Clinical practice. Newly diagnosed atrial fibrillation

Aggressive Rhythm Control Strategy in Atrial Fibrillation Patients Presenting at the Emergency Department: The HEROMEDICUS Study Design and Initial Results

Atrial fibrillation has progressively become a more common reason for emergency department visits, representing 0.5% of presenting reasons. Registry data have indicated that about 60% of atrial fibrillation patients who present to the emergency department are admitted, emphasizing the need for more efficient management of atrial fibrillation in the acute phase. Management of atrial fibrillation in the setting of the emergency department varies between countries and healthcare systems. The most plausible reason to justify a conservative rather than an aggressive strategy in the management of atrial fibrillation is the absence of specific guidelines from diverse societies. Several trials of atrial fibrillation treatment strategies, including cardioversion, have demonstrated that atrial fibrillation in the emergency department can be treated safely and effectively, avoiding admission. In the present study, we present the epidemiology and characteristics of atrial fibrillation patients presenting to the emergency department, as well as the impact of diverse management strategies on atrial-fibrillation-related hospital admissions. Lastly, the design and initial data of the HEROMEDICUS protocol will be presented, which constitutes an electrophysiology-based aggressive rhythm control strategy in patients with atrial fibrillation in the emergency department setting.

PPP1R12C Promotes Atrial Hypocontractility in Atrial Fibrillation

BACKGROUND

Atrial fibrillation (AF)-the most common sustained cardiac arrhythmia-increases thromboembolic stroke risk 5-fold. Although atrial hypocontractility contributes to stroke risk in AF, the molecular mechanisms reducing myofilament contractile function remain unknown. We tested the hypothesis that increased expression of PPP1R12C (protein phosphatase 1 regulatory subunit 12C)-the PP1 (protein phosphatase 1) regulatory subunit targeting MLC2a (atrial myosin light chain 2)-causes hypophosphorylation of MLC2a and results in atrial hypocontractility.

METHODS

Right atrial appendage tissues were isolated from human patients with AF versus sinus rhythm controls. Western blots, coimmunoprecipitation, and phosphorylation studies were performed to examine how the PP1c (PP1 catalytic subunit)-PPP1R12C interaction causes MLC2a dephosphorylation. In vitro studies of pharmacological MRCK (myotonic dystrophy kinase-related Cdc42-binding kinase) inhibitor (BDP5290) in atrial HL-1 cells were performed to evaluate PP1 holoenzyme activity on MLC2a. Cardiac-specific lentiviral PPP1R12C overexpression was performed in mice to evaluate atrial remodeling with atrial cell shortening assays, echocardiography, and AF inducibility with electrophysiology studies.

RESULTS

In human patients with AF, PPP1R12C expression was increased 2-fold versus sinus rhythm controls (P=2.0×10-2; n=12 and 12 in each group) with >40% reduction in MLC2a phosphorylation (P=1.4×10-6; n=12 and 12 in each group). PPP1R12C-PP1c binding and PPP1R12C-MLC2a binding were significantly increased in AF (P=2.9×10-2 and 6.7×10-3, respectively; n=8 and 8 in each group). In vitro studies utilizing drug BDP5290, which inhibits T560-PPP1R12C phosphorylation, demonstrated increased PPP1R12C binding with both PP1c and MLC2a and dephosphorylation of MLC2a. Mice treated with lentiviral PPP1R12C vector demonstrated a 150% increase in left atrial size versus controls (P=5.0×10-6; n=12, 8, and 12), with reduced atrial strain and atrial ejection fraction. Pacing-induced AF in mice treated with lentiviral PPP1R12C vector was significantly higher than in controls (P=1.8×10-2 and 4.1×10-2, respectively; n=6, 6, and 5).

CONCLUSIONS

Patients with AF exhibit increased levels of PPP1R12C protein compared with controls. PPP1R12C overexpression in mice increases PP1c targeting to MLC2a and causes MLC2a dephosphorylation, which reduces atrial contractility and increases AF inducibility. These findings suggest that PP1 regulation of sarcomere function at MLC2a is a key determinant of atrial contractility in AF.

Myosin Light Chain Dephosphorylation by PPP1R12C Promotes Atrial Hypocontractility in Atrial Fibrillation

Background

Atrial fibrillation (AF), the most common sustained cardiac arrhythmia, increases thromboembolic stroke risk five-fold. Although atrial hypocontractility contributes to stroke risk in AF, the molecular mechanisms reducing myofilament contractile function remain unknown. We tested the hypothesis that increased expression of PPP1R12C, the PP1 regulatory subunit targeting atrial myosin light chain 2 (MLC2a), causes hypophosphorylation of MLC2a and results in atrial hypocontractility.

