Avidity-based bright and photostable light-up aptamers for single-molecule mRNA imaging.

Fluorescent light-up aptamers (FLAPs) have emerged as valuable tools to visualize RNAs, but are mostly limited by their poor brightness, low photostability, and high fluorescence background in live cells. Exploiting the avidity concept, here we present two of the brightest FLAPs with the strongest aptamer-dye interaction, high fluorogenicity, and remarkable photostability. They consist of dimeric fluorophore-binding aptamers (biRhoBAST and biSiRA) embedded in an RNA scaffold and their bivalent fluorophore ligands (bivalent tetramethylrhodamine TMR2 and silicon rhodamine SiR2). Red fluorescent biRhoBAST-TMR2 and near-infrared fluorescent biSiRA-SiR2 are orthogonal to each other, facilitating simultaneous visualization of two different RNA species in live cells. One copy of biRhoBAST allows for simple and robust mRNA imaging with strikingly higher signal-to-background ratios than other FLAPs. Moreover, eight biRhoBAST repeats enable single-molecule mRNA imaging and tracking with minimal perturbation of their localization, translation, and degradation, demonstrating the potential of avidity-enhanced FLAPs for imaging RNA dynamics.

Pulmonary arterial wall thickness increased in Behçet's disease patients with major organ involvement: Is it a sign of severity?

OBJECTIVES: Behçet's disease (BD) is a unique systemic vasculitis mainly involving veins, in contrast to other vasculitides. Prior studies have shown that pulmonary arteries (PAs) have a similar structure to systemic veins. In this study we aimed to assess PA wall thickness by transthoracic echocardiography (TTE) in BD patients compared with healthy controls (HCs) and patients with non-inflammatory pulmonary embolism (NIPE). METHODS: Patients with BD (n = 77) and NIPE (n = 33) and HCs (n = 57) were studied. PA wall thickness was measured from the mid-portion of the main PA with TTE by two cardiologists blinded to cases. RESULTS: PA wall thickness was significantly lower in HCs [3.6 mm (s.d. 0.3)] compared with NIPE [4.4 mm (s.d. 0.5)] and BD [4.4 mm (s.d. 0.6)] (P < 0.001 for both). PA wall thickness was similar between BD and NIPE (P = 0.6). Among patients with BD, PA wall thickness was significantly higher in patients with major organ involvement compared with mucocutaneous limited disease [4.7 mm (s.d. 0.4) vs 3.7 (0.4), P < 0.001], HCs and NIPE (P < 0.001 and P = 0.006, respectively). PA wall thickness was comparable between patients with vascular and non-vascular major organ involvement [4.6 mm (s.d. 0.5) vs 4.7 (0.3), P = 0.3]. CONCLUSION: We observed that PA wall thickness was significantly higher in BD with major organ involvement compared with patients with only mucocutaneous limited disease, HCs and NIPE. These results suggest that increased PA wall thickness may be a sign of severe disease with major organ involvement in BD.

Evaluation of Arterial Stiffness and Subfoveal Choroidal Thickness in Patients with Coronary Slow Flow.

Background: Coronary slow flow may not only affect the coronary arteries, but it may also be a vascular problem affecting the rest of the arterial system. Objective: The aim of this study was to determine peripheral arterial stiffness and the thickness of the choroid layer in patients with slow coronary flow. Methods: Fifty consecutive patients (age, 54.3 ± 11.4 years, 38 male) with coronary slow flow and 25 consecutive patients (age, 50.5 ± 9.9 years, 16 male) with normal coronary arteries both documented by coronary angiography were included. Arterial stiffness parameters were measured noninvasively using a Mobil-O-Graph arteriography system. The choroidal thickness was assessed using the enhanced depth imaging optical coherence tomography method. Results: The patients with coronary slow flow had significantly higher peripheral systolic blood pressure, peripheral pulse pressure, central pulse pressure, and pulse wave velocity (PWV) and significantly thinner choroidal thickness compared to the controls. Thrombolysis in myocardial infarction frame count was positively correlated with PWV (r: 0.237, p = 0.041) and negatively correlated with choroidal thickness (r: -0.249, p = 0.031). There was also a negative correlation between PWV and mean choroidal thickness (r: -0.565, p < 0.001). Linear regression analysis showed that coronary slow flow was an independent predictor of both PWV and choroidal thickness when adjusted by age and sex. Conclusions: The acceleration of average peripheral arterial PWV with a thinning of choroidal thickness in patients with coronary slow flow may support the idea that this phenomenon may be a coronary presentation of a systemic microvascular disorder.

