, 5 and 6 were present in 11%, 25%, 30%, 22%, 8%, 3%, and 1% of the studies, respectively. The prevalence of LA or LAA sludge or thrombus increased with increasing CHADS₂ scores (2.3%, 7%, 8.5%, 9.9%, 12.3%, and 14.1% for scores of 0, 1, 2, 3, 4, and 5 or 6, respectively, p = 0.01). In a multivariate model, an ejection fraction ≤20% was the best predictor of LA or LAA sludge or thrombus (odds ratio 2.99, p <0.001). In conclusion, transesophageal echocardiographic markers of thrombogenic milieu were highly correlated with increasing CHADS₂ scores in patients who underwent transesophageal echocardiography-guided cardioversion. Giving more value to echocardiographic findings, such as the left ventricular ejection fraction, and its different levels (especially an ejection fraction ≤20%) might improve the precision of the CHADS₂ scoring scheme to predict thrombogenic milieu in the left atrium or LAA as a surrogate to cardioembolic risk in patients with atrial fibrillation.

[Atrial fibrillation in the ICU. Distinct entity--special treatment?]

Atrial fibrillation (AF) is the single most frequent arrhythmia in the intensive care unit, occurring among 44-61 % of all patients with arrhythmias in the intensive care unit. The success rate of electrical cardioversion (DC-CV) early after surgery is as low as 10-35 % in postoperative AF but 6 weeks after discharge 90 % are in sinus rhythm (SR). Several guidelines recommend rate control in these patients and rate control with β-blockers and calcium channel blockers is not inferior with respect to outcome, 6 min walk test, and quality of life. DC-CV is recommended in unstable and heart failure patients. The term resistant AF is suggested for that distinct situation of AF not amenable to cardioversion solely in the acute phase of critical illness.

Supraventricular and ventricular arrhythmias

Cardiac arrhythmias comprise of a heterogeneous group of disorders which manifest in a wide range of clinical presentations. They can be associated with underlying cardiac disease and portend a grave prognosis, with some arrhythmias being rapidly fatal. Other arrhythmias, however are relatively benign and can be asymptomatic or may be a mere inconvenience for the patient. All primary care physicians can expect to encounter some forms of arrhythmias during the course of their practice. This review article provides a brief overview of the commonly seen tachyarrhythmias for the general practitioner and provides relevant updates on the recent developments in our understanding of their mechanisms and management.

Low stroke risk after elective cardioversion of atrial fibrillation: an analysis of the Flec-SL trial

BACKGROUND

Current recommendations for anticoagulation management during cardioversion are largely based on historical data and expert consensus.

METHODS AND RESULTS

To characterize current practice of anticoagulation during and after elective cardioversion for AF and the risk of stroke and bleeding events, all patients enrolled into the Flec-SL trial were analyzed for stroke/transient ischemic attack and major bleeds after cardioversion. Flec-SL (ISRCTN62728743, NCT00215774) enrolled 635 patients (mean age 63.7 ± 10.9, 66% male). 629 (99.1%) patients received periprocedural anticoagulation, 556 (87.6%) were adequately anticoagulated following current recommendations. 202 (31.8%) patients underwent transesophageal echocardiography-guided cardioversion. Electrical cardioversion was used in 508 patients (80.0%), pharmacological cardioversion in 127 (20%). Six patients suffered from stroke (n = 5) or transient ischemic attack (3 TIAs in 1 patient, event rate 0.9%, 95% CI 0.4-2.1), five others from major bleeds (event rate 0.8%, 95% CI 0.3-1.9), consistent with the low reported event rates in prior studies. Three strokes occurred in the first 5 days after cardioversion. Events were independent of type of cardioversion or the use of TEE to exclude thrombi.

CONCLUSION

Strokes are rare in this large, prospectively followed cohort of patients undergoing cardioversion for AF and receiving antithrombotic therapy following local routine. These results support adherence to current recommendations for anticoagulation during cardioversion of AF.