Methods

Right atrial appendage tissues were isolated from human AF patients versus sinus rhythm (SR) controls. Western blots, co-immunoprecipitation, and phosphorylation studies were performed to examine how the PP1c-PPP1R12C interaction causes MLC2a de-phosphorylation. In vitro studies of pharmacologic MRCK inhibitor (BDP5290) in atrial HL-1 cells were performed to evaluate PP1 holoenzyme activity on MLC2a. Cardiac-specific lentiviral PPP1R12C overexpression was performed in mice to evaluate atrial remodeling with atrial cell shortening assays, echocardiography, and AF inducibility with EP studies.

Results

In human patients with AF, PPP1R12C expression was increased two-fold versus SR controls ( P =2.0×10 -2 , n=12,12 in each group) with > 40% reduction in MLC2a phosphorylation ( P =1.4×10 -6 , n=12,12 in each group). PPP1R12C-PP1c binding and PPP1R12C-MLC2a binding were significantly increased in AF ( P =2.9×10 -2 and 6.7×10 -3 respectively, n=8,8 in each group). In vitro studies utilizing drug BDP5290, which inhibits T560-PPP1R12C phosphorylation, demonstrated increased PPP1R12C binding with both PP1c and MLC2a, and dephosphorylation of MLC2a. Lenti-12C mice demonstrated a 150% increase in LA size versus controls ( P =5.0×10 -6 , n=12,8,12), with reduced atrial strain and atrial ejection fraction. Pacing-induced AF in Lenti-12C mice was significantly higher than controls ( P =1.8×10 -2 and 4.1×10 -2 respectively, n= 6,6,5).

Conclusions

AF patients exhibit increased levels of PPP1R12C protein compared to controls. PPP1R12C overexpression in mice increases PP1c targeting to MLC2a and causes MLC2a dephosphorylation, which reduces atrial contractility and increases AF inducibility. These findings suggest that PP1 regulation of sarcomere function at MLC2a is a key determinant of atrial contractility in AF.

Atopic dermatitis and risk of atrial fibrillation or flutter: A 35-year follow-up study

BACKGROUND

Atopic dermatitis is characterized by chronic inflammation, which is a risk factor for atrial fibrillation.

OBJECTIVE

To examine the association between hospital-diagnosed atopic dermatitis and atrial fibrillation.

METHODS

Using linked population-based Danish registries, we identified persons with an inpatient or outpatient hospital diagnosis of atopic dermatitis during 1977-2013 and a comparison cohort individually matched to the atopic dermatitis cohort. We followed cohorts until death, emigration, atrial fibrillation diagnosis, or end of study (January 1, 2013). We compared 35-year risk of atrial fibrillation and estimated hazard ratios with 95% confidence intervals using Cox regression, adjusting for birth year and sex. We validated 100 atopic dermatitis diagnoses from a dermatologic department through medical record review.

RESULTS

We included 13,126 persons with atopic dermatitis and 124,211 comparators and followed them for a median of 19.3 years. The 35-year risk of atrial fibrillation was 0.81% and 0.67%, respectively. The positive predictive value of atopic dermatitis diagnoses was 99%. The hazard ratio was 1.2 (95% confidence interval 1.0-1.6) and remained increased after adjusting for various atrial fibrillation risk factors.

LIMITATIONS

Analyses were limited to persons with moderate-to-severe atopic dermatitis, and we had no lifestyle data.

CONCLUSION

Patients with hospital-diagnosed atopic dermatitis have a 20% increased long-term risk of atrial fibrillation, but the absolute risk remains low.

Thyroid Nodules in Severely Obese Patients: Frequency and Risk of Malignancy on Ultrasonography

Background: We aimed to compare the thyroid ultrasonographic findings of severely obese versus nonobese individuals, and the frequency, characteristics, and risk of malignancy in detected nodules.Design: Case-control study including 67 adults with severe obesity (body mass index [BMI] ≥ 35 kg/m²) and 67 nonobese controls (BMI < 30 kg/m²). The participants underwent ultrasound evaluation of the thyroid and cervical subcutaneous tissue. The risk of malignancy in detected nodules was determined using the American Thyroid Association (ATA) 2015 and the Thyroid Imaging Reporting and Data System (TI-RADS) classifications. Fine-needle aspiration biopsy (FNAB) was performed in nodules for which the procedure was recommended according to the ATA-2015 or TI-RADS criteria, and the cytological evaluation followed the Bethesda classification.Results: The mean BMI values in the case and control groups were 47.0 ± 6.1 kg/m² and 22.8 ± 2.7 kg/m², respectively. There were no differences between groups regarding sex, age, total T3, and antiperoxidase (antiTPO) antibody positivity. When compared with controls, severely obese individuals showed a greater frequency of parenchymal hypoechogenicity (p = 0.042), cervical subcutaneous tissue thickness (p < 0.001), overall frequency of thyroid nodules (p = 0.038), and frequency of multiple nodules (p = 0.013). No significant differences were observed in terms of risk of nodular malignancy according to both the ATA-2015 and TI-RADS classifications in severely obese compared with nonobese individuals.Conclusions: Severely obese individuals (versus nonobese controls) presented increased parenchymal hypoechogenicity and frequency of thyroid nodules on ultrasonographic evaluation. However, no significant differences were observed in terms of risk of nodular malignancy between both groups according to the ATA-2015 and TI-RADS criteria. Thus, ultrasonographic thyroid screening of severely obese individuals is not justified.