Is there any relation between arterial stiffness and insomnia? A challenging question.

PURPOSE: Insomnia is a common sleep disorder which has high comorbidity with a number of cardiovascular diseases (CVD). As a possible risk factor for the CVDs, arterial stiffness may be assessed non-invasively by pulse wave velocity (PWV) and augmentation index (AI). The aim of this study was to evaluate any relation between insomnia and arterial stiffness. METHODS: Patients with insomnia were included in the study after the exclusion of other sleep disorders by polysomnography. Sleep quality and the degree of insomnia symptoms were evaluated by the Pittsburgh sleep quality index (PSQI) and insomnia severity index (ISI), respectively. PWV and AI were assessed by Mobil-O-Graph arteriograph system. RESULTS: Consecutive patients with insomnia (n = 72, 56 women, mean age 55.8 ± 9.1 years) were included. Patients were grouped as those with severe ISI scores (22-28) and those with mild to moderate ISI scores (8-21). Despite no significant difference in characteristics and clinical data, patients with severe ISI scores had significantly higher total PSQI scores and NREM-2 with significantly lower REM duration. They also had significantly higher systolic blood pressure, mean blood pressure, pulse pressure, PWV, and AI compared to patients with mild and moderate ISI scores. Correlation analysis revealed that PWV and AI were significantly correlated with the ISI score and PSQI score. CONCLUSION: There is a close relation between arterial stiffness and insomnia suggesting a risk for CVD in patients with insomnia.

Neurogenic stunned myocardium in acute ischemic stroke.

BACKGROUND AND PURPOSE: Neurogenic myocardial injury occurs as a result of dysregulation of autonomic nervous system. The aim of this study was to explore the frequency of elevated troponin and dynamic ST segment/T wave changes and their relation with left ventricular (LV) systolic functions in acute ischemic stroke patients. METHODS: One hundred and twenty-five patients (mean age: 65.1±15.2years, 76 male) presenting with acute ischemic stroke were consecutively included. 12-lead electrocardiogram was taken to assess dynamic ST segment/T wave changes, conventional transthoracic echocardiography to determine LV ejection fraction (LVEF). High-sensitive cardiac troponin I (hs-cTnI) level>0.04ng/mL was accepted as elevated. RESULTS: Twenty-seven patients (21.6%) had elevated hs-cTnI and 60 patients (48%) had dynamic ST segment/T wave changes. The stroke patients with elevated hs-cTnI had significantly higher NT-proBNP values (2302±3450pg/mL vs 799±2075pg/mL p<0.001) and higher frequency of ST segment/T wave changes (85.2% vs 37.8% p<0.001), and lower LVEF (52.2±13.6% vs 61.0±8.5% p=0.002) compared to patients with normal troponin levels. The patients with ST segment/T wave changes had significantly higher frequencies of hyper-lipidemia (31.7% vs 15.4% p=0.031) and coronary artery disease (CAD) (43.3% vs 13.8% p<0.001), hs-cTnI (0.19±0.55ng/mL vs 0.02±0.01ng/mL p<0.001) and NT-proBNP levels (1430±2564pg/mL vs 842±2425pg/mL p=0.016), and lower LVEF (56.1±11.7% vs 61.9±8.3% p=0.009). Linear regression analysis revealed presence of CAD, but not ST segment/T wave changes as an independent predictor of hs-cTnI (p=0.034). LVEF was independently associated with hs-cTnI (p=0.003) and presence of CAD (p=0.009) when adjusted by age, sex and presence of ST segment/T wave changes. CONCLUSION: Troponin elevation and ST segment/T wave changes occurring in patients suffering acute ischemic stroke, especially in those with CAD, may be a sign of neurogenic stunned myocardium.