CUTE-CV: a prospective study of enhanced left atrial appendage visualization with microbubble contrast agent use during transesophageal echocardiography guided cardioversion

OBJECTIVES

The aim of our study was to demonstrate that the use of contrast microbubbles during transesophageal echocardiography (TEE) guided cardioversion will improve interpretation of the TEE images.

BACKGROUND

TEE-guided cardioversion of atrial flutter or fibrillation (AF) is a safe and proven method to restore sinus rhythm. However, artifacts and dense spontaneous echo contrast in the left atrial appendage (LAA) can sometimes decrease the level of confidence in excluding the presence of thrombus.

METHODS

One hundred patients referred for TEE-guided cardioversion were prospectively enrolled and microbubble contrast agent (DEFINITY) was administered after the clinical decision had been made regarding suitability for cardioversion. Noncontrast and contrast images were compared during subsequent offline analysis.

RESULTS

LAA dimensions and contractility indices were higher, artifacts were significantly differentiated, previously unsuspected LAA filling defects were identified, and the level of confidence in excluding thrombus was enhanced in the contrast images when compared to the noncontrast images. After 4 months follow-up, 1 stroke-associated death occurred in a patient who had LAA thrombus recognized only by contrast. Left atrial appendage visualization is enhanced with microbubble contrast agent use during transesophageal echocardiography guided cardioversion and is useful in identification of intracardiac thrombus.

Role of the new target specific oral anticoagulants in the management of anticoagulation for cardioversion and atrial fibrillation ablation

Atrial fibrillation (AF) is the most prevalent arrhythmia in United States. Patients with AF are at increased risk of thromboembolic events. This risk is even higher with cardioversion and ablation, especially during periprocedural period. Conventional approaches using heparin and warfarin have been successfully studied to mitigate thromboembolic risk. However, these approaches are with certain inherent limitations. The advent of new target specific oral anticoagulants (TSOAs) may overcome some of the impediments of conventional therapies and provide an alternative for anticoagulation for cardioversion and AF ablation. We will review the role of the new TSOAs in the current anticoagulation strategies to reduce the risk of thromboembolic events associated with cardioversion and AF ablation.

Thyroid hormone and cardiovascular system: from basic concepts to clinical application

Experimental and clinical findings strongly support the concept that thyroid hormone (TH) plays a fundamental role in the cardiovascular (CV) homeostasis. CV diseases represent a major public health care and economic problem being one of the principal causes of morbidity, mortality and hospitalization. In particular, chronic heart failure (HF) is one of the most common reasons for general practitioners consultations in people >65-70 years old. TH derangement may have a key role in the evolution process of HF. In HF, the main and earlier alteration of the thyroid function is referred to as "low-T3" syndrome characterized by the reduction in serum total T3 and free T3 with normal levels of thyroxine (T4) and thyrotropin (TSH). This syndrome may affect till one-third of advanced HF patients. The main goal of this mini-review is to examine the main pathophysiological and clinical links between an altered thyroid metabolism and CV diseases, namely HF during progression of disease from organ specific to systemic disorder.

Percutaneous closure of the left atrial appendage for thromboembolic prevention in atrial fibrillation

Atrial fibrillation is a common arrhythmia in clinical practice. It is associated with high morbidity and mortality due to its thromboembolic potential, which makes thromboembolic prevention particularly important. Warfarin has been the first-line therapy for this purpose, but it has various limitations and is often contraindicated or underutilized. The fact that thrombi are frequently located in the left atrial appendage in atrial fibrillation led to the development of percutaneous closure for thromboembolic prevention. This article examines the current evidence on percutaneous closure of the left atrial appendage by reviewing the results of the numerous clinical trials on the technique.