Comparison of incidence of acute kidney injury, chronic kidney disease and end-stage renal disease between atrial fibrillation and atrial flutter: real-world evidences from a propensity score-matched national cohort analysis

We investigated the adverse renal outcomes in patients affected by either atrial fibrillation (Afib) or atrial flutter (AFL). Using the Taiwan National Health Insurance research database, both cohorts were 1:1 propensity score matched based on age, sex, index year, and comorbidity using logistic regression model. Hazard ratios (HRs) and corresponding 95% confidence intervals (CIs) of acute kidney injury (AKI), chronic kidney disease (CKD), and end-stage renal disease (ESRD) between the two cohorts were obtained using Cox proportional hazard regression models. Competing-risks regression models were applied to calculate the subhazard ratios (SHRs) and corresponding 95% CIs of the adverse renal outcomes. Afib patients were 1.15 and 1.33 times more likely to experience CKD and ESRD, respectively, than AFL patients (incidence rate per 10,000 person-years (IR): CKD, 10.8 vs 9.41; ESRD, 4.44 vs 3.34), with the adjusted HRs of 1.18 and 1.32 (CKD, 95% CI = 1.07-1.30; ESRD, 95% CI = 1.12-1.55). Afib patients were 1.08 times (95% CI = 1.01-1.16) more likely to have AKI than AFL patients after adjusting for confounding covariates. Competing risk analysis showed that Afib patients were 1.08 (95% CI = 1.01-1.15), 1.18 (95% CI = 1.07-1.30) and 1.32 (95% CI = 1.12-1.55) times more likely to experience AKI, CKD and ESRD than AFL subjects. This study showed that Afib conferred worse renal events of AKI, CKD and ESRD than AFL.

Low UBE4B expression increases sensitivity of chemoresistant neuroblastoma cells to EGFR and STAT5 inhibition

Neuroblastoma is the most common malignancy in infants. Overexpression of the epidermal growth factor receptor (EGFR) in neuroblastoma tumors underlies resistance to chemotherapeutics. UBE4B, an E3/E4 ubiquitin ligase involved in EGFR degradation, is located on chromosome 1p36, a region in which loss of heterozygosity is observed in approximately one-third of neuroblastoma tumors and is correlated with poor prognosis. In chemoresistant neuroblastoma cells, depletion of UBE4B yielded significantly reduced cell proliferation and migration, and enhanced apoptosis in response to EGFR inhibitor, Cetuximab. We have previously shown that UBE4B levels are inversely correlated with EGFR levels in neuroblastoma tumors. We searched for additional targets of UBE4B that mediate cellular alterations associated with tumorogenesis in chemoresistant neuroblastoma cells depleted of UBE4B using reverse phase protein arrays. The expression of STAT5a, an effector protein downstream of EGFR, doubled in the absence of UBE4B, and verified by quantitative immunoblotting. Chemoresistant neuroblastoma cells were treated with SH-4-54, a STAT5 inhibitor, and observed insignificant effects on cell proliferation, migration, and apoptosis. However, SH-4-54 significantly enhanced the anti-proliferative and anti-migratory effects of Cetuximab in naïve SK-N-AS neuroblastoma cells. Interestingly, in UBE4B depleted SK-N-AS cells, SH-4-54 significantly potentiated the effect of Cetuximab rendering cells increasingly sensitive an otherwise minimally effective Cetuximab concentration. Thus, neuroblastoma cells with low UBE4B levels were significantly more sensitive to combined EGFR and STAT5 inhibition than parental cells. These findings may have potential therapeutic implications for patients with 1p36 chromosome LOH and low tumor UBE4B expression.

Suicide attempt in patients with atrial fibrillation - A nationwide cohort study

BACKGROUND AND AIMS

We analyzed the incidence of suicide attempt in a Taiwanese population following admission to hospital between 2000 and 2010 for atrial fibrillation (AF).

METHODS

Using the National Health Insurance Research Database in Taiwan, the study cohort and the comparison cohort were 1-fold matched according to propensity score method. Cox proportion hazard regression models were used to examine the effect of AF on the risk of suicide attempt, and were shown as hazard ratios (HRs) and 95% confidence intervals (CIs). Mortality for patients who have made suicide attempts was subsequently compared between the AF and the non-AF cohorts.

RESULTS

The study included a cohort of 88,259 patients with AF and a non-AF cohort of 88,259 subjects. The overall incidence of suicide attempt for the AF and the non-AF cohorts were 5.75 and 3.97 per 10,000 person-years, respectively. AF patients were associated with an increased risk of suicide attempt compared with the non-AF controls [adjusted HR (aHR) = 1.47, 95% CI = 1.19-1.81] after controlling for the confounders. The incidence of mortality among patients who have made suicide attempts was not significantly higher in the AF cohort than in the non-AF cohort, with an adjusted HR of 1.11 (95% CI = 0.75-1.65).

CONCLUSIONS

We concluded that in this large database AF patients were related with higher incidence of suicide attempt.

Lifestyle of Patients with Atrial Fibrillation Following Self-Management Interventions: a Randomized Clinical Trial

Introduction: Cardiovascular diseases are the most common cause of death in most countries, such as Iran. Cardiac arrhythmias, including Atrial Fibrillation (AF) comprise an important category of these diseases. During recent years, AF has become a serious medical condition. This study aimed to investigate the effect of self-management interventions on the lifestyle of patients with AF. Methods: In this Randomized Clinical Trial study, 88 patients were selected and randomly assigned to intervention and control groups. The intervention group received self-management interventions, including education and telephone follow-ups. The data were collected using a demographic questionnaire and Walker's health-promoting lifestyle profile II, before the intervention and four and twelve weeks after the intervention. The significance level was considered to be 0.05. Results: The results showed a significant increase in the intervention group's lifestyle mean score, four and twelve weeks after the intervention as compared with control group However, this increase was not similar in all the lifestyle dimensions. Conclusion: In conclusion, implementation of self-management interventions could improve the lifestyle of the patients with Atrial Fibrillation. The results can help nurses to conduct self-management interventions into such patients' care plan and prevent many physical, psychological, and social problems that negatively affect patients and their lifestyle.

Risk of incident atrial fibrillation after a prior critical illness: A retrospective cohort study

OBJECTIVE

This investigation aimed at assessing the issue of incident atrial fibrillation (AF) associated with acute critical illness.

METHODS

The study came from Taiwan and used that nation's Longitudinal Health Insurance Database 2000. Using propensity score matching, multivariable adjustment and competing risk methods, the correlations between the new-onset AF and critical illness (septicemia/septic shock, acute myocardial infarction【AMI】, hemorrhagic stroke and ischemic stroke) were investigated.

RESULTS

This study consisted of 46470 patients in the critical illness cohort, 618998 persons in the general population cohort. Additionally, 37,060 critically ill patients were matched with 37060 control patients based on propensity score methods. Compared with general population cohort, patients with septicemia/septic shock were 3.12-fold more likely to develop AF (95% confidence interval 【CI】 = 2.88-3.39), followed by patients with ischemic stroke (adjusted hazard ratio【aHR】 = 1.96, 95% CI = 1.80-2.14), patients with AMI (aHR = 1.62, 95% CI = 1.32-2.00) and patients with hemorrhagic stroke (aHR = 1.46, 95% CI = 1.13-1.88). In addition, after controlling for the confounding factors and the competing risk of death, the critical illness cohort still exhibited a significantly higher risk of AF than the general population cohort (adjusted subhazard ratio [aSHR] = 2.66, 95% CI = 2.49-2.84).

CONCLUSIONS

Our study explored incident AF among patients with critical illness in their medical history. Patients with septicemia/septic shock were at the highest risk of developing new-onset AF among these critically ill patients.

Platelet reactivity in patients with chronic kidney disease undergoing percutaneous coronary intervention

This study aimed to evaluate the platelet reactivity in real-world patients with different chronic kidney disease (CKD) stages after percutaneous coronary intervention (PCI), and to examine whether high residual platelet reactivity (HRPR) is associated with higher incidence of adverse cardiovascular events in a 2-year follow up. A total of 10 724 consecutive patients receiving DAPT with aspirin and clopidogrel after PCI throughout 2013 were enrolled. We applied modified thromboelastography (mTEG) in 6745 patients. Kaplan-Meier analysis and Cox proportional regression analysis were applied to illustrate end points for patients. The prevalence of HRPR for adenosine diphosphate (ADP) was higher in patients with CKD3-5 than patients with CKD1-2 (47.0% vs. 37.3%, p = 0.002), but not for arachidonic acid (AA). No significant difference was observed for MACCE between patients with or without HRPR for ADP (HR 1.004, 95%CI: 0.864-1.167, p = 0.954). Patients with HRPR for ADP was associated with less bleeding events than patients without HRPR for ADP (HR 0.795, 95%CI: 0.643-0.982, p = 0.034). In this large cohort of real-world patients after PCI, the deterioration of renal function was linked to HRPR for ADP. HRPR was not associated with MACCE in patients with CKD in a 2-year follow up. Bleeding risks were significantly lower in PCI patients with versus without HRPR for ADP.

Use of CHA2DS2-VASc Score to Predict New-Onset Atrial Fibrillation in Chronic Obstructive Pulmonary Disease Patients - Large-Scale Longitudinal Study

BACKGROUND

The aim of this study was to assess the accuracy of CHA2DS2-VASc score in predicting new-onset atrial fibrillation (AF) in patients with chronic obstructive pulmonary disease (COPD).

METHODS AND RESULTS

A total of 50,430 COPD patients were enrolled in this study. The area under the receiver operating characteristic curve (AUC) and the Cox model c-statistic were used to assess the association between new-onset AF risk and CHA2DS2-VASc score in COPD patients. After adjustment for comorbidities other than the components of CHA2DS2-VASc score, risk of new-onset AF in COPD patients increased from 1.24 (95% confidence interval (CI): 1.01-1.52) for a score of 1, to 2.15 (95% CI: 1.62-2.86) for score ≥6 (trend test, P<0.001), compared with CHA2DS2-VASc score 0. The AUC for CHA2DS2-VASc score in predicting new-onset AF in COPD patients was 0.69 (95% CI: 0.68-0.70). The c-statistic of Cox model in predicting incident AF was 0.73.

CONCLUSIONS

Risk of new-onset AF in COPD patients increased with increasing CHA2DS2-VASc score. The predictive ability of the score was moderate. CHA2DS2-VASc score might be used as a screening tool for AF in COPD patients.

Guidelines on the management of atrial fibrillation in the emergency department: a critical appraisal

Several guidelines often exist on the same topic, sometimes offering divergent recommendations. For the clinician, it can be difficult to understand the reasons for this divergence and how to select the right recommendations. The aim of this study is to compare different guidelines on the management of atrial fibrillation (AF), and provide practical and affordable advice on its management in the acute setting. A PubMed search was performed in May 2014 to identify the three most recent and cited published guidelines on AF. During the 1-week school of the European School of Internal Medicine, the attending residents were divided in five working groups. The three selected guidelines were compared with five specific questions. The guidelines identified were: the European Society of Cardiology guidelines on AF, the Canadian guidelines on emergency department management of AF, and the American Heart Association guidelines on AF. Twenty-one relevant sub-questions were identified. For five of these, there was no agreement between guidelines; for three, there was partial agreement; for three data were not available (issue not covered by one of the guidelines), while for ten, there was complete agreement. Evidence on the management of AF in the acute setting is largely based on expert opinion rather than clinical trials. While there is broad agreement on the management of the haemodynamically unstable patient and the use of drugs for rate-control strategy, there is less agreement on drug therapy for rhythm control and no agreement on several other topics.

Cardiac Dysrhythmias during Donor Care

Organ procurement coordinators must treat various cardiac dysrhythmias (arrhythmias), including rhythm disturbances that may cause or follow a cardiac arrest, in about 15% to 50% of donors. Treatment decisions should be based on the particular dysrhythmia and its effect on donor blood pressure. Medications selected should be effective but short acting. In this article, data available in publications located through a PubMed search are reviewed and specific dysrhythmias that are likely to occur during donor care are described. Treatment recommendations are based on guidelines from the American Heart Association.

Protective effects of epigallocatechin-3 gallate on atrial electrical and structural remodeling in a rabbit rapid atrial pacing model

Epigallocatechin-3 gallate (EGCG) is the major catechin in green tea. The aim of this study is to investigate the effects of EGCG on atrial electrical and structural remodeling in a rabbit rapid atrial pacing (RAP) model. New Zealand white rabbits were subjected to RAP with or without EGCG treatment. The atrial electrophysiology was studied. ELISA, Western blots, and RT-PCR were performed to determine the level of the inflammation markers, oxidative stress, and fibrogenic agents. Atrial tissue was stained with Masson's trichrome stain for fibrosis detection. RAP rabbits showed a significantly shorter atrial effective refractory period than control rabbits. Higher AF inducibility and longer AF duration were seen in the RAP group. AERP of rabbits received high dose EGCG were prolonged compared to RAP rabbits, and AF inducibility and duration of rabbits received high dose EGCG were lower. RAP rabbits have higher inflammation markers, higher oxidative stress, and more significant fibrosis within atrium, while high dose intervention of EGCG can lower the inflammation, oxidative stress, and fibrosis induced by RAP. Results showed that EGCG have protective effects on atrial electrical and structural remodeling in a rabbit RAP model in terms of attenuating of inflammation and oxidative stress.

Different distribution of Helicobacter pylori EPIYA- cagA motifs and dupA genes in the upper gastrointestinal diseases and correlation with clinical outcomes in iranian patients

AIM

Our aim was to determine the EPIYA-cagA Phosphorylation sites and dupA gene in H. pylori isolates among patients with upper gastrointestinal diseases.

BACKGROUND

Pathogenicity of the cagA-positive Helicobacter pylori is associated with EPIYA motifs and higher number of EPIYA-C segments is a risk factor of gastric cancer, while duodenal ulcer-promoting gene (dupA) is determined as a protective factor against gastric cancer.

PATIENTS AND METHODS

A total of 280 non-repeated gastric biopsies obtained from patients undergoing endoscopy from January 2013 till July 2013. Samples were cultured on selective horse blood agar and incubated in microaerophilic atmosphere. The isolated organisms were identified as H. pylori by Gram staining and positive oxidase, catalase, and urease tests. Various motif types of cagA and the prevalence of dupA were determined by PCR method.

RESULTS

Out of 280 specimens, 128 (54.7%) isolated organisms were identified as H. pylori. Of 120 H. pylori isolates, 35.9% were dupA positive and 56.26% were cagA positive, while cagA with ABC and ABCC motifs were 55.5% and 44.5%, respectively. Fifty six percent of the isolates with the ABCC motif have had dupA genes. We also found a significant association between strains with genotypes of dupA-ABC and duodenal ulcer disease (p = 0.007).

CONCLUSION

The results of this study showed that the prevalence of cagA-positive H. pylori in Shiraz was as high as in western countries and higher numbers of EPIYA-C segments were seen in gastric cancer patients. We may also use dupA as a prognostic and pathogenic marker for duodenal ulcer disease and cagA with the segment C for gastric cancer and gastric ulcer disease in this region.

Atrial Fibrillation

Atrial fibrillation (AF) is a supraventricular tachyarrhythmia that results from the chaotic depolarization of atrial tissue. AF is the most common sustained cardiac dysrhythmia and the most common dysrhythmia diagnosed in US emergency departments. All patients with AF must have their cardioembolic risk assessed, even if sinus rhythm is restored. Novel oral anticoagulants may be considered instead of vitamin K antagonists for anticoagulation in patients with nonvalvular AF.

Association of the Ottawa Aggressive Protocol with rapid discharge of emergency department patients with recent-onset atrial fibrillation or flutter

Objective:

There is no consensus on the optimal management of recent-onset episodes of atrial fibrillation or flutter. The approach to these conditions is particularly relevant in the current era of emergency department (ED) overcrowding. We sought to examine the effectiveness and safety of the Ottawa Aggressive Protocol to perform rapid cardioversion and discharge patients with these arrhythmias.

Methods:

This cohort study enrolled consecutive patient visits to an adult university hospital ED for recent-onset atrial fibrillation or flutter managed with the Ottawa Aggressive Protocol. The protocol includes intravenous chemical cardioversion, electrical cardioversion if necessary and discharge home from the ED.

Results:

A total of 660 patient visits were included, 95.2% involving atrial fibrillation and 4.9% involving atrial flutter. The mean age of patients enrolled was 64.5 years. In total, 96.8% were discharged home and, of those, 93.3% were in sinus rhythm. All patients were initially administered intravenous procaïnamide, with a 58.3% conversion rate. A total of 243 patients underwent subsequent electrical cardioversion with a 91.7% success rate. Adverse events occurred in 7.6% of cases: hypotension 6.7%, bradycardia 0.3% and 7-day relapse 8.6%. There were no cases of torsades de pointes, stroke or death. The median lengths of stay in the ED were as follows: 4.9 hours overall, 3.9 hours for those undergoing conversion with procaïnamide and 6.5 hours for those requiring electrical conversion.

Conclusion:

This is the largest study to date to evaluate the Ottawa Aggressive Protocol, a unique approach to cardioversion for ED patients with recent-onset episodes of atrial fibrillation and flutter. Our data demonstrate that the Ottawa Aggressive Protocol is effective, safe and rapid, and has the potential to significantly reduce hospital admissions and expedite ED care.

Relationship between CHA2DS2-VASc score and atrial electromechanical function in patients with paroxysmal atrial fibrillation: A pilot study

BACKGROUND

CHA2DS2-VASc score is the most widely preferred method for prediction of stroke risk in patients with atrial fibrillation. We hypothesized that CHA2DS2-VASc score may represent atrial remodeling status, and therefore echocardiographic evaluation of left atrial electromechanical remodeling can be used to identify patients with high risk.

METHODS

A total of 65 patients who had documented diagnosis of paroxysmal atrial fibrillation (PAF) were divided into three risk groups according to the CHA2DS2-VASc score: patients with low risk (score=0, group 1), with moderate risk (score=1, group 2), and with high risk score (score ≥2, group 3). We compared groups according to atrial electromechanical intervals and left atrium mechanical functions.

RESULTS

Atrial electromechanical intervals including inter-atrial and intra-atrial electromechanical delay were not different between groups. However, parameters reflecting atrial mechanical functions including LA phasic volumes (Vmax, Vmin and Vp) were significantly higher in groups 2 and 3 compared with group 1. Likewise, LA passive emptying volume (LATEV) in the groups 2 and 3 was significantly higher than low-risk group (14.12±8.13ml/m(2), 22.36±8.78ml/m(2), 22.89±7.23ml/m(2), p: 0.031). Univariate analysis demonstrated that Vmax, Vmin and Vp were significantly correlated with CHA2DS2-VASc score (r=0.428, r=0.456, r=0.451 and p<0.001). Also, LATEV (r=0.397, p=0.016) and LA active emptying volume (LAAEV) (r=0.281, p=0.023) were positively correlated with CHA2DS2-VASc score. In the ROC analysis, Vmin≥11ml/m(2) has the highest predictive value for CHA2DS2-VASc score ≥2 (88% sensitivity and 89% specificity; ROC area 0.88, p<0.001, CI [0.76-0.99]).

CONCLUSION

Echocardiographic evaluation of left atrial electromechanical function might represent a useful method to identify patients with high risk.

Inflammatory bowel "Cardiac" disease: Point prevalence of atrial fibrillation in inflammatory bowel disease population

BACKGROUND/AIM

Proinflammatory markers such as interleukin (IL)-6 have been closely associated with atrial fibrillation (AF). These markers are characteristically elevated in chronic inflammatory bowel disease (IBD) and positively correlate with disease activity. Although IBD and AF have similar pathogenesis, there have been very limited studies looking at their association. The aim of this study is to determine the prevalence of AF in patients with IBD.

PATIENTS AND METHODS

Medical records of patients with biopsy proven IBD (n = 203, both in and outpatient) were retrospectively reviewed. One hundred and forty-one IBD patients with documentary evidence of electrocardiograms (ECG's) were included. The "Anticoagulation and Risk Factors in Atrial Fibrillation (ATRIA)" study, a large cross-sectional study (n = 1.89 million) done to evaluate the prevalence of AF among the US population, was our control population. All ECGs available till December 2010 for each IBD patient were reviewed carefully for evidence of AF. We studied the prevalence of AF among IBD population and compared it to that of control (ATRIA) population.

RESULTS

The prevalence of AF was significantly higher among IBD patients compared with the ATRIA study patients (11.3% vs 0.9%, P < 0.0001). Additionally, the IBD patient population were much younger compared with the controls (64.4 ± 10.7 vs 71.2 ± 12.2, P = 0.02).

CONCLUSION

AF has an overall higher prevalence across all age groups in IBD compared with the subjects of ATRIA study, which could be due to the chronic inflammatory state of IBD. Further studies are needed to study the association in detail.

Rac1-mediated effects of HMG-CoA reductase inhibitors (statins) in cardiovascular disease

SIGNIFICANCE

HMG-CoA reductase inhibitors (statins) lower serum cholesterol concentrations and are beneficial in the primary and secondary prevention of coronary heart disease. The positive clinical effects have only partially been reproduced with other lipid-lowering interventions suggesting potential statin effects in addition to cholesterol lowering. In experimental models, direct beneficial cardiovascular effects that are mediated by the inhibition of isoprenoids have been documented, which serve as lipid attachments for intracellular signaling molecules such as small Rho guanosine triphosphate-binding proteins, whose membrane localization and function are dependent on isoprenylation.

RECENT ADVANCES

Rac1 GTPase is an established master regulator of cell motility through the cortical actin reorganization and of reactive oxygen species generation through the regulation of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity.

CRITICAL ISSUES

Observations in cells, animals, and humans have implicated the activation of Rac1 GTPase as a key component of cardiovascular pathologies, including the endothelial dysfunction, cardiac hypertrophy and fibrosis, atrial fibrillation, stroke, hypertension, and chronic kidney disease. However, the underlying signal transduction remains incompletely understood.

FUTURE DIRECTIONS

Based on the recent advance made in Rac1 research in the cardiovascular system by using mouse models with transgenic overexpression of activated Rac1 or conditional knockout, as well as Rac1-specific small molecule inhibitor NSC 23766, the improved understanding of the Rac1-mediated effects statins may help to identify novel therapeutic targets and strategies.

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.

Atrial fibrillation-induced cardiac troponin I release

BACKGROUND

Cardiac troponin I (cTnI) is highly specific for myocardial damage and for the diagnosis of acute coronary syndrome. We investigated cTnI utility and predictive value in patients with atrial fibrillation (AF) in the acute setting.

METHOD

We studied 354 consecutive patients with the primary diagnosis of AF and clinical symptoms suggestive of myocardial ischemia presenting to our emergency department. cTnI was obtained on presentation. Patients with ST-segment elevation myocardial infarction were excluded. Coronary angiography was performed in 100 patients.

RESULTS

cTnI was elevated (>0.09 μg/L) in 51 of 354 (15%) patients. The mean cTnI in these patients was 0.37 μg/L (0.09-3.14). In 23 of 100 patients undergoing coronary angiography, cTnI was elevated. Only 6 of these 23 patients (26%) had significant stenosis. In 77 of 100 patients undergoing coronary angiography, cTnI was normal, revealing significant stenosis in 25 patients (33%). The positive predictive value of elevated cTnI for a coronary intervention was 26% and the negative predictive value was 68%. Using multivariate logistic regression, we found that heart rate on presentation, the presence of angina pectoris, left ventricular ejection fraction, serum creatinine, and hemoglobin independently predicted elevated cTnI level.

CONCLUSION

These data are the first to show that AF in the acute setting is frequently associated with cTnI elevations. AF patients with high heart rate and/or angina pectoris often show false elevated cTnI levels. These findings are relevant for clinicians evaluating patients with acute AF and myocardial ischemia symptoms. Appropriate clinical guidelines must be established that also consider AF-related elevations in cTnI.

Transitions of care in anticoagulation management for patients with atrial fibrillation

Thromboprophylaxis with oral anticoagulants (OACs) is an important but underused element of atrial fibrillation (AF) treatment. Reduction of stroke risk with anticoagulants comes at the price of increased bleeding risk. Patients with AF receiving anticoagulants require heightened attention with transition from one care setting to another. Patients presenting for emergency care of anticoagulant-related bleeding should be triaged for the severity and source of the bleeding using appropriate measures, such as discontinuing the OAC, administering vitamin K, when appropriate, to reverse warfarin-induced bleeding, or administering clotting factors for emergent bleeding. Reversal of OACs in patients admitted to the hospital for surgery can be managed similarly to patients with bleeding, depending on the urgency of the surgical procedure. Patients with AF who are admitted for conditions unrelated to AF should be assessed for adequacy of stroke risk prophylaxis and bleeding risk. Newly diagnosed AF should be treated in nearly all patients with either warfarin or a newer anticoagulant. Patient education is critically important with all anticoagulants. Close adherence to the prescribed regimen, regular international normalized ratio testing for warfarin, and understanding the stroke risk conferred by both AF and aging are goals for all patients receiving OACs. Detailed handoff from the hospitalist to the patient's primary care physician is required for good continuity of care. Monitoring by an anticoagulation clinic is the best arrangement for most patients. The elderly, or particularly frail or debilitated patients who are transferring to long-term care, need a detailed transfer of information between settings, education for the patient and family, and medication reconciliation. Communication and coordination of care among outpatient, emergency, inpatient, and long-term care settings are vital for patients with AF who are receiving anticoagulants to balance stroke prevention and bleeding risk.

Atrial fibrillation in the elderly -- not a benign condition

Atrial fibrillation (AF) is the most commonly seen arrhythmia and its prevalence increases with age. In the general population, rates of 1-2% are reported but in older patients, the rates increase to over 10% (in those aged 85years or older). Many older patients present to the emergency department (ED) with complaints that could be caused or associated with AF including valvular heart disease, hypertension, heart failure, an underlying infection (urinary or chest) and thyroid disorder. The most devastating complication of AF is stroke and early detection of AF and initiation of treatment (specifically the use of anti-coagulant medication) can significantly reduce the risk. AF is associated with high healthcare costs and has significant impacts on disability and quality of life especially if a stroke occurs. This review aims to describe the aetiology and treatment options for patients with newly diagnosed and previously diagnosed AF with an emphasis on how ED staff can manage older patients with AF and ensure optimal care is given. The treatment of AF has three main considerations (i) appropriateness for thromboembolic prophylaxis, (ii) rate control (including anti-arrhythmics, cardiac glycosides, B blockers and calcium channel blockers) and (iii) rhythm control with traditional cardioversion (either electrically or pharmacologically) or utilising interventional means to maintain sinus rhythm with cardiac surgery and more recently radio-frequency ablation. As anti-coagulation is widely implemented, the risks and benefits associated with warfarin and the newer agents will be described. Given that more than half of those with AF are over 75years and 30% of AF is diagnosed incidentally, there is an imperative for prompt diagnosis to reduce the risk of debilitating complications especially stroke. AF should not be viewed as yet another concomitant "benign" condition. Emergency staff are well placed to detect AF and ensure appropriate treatment is commenced to reduce the adverse events associated with it.

Atrial Fibrillation at an Internal Medicine Ward: Clinical and Prognostic Implications

Background: Little is known about atrial fibrillation (AF) appearing during hospitalization in an Internal Medicine ward. Purpose: We aimed to investigate characteristics and prognostic significance of in-hospital onset AF. Methods: We studied 249 consecutive unselected patients admitted