Is there an increased cardiovascular risk in patients with prolactinoma? A challenging question.

PURPOSE: Epicardial adipose tissue thickness (EATT) is considered to be a surrogate for visceral fat and a novel cardiovascular risk indicator. Hyperprolactinemia has been shown to be associated with increased cardiovascular risk. The aim was to evaluate the association between EATT, carotid intima media thickness (CIMT), and cardiac functions in patients with prolactinoma. METHODS: Patients with the diagnosis of prolactinoma were included. The control group consisted of healthy age matched individuals with normal prolactin levels. Prolactin, fasting blood glucose (FBG), insulin, hemoglobin A1c (HbA1c), alanine aminotransferase (ALT), total cholesterol, triglycerides, and high (HDL) and low density lipoprotein (LDL) cholesterol were measured. EATT, CIMT, cardiac systolic, and diastolic functions were determined using echocardiography. RESULTS: We evaluated 67 patients with prolactinoma (aged 40.7 ± 11.9 years, F/M: 51/16) and 57 controls (aged 42.5 ± 7.4 years, F/M: 36/21). Of the 67 patients, 24 had normal prolactin levels. FBG level was higher in prolactinoma patients than in controls. Patients and controls had similar HbA1c, HOMA-IR, ALT, total, HDL, LDL cholesterol, and triglycerides levels, and similar cardiac systolic and diastolic functions. Prolactinoma patients had greater EATT (3.0 ± 0.5 mm vs. 2.6 ± 0.4 mm, p < 0.001) and CIMT (0.57 ± 0.08 mm vs. 0.52 ± 0.04 mm, p = 0.03) than controls. EATT was correlated with body mass index, FBG, HbA1c, and triglyceride levels. CONCLUSIONS: EATT and CIMT were greater in patients with prolactinoma, although they had normal cardiac systolic and diastolic functions.

Ventricular and atrial functions assessed by speckle-tracking echocardiography in patients with human immunodeficiency virus.

PURPOSE: Antiretroviral therapy (ART) has dramatically changed the clinical manifestation of human immunodeficiency virus (HIV) associated cardiomyopathy from severe left ventricular (LV) systolic dysfunction to a pattern of subclinical cardiac dysfunction. The aim of this study was to evaluate by speckle tracking echocardiography (STE) LV, right ventricular (RV), and biatrial functions in HIV-infected patients under different ART combinations. METHODS: We consecutively included 128 HIV-infected patients (mean age 44.2 ± 10.1 years, 110 males) and 100 controls (mean age 42.1 ± 9.4 years, 83 males). Ventricular and atrial functions were assessed by both conventional and STE. RESULTS: Although there was not any significant difference in conventional echocardiographic variables, HIV-infected patients had significantly lower LV global longitudinal strain (GLS), RV GLS, left atrial (LA) reservoir and conduit strain, and right atrial conduit strain. HIV patients receiving integrase strand transfer inhibitors and protease inhibitors (PI) had significantly lower LV GLS and LA conduit strain, while patients receiving non-nucleoside reverse transcriptase inhibitors and PI had significantly lower RV GLS than controls. CD4 count at the time of echocardiography was strongly correlated with LV GLS (r = .619, P < .001) and RV GLS (r = .606, P < .001). CONCLUSION: Biventricular and atrial functions are subclinically impaired in HIV-infected patients. ART regimen may also affect myocardial functions.

The evaluation of right ventricle dyssynchrony by speckle tracking echocardiography in systemic sclerosis patients.

PURPOSE: Systemic sclerosis (SSc) is associated with right ventricle (RV) remodeling and dysfunction. The primary aim of this study was to evaluate RV dyssynchrony (RV-Dys) in SSc patients using two-dimensional speckle tracking echocardiography (2D-STE). METHODS: Fifty-five SSc patients with functional class I-II and 45 healthy controls were consecutively included and underwent 2D-STE. RV-Dys was defined as the standard deviation of time to peak strain of mid and basal segments of RV free wall and interventricular septum. SSc group was further classified according to the presence of pulmonary arterial hypertension (PAH). Patients with tricuspid regurgitant velocity >2.8 m/s with additional echocardiographic PAH signs were defined as SSc PAH (+). RESULTS: SSc patients had lower RV longitudinal strain (RV-LS) (-17.6 ± 4.6% vs. -20.8 ± 2.8%, p < 0.001) and greater RV-Dys (49.9 ± 25.4 ms vs 24.3 ± 11.8 ms, p = 0.006) than controls despite no significant difference in conventional echocardiographic variables regarding RV function. Although SSc PAH(+) patients had lower RV-LS and higher RV-Dys than SSc PAH(-) patients, the differences were not statistically significant. The only independent predictor of RV-Dys was RV-LS (ß:-0.324 [-3.89- -0.45]; p = 0.014). CONCLUSION: SSc patients had not only reduced RV-LS but also impaired RV synchronicity even as conventional echocardiographic variables were preserved.

A Color-Shifting Near-Infrared Fluorescent Aptamer-Fluorophore Module for Live-Cell RNA Imaging.

Fluorescent light-up RNA aptamers (FLAPs) have become promising tools for visualizing RNAs in living cells. Specific binding of FLAPs to their non-fluorescent cognate ligands results in a dramatic fluorescence increase, thereby allowing RNA imaging. Here, we present a color-shifting aptamer-fluorophore system, where the free dye is cyan fluorescent and the aptamer-dye complex is near-infrared (NIR) fluorescent. Unlike other reported FLAPs, this system enables ratiometric RNA imaging. To design the color-shifting system, we synthesized a series of environmentally sensitive benzopyrylium-coumarin hybrid fluorophores which exist in equilibrium between a cyan fluorescent spirocyclic form and a NIR fluorescent zwitterionic form. As an RNA tag, we evolved a 38-nucleotide aptamer that selectively binds the zwitterionic forms with nanomolar affinity. We used this system as a light-up RNA marker to image mRNAs in the NIR region and demonstrated its utility in ratiometric analysis of target RNAs expressed at different levels in single cells.

SRB-2: a promiscuous rainbow aptamer for live-cell RNA imaging.

The SRB-2 aptamer originally selected against sulforhodamine B is shown here to promiscuously bind to various dyes with different colors. Binding of SRB-2 to these dyes results in either fluorescence increase or decrease, making them attractive for fluorescence microscopy and biological assays. By systematically varying fluorophore structural elements and measuring dissociation constants, the principles of fluorophore recognition by SRB-2 were analyzed. The obtained structure-activity relationships allowed us to rationally design a novel, bright, orange fluorescent turn-on probe (TMR-DN) with low background fluorescence, enabling no-wash live-cell RNA imaging. This new probe improved the signal-to-background ratio of fluorescence images by one order of magnitude over best previously known probe for this aptamer. The utility of TMR-DN is demonstrated by imaging ribosomal and messenger RNAs, allowing the observation of distinct localization patterns in bacteria and mammalian cells. The SRB-2 / TMR-DN system is found to be orthogonal to the Spinach/DFHBI and MG/Malachite green aptamer/dye systems.

Evaluation of right ventricular dyssynchrony in patients with acute inferior myocardial infarction and its relation with mortality.

PURPOSE: The aim of this study was to evaluate right ventricle (RV) dyssynchrony and its relation with mortality using speckle-tracking echocardiography (STE) in patients with acute inferior myocardial infarction (IMI). METHODS: One hundred and fifty-eight consecutive patients with acute IMI treated with primary percutaneous coronary intervention, and 44 healthy subjects were included. RV myocardial involvement (RVMI) was defined as an elevation >1 mm in V1 or V4R and/or the presence of a culprit lesion at the proximal portion of the first RV marginal branch after reviewing coronary angiography. Patients were followed for 3 years to determine the cardiovascular mortality. RESULTS: Overall, 70 patients with IMI had RVMI. IMI patients had significantly higher RV peak systolic longitudinal strain dyssynchrony (PLSSD) index, lower peak longitudinal systolic strain (PLSS), longer time to PLSS, and time to PLSS differences compared to healthy controls while the patients with RVMI had significantly worse values compared to patients without RVMI and healthy controls. Twenty-seven patients (17.1%) died within 2 years. RVMI was more prevalent in mortality group, and they had significantly higher RV PSSD index, whereas they had lower RV free wall PLSS and longer time to PLSS differences. Receiver operating characteristics (ROC) analysis revealed that a RV PLSSD index > 65 ms predicted mortality with a sensitivity of 88.9% and specificity of 71.8% in IMI patients. CONCLUSIONS: Intra- and inter-ventricular dyssynhcrony may develop in patients with acute IMI, especially in those with RV involvement, which might have a negative effect on the prognosis of these patients.

The effect of cardiac rehabilitation on blood pressure, and on left atrial and ventricular functions in hypertensive patients.

PURPOSE: Hypertension is associated with left ventricular (LV) hypertrophy, impaired LV relaxation, and left atrial (LA) enlargement. Cardiac rehabilitation (CR) improves clinical outcomes in a broad spectrum of cardiac disease. The aim of our study was to determine the effect of CR on blood pressure (BP), and on LA and LV functions in hypertensive patients. METHODS: Thirty consecutive hypertensive patients who would undergo CR program, and 38 hypertensive patients who refused to undergo CR program were included. All patients underwent ambulatory BP monitoring and transthoracic echocardiography, which were repeated after completion of the CR program, or 12 weeks later in the control group. LA and LV functions were assessed by both speckle tracking and 3-dimensional echocardiography. N-terminal pro-brain natriuretic peptide (NT-proBNP) levels were assessed before and after CR. RESULTS: Although initial ambulatory BP values and NT-proBNP levels were similar between the groups, daily, day-time, and night-time BP and NT-proBNP were significantly lower in the CR group after rehabilitation. LA reservoir strain and LV global longitudinal strain of the CR group significantly increased after CR while no significant increase was observed in controls. CONCLUSION: CR improves LA and LV strain while lowering BP and should be encouraged in routine management of hypertensive patients.

SiRA: A Silicon Rhodamine-Binding Aptamer for Live-Cell Super-Resolution RNA Imaging.

Although genetically encoded light-up RNA aptamers have become promising tools for visualizing and tracking RNAs in living cells, aptamer/ligand pairs that emit in the far-red and near-infrared (NIR) regions are still rare. In this work, we developed a light-up RNA aptamer that binds silicon rhodamines (SiRs). SiRs are photostable, NIR-emitting fluorophores that change their open-closed equilibrium between the noncolored spirolactone and the fluorescent zwitterion in response to their environment. This property is responsible for their high cell permeability and fluorogenic behavior. Aptamers binding to SiR were in vitro selected from a combinatorial RNA library. Sequencing, bioinformatic analysis, truncation, and mutational studies revealed a 50-nucleotide minimal aptamer, SiRA, which binds with nanomolar affinity to the target SiR. In addition to silicon rhodamines, SiRA binds structurally related rhodamines and carborhodamines, making it a versatile tool spanning the far-red region of the spectrum. Photophysical characterization showed that SiRA is remarkably resistant to photobleaching and constitutes the brightest far-red light-up aptamer system known to date owing to its favorable features: a fluorescence quantum yield of 0.98 and an extinction coefficient of 86 000 M-1cm-1. Using the SiRA system, we visualized the expression of RNAs in bacteria in no-wash live-cell imaging experiments and also report stimulated emission depletion (STED) super-resolution microscopy images of aptamer-based, fluorescently labeled mRNA in live cells. This work represents, to our knowledge, the first application of the popular SiR dyes and of intramolecular spirocyclization as a means of background reduction in the field of aptamer-based RNA imaging. We anticipate a high potential for this novel RNA labeling tool to address biological questions.

Evaluation of right atrial volumes and functions by real-time three-dimensional echocardiography in patients after acute inferior myocardial infarction.

BACKGROUND: Right ventricle (RV) involvement causes acute systolic and diastolic functional alterations in the RV in patients after inferior myocardial infarction (IMI), which may result in an increase in left ventricle (LV) end-diastolic and right atrial (RA) pressure. In our study, we sought to evaluate RA volumes and mechanical functions using real-time three-dimensional echocardiography (RT3DE) in IMI patients with or without RV involvement. METHODS: Ninety-six consecutive patients with IMI (mean age: 59.7 ± 10.2 years, 60 female) were included. RV myocardial involvement (RVMI) was defined as the presence of a culprit lesion at the proximal portion of the first RV marginal branch in coronary angiography. The study population was divided into two groups: IMI (58.3%) and IMI + RVMI (41.7%). Patients were evaluated using conventional two-dimensional echocardiography (2DE) and RT3DE. RESULTS: In RT3DE measurements, IMI + RVMI patients had significantly higher RA phasic volumes and worse conduit mechanical function. A receiver operating characteristic (ROC) curve analysis revealed that an RT3DE RA maximum volume (Vmax) index > 27.9 mL/m2 was an independent predictor of RV involvement in patients after acute IMI, with a sensitivity of 80.0% and a specificity of 89.3%. CONCLUSIONS: Right ventricle involvement may cause an increase in RA phasic volumes and deterioration of conduit function in patients with acute IMI.

Dual-colour imaging of RNAs using quencher- and fluorophore-binding aptamers.

In order to gain deeper insight into the functions and dynamics of RNA in cells, the development of methods for imaging multiple RNAs simultaneously is of paramount importance. Here, we describe a modular approach to image RNA in living cells using an RNA aptamer that binds to dinitroaniline, an efficient general contact quencher. Dinitroaniline quenches the fluorescence of different fluorophores when directly conjugated to them via ethylene glycol linkers by forming a non-fluorescent intramolecular complex. Since the binding of the RNA aptamer to the quencher destroys the fluorophore-quencher complex, fluorescence increases dramatically upon binding. Using this principle, a series of fluorophores were turned into fluorescent turn-on probes by conjugating them to dinitroaniline. These probes ranged from fluorescein-dinitroaniline (green) to TexasRed-dinitroaniline (red) spanning across the visible spectrum. The dinitroaniline-binding aptamer (DNB) was generated by in vitro selection, and was found to bind all probes, leading to fluorescence increase in vitro and in living cells. When expressed in E. coli, the DNB aptamer could be labelled and visualized with different-coloured fluorophores and therefore it can be used as a genetically encoded tag to image target RNAs. Furthermore, combining contact-quenched fluorogenic probes with orthogonal DNB (the quencher-binding RNA aptamer) and SRB-2 aptamers (a fluorophore-binding RNA aptamer) allowed dual-colour imaging of two different fluorescence-enhancing RNA tags in living cells, opening new avenues for studying RNA co-localization and trafficking.

The 2013 ACC/AHA 10-year atherosclerotic cardiovascular disease risk index is better than SCORE and QRisk II in rheumatoid arthritis: is it enough?

OBJECTIVE: To determine the ability of the new American College of Cardiology and American Heart Association (ACC/AHA) 10-year atherosclerotic cardiovascular disease (ASCVD) risk algorithm in detecting high cardiovascular (CV) risk, RA patients identified by carotid ultrasonography (US) were compared with Systematic Coronary Risk Evaluation (SCORE) and QRisk II algorithms. METHODS: SCORE, QRisk II, 2013 ACC/AHA 10-year ASCVD risk and EULAR recommended modified versions were calculated in 216 RA patients. In sonographic evaluation, carotid intima-media thickness >0.90 mm and/or carotid plaques were used as the gold standard test for subclinical atherosclerosis and high CV risk (US+). RESULTS: Eleven (5.1%), 15 (6.9%) and 44 (20.4%) patients were defined as having high CV risk according to SCORE, QRisk II and ACC/AHA 10-year ASCVD risk, respectively. Fifty-two (24.1%) patients were US + and of those, 8 (15.4%), 7 (13.5%) and 23 (44.2%) patients were classified as high CV risk according to SCORE, QRisk II and ACC/AHA 10-year ASCVD risk, respectively. The ACC/AHA 10-year ASCVD risk index better identified US + patients than SCORE and QRisk II (P < 0.0001). With EULAR modification, reclassification from moderate to high risk occurred only in two, five and seven patients according to SCORE, QRisk II and ACC/AHA 10-year ASCVD risk, respectively. CONCLUSION: The 2013 ACC/AHA 10-year ASCVD risk estimator was better than the SCORE and QRisk II indices in RA, but still failed to identify 55% of high risk patients. Furthermore adjustment of threshold and EULAR modification did not work well.

Unusual Bleeding Due to Riociguat Use in a Patient With Chronic Thromboembolic Pulmonary Hypertension.

Riociguat is a new drug prescribed to patients with pulmonary hypertension that reduces the pressure in pulmonary artery by vasodilation. This drug like many other drugs has several side effects, some of which can be serious such as bleeding. Riociguat causes vaginal bleeding by increasing endometrial thickness and blood flow to the endometrium, therefore, should be used with care especially for patients who have history of dysfunctional uterine bleeding. In this case report, we present a 27-year-old female patient with chronic thromboembolic pulmonary hypertension and dysfunctional uterine bleeding presented with severe vaginal bleeding under riociguat treatment.

Is Dabigatran As Effective As Warfarin on Cardiac Thrombus in a Patient With Atrial Fibrillation? A Challenging Question.

Atrial fibrillation (AF) is an important risk factor for cardioembolic stroke. Warfarin is an effective treatment in reducing the risk of cardioembolic stroke in patients with AF. New anticoagulants have been widely using for stroke prophylaxis in patients with nonvalvular AF. Previous studies have suggested that thrombolytic therapy is effective treatment choice in patients with pulmonary embolisms. Warfarin therapy is also effective on prevention or treatment of cardiac thrombus in patients with AF. However, there are no evidence-based data on treatment of cardiac thrombus with new oral anticoagulants in patients with AF. In our case report, we reported an AF patient with cardiac thrombus and pulmonary embolism under dabigatran therapy.

Effect of acute sleep deprivation on left atrial mechanics assessed by three-dimensional echocardiography.

BACKGROUND: Although sleep deprivation (SD) affects cardiovascular system in many ways, physio-pathological changes in cardiac chamber volume and function have not been described well. The aim of the present study was to investigate the effect of SD on left atrial (LA) and ventricular function with three-dimensional (3D) echocardiography. METHODS: Thirty-two healthy individuals (12 females, mean age 33.25 ± 8.18) were evaluated. Echocardiographic examination was performed once after a night of regular sleep and a night of sleep debt. Beside conventional parameters, 3D phasic volumes and function were measured using a commercially available 3D echocardiography system and offline analysis software. RESULTS: Mean sleep duration of the study group was 8.15 ± 2.19 h in the day of regular sleep and 2.56 ± 2.25 h in the day of sleep deprivation. There was a significant prolongation in deceleration time (180.83 ± 15.34 vs. 166.44 ± 26.12; p = 0.044) and increase in E/e' (6.95 ± 1.26 vs. 6.38 ± 0.85; p = 0.005). Among 3D measurements, the difference in left ventricular ejection fraction (EF), LA EF, LA reservoir function and LA active EF were not significant. Mean LA passive EF of the individuals was significantly lower after night shift (24.10 ± 7.66 vs. 31.49 ± 7.75; p = 0.006). CONCLUSION: Acute SD is associated with a reduction in LA passive emptying function in healthy adults. 3D-derived indices were sufficient to show subclinical diastolic dysfunction according to impairment in passive phase of LA ejection. Prospective large-scale studies are needed to enlighten this issue.