[Surgical closure of the left atrial appendage in patients with atrial fibrillation. Indications, techniques and results]

Cardiac embolisation in patients with atrial fibrillation accounts for the most serious complication of cerebral infarction. The left atrial appendage resembles the origin of these cardiac emboli in the majority of cases, although other anatomical areas of the left atrium might also be prerequisites for thrombus formation. Surgical closure of the left atrial appendage during an ablation therapy incorporates the theoretical possibility of reducing the rate of cardiac cerebral infarction. In order to achieve closure, different surgical strategies exist: either exclusion by over-sewing or snaring or excision by using scissors or a stapling device. All therapies incorporate pros and cons. One of the major complications and most feared side-effect is the recanalisation of a formerly closed left atrial appendage, especially in a thrombus filled left atrial appendage cavity. But also reopening of the formerly closed orificium and still existing remnants with communication to the left atrium might stand for an increased risk. Due to the good results of left atrial appendage excision, this surgical therapy at the moment presents the surgical gold standard, as this therapy is recommended in the updated ESC guidelines for the management of atrial fibrillation. If excision of the left atrial appendage will reduce the risk of cardiac embolisation needs to be examined in large prospective-randomized trials with a controlled systemic follow-up. So far, excision of the left atrial appendage as an alternative to oral anticoagulation, especially in patients with atrial fibrillation, is not recommended.

Elevated thyroid stimulating hormone levels are associated with metabolic syndrome in euthyroid young women

BACKGROUND/AIMS

The existence of an association between thyrotropin (thyroid stimulating hormone, TSH) levels and metabolic derangement in euthyroid subjects is controversial. We examined the association between high normal TSH levels and metabolic syndrome in healthy young women.

METHODS

The study recruited 2,760 young female volunteers (age, 18 to 39 years) with TSH levels in the normal range (0.3 to 4.5 mU/L). We defined metabolic syndrome using the 2007 International Diabetes Federation criteria. Using a TSH level of 2.5 mU/L as an upper reference limit, as recommended by the National Academy of Clinical Biochemistry, we divided the subjects into high-(n = 453) and low-TSH groups (n = 2,307).

RESULTS

The prevalence of metabolic syndrome was significantly higher in the high-TSH group than in the low-TSH group (7.5% vs. 4.8%, p = 0.016). Central obesity (22.3% vs. 17.3%, p = 0.012) and hypertriglyceridemia (8.0% vs. 4.2%, p = 0.0007) were significantly more frequent in the high-TSH group than in the low-TSH group. Waist circumference, systolic and diastolic blood pressure, and triglycerides were significantly associated with the TSH level after adjusting for age and body mass index (BMI). Subjects in the high-TSH group had a 2-fold greater risk of metabolic syndrome than subjects in the low-TSH group after adjusting for age and BMI (odds ratio, 1.9; 95% confidence interval, 1.1 to 3.2).

CONCLUSIONS

Healthy young women with TSH levels > 2.5 mU/L should be assessed for the presence of metabolic syndrome, even if their TSH levels are in the normal range.

Contrast enhanced transesophageal echocardiography in patients with atrial fibrillation referred to electrical cardioversion improves atrial thrombus detection and may reduce associated thromboembolic events

Aims

Transesophageal echocardiography (TEE) is the gold standard for the detection of thrombi in patients with atrial fibrillation (AF) before undergoing early electrical cardioversion (CV). However, TEE generates inconclusive results in a considerable number of patients. This study investigated the influence of contrast enhancement on interpretability of TEE for the detection of left atrial (LA) thrombi compared to conventional TEE and assessed, whether there are differences in the rate of thromboembolic events after electrical cardioversion.

Methods

Of 180 patients with AF (51 females, 65.2±13 years) who were referred to CV, 90 were examined with native imaging and contrast enhancement within the same examination (group 1), and 90 were examined with native TEE alone and served as control (group 2). Cineloops of the multiplane examination of the LA and LA appendage (LAA) were stored digitally before and, in group 1, after intravenous bolus application of a transpulmonary contrast agent. Images of group 1 were assessed offline and the diagnosis of LA thrombi was made semi-quantitatively: 1= thrombus present; 2=inconclusive result; 3=no thrombus. The presence of spontaneous echocontrast (SEC) was registered and flow velocity in the LA appendage (LAA-flow) was measured. All patients in whom CV was performed were followed up for 1 year or until relapse of AF. CV related adverse events were defined as any thromboembolic event within 1 week after CV.

Results

No serious adverse events occurred during TEE and contrast enhanced imaging. In group 1 atrial thrombi were diagnosed in 14 (15.6%) during native and in 10 (11.1%) patients during contrast enhanced imaging (p<0.001). Of the 10 patients with thrombi in the contrast TEE group, 7 revealed a decreased LAA-flow (≤0,3m/s) and 8 showed moderate or marked SEC. Uncertain results were significantly more common during native imaging than with contrast enhanced TEE (16 vs. 5 patients, p<0.01). Thrombi could definitely be excluded in 60 (66.7%) during conventional and in 75 patients (83.3%) during contrast enhanced TEE (p<0.01). CV was performed subsequently after exclusion of thrombi and at the discretion of the investigator. In group 1, 74 patients (82.2%) were cardioverted and no patient suffered a CV related complication (p=0.084). In group 2, 76 patients (84.4%) underwent CV, of whom 3 suffered a thromboembolic complication after CV (2 strokes, 1 peripheral embolism).

Conclusion

In patients with AF planned for CV contrast enhancement renders TEE images more interpretable, facilitates the exclusion of atrial thrombi and may reduce the rate of embolic adverse events.

External validation of a novel transthoracic echocardiographic tool in predicting left atrial appendage thrombus formation in patients with nonvalvular atrial fibrillation

BACKGROUND

A recent study demonstrated that in patients with nonvalvular atrial fibrillation (AF), a ratio of left ventricular ejection fraction (LVEF) to the left atrial volume index (LAVI) of <1.5 has 100% sensitivity for detecting left atrial appendage (LAA) thrombus. We sought to validate this prediction tool in an external cohort.

METHODS

We conducted a cohort study of consecutive AF patients who underwent transoesophageal echocardiogram (TEE) to 'rule-out' LAA thrombus and had a prior transthoracic echocardiogram (TTE). The LAVI and LVEF were measured to calculate LVEF/LAVI ratio. The sensitivity and specificity of LVEF/LAVI <1.5 were calculated.

RESULTS

Among 215 subjects, 19 (8.8%) had LAA thrombus and also had a higher mean CHADS2 score (2.5 vs. 1.9, P = 0.04), lower mean LVEF (24 vs. 44%, P < 0.001), higher mean LAVI (44 mL/m2 vs. 30 mL/m2, P < 0.001), and higher prevalence of cardiac failure (79 vs. 52%, P = 0.02). The LVEF and LAVI were found to be independent predictors of LAA thrombus (P < 0.05). The LVEF/LAVI ratio diagnosed LAA thrombus with an area under the curve = 0.83 by the receiver operator characteristics curve analysis (P < 0.001). All 19 (100%) subjects with LAA thrombus had LVEF/LAVI <1.5 vs. 87 (44%) among those without LAA thrombus (P < 0.001). The sensitivity and specificity of LVEF/LAVI <1.5 were 100 and 55.6%, respectively.

CONCLUSION

This investigation validates a simple TTE prediction rule to exclude the diagnosis of LAA thrombus, which may obviate the need for pre-cardioversion TEE in selected patients with nonvalvular AF.

Right atrial appendage thrombus found in a patient in normal sinus rhythm with normal right ventricular systolic function

A 79-year-old woman underwent transesophageal echocardiography to evaluate the severity of her mitral regurgitation prior to urgent bypass. Evaluation of the right-sided chambers was notable for a mass in the right atrial appendage (RAA). Surgical excision and pathologic examination proved this to be a thrombus. This is the first reported case of a RAA thrombus in a patient with normal sinus rhythm and normal right ventricular (RV) function. It illustrates that complete transesophageal studies may sometimes demonstrate incidental findings, and that right atrial thrombus can (rarely) be found in patients in sinus rhythm with normal RV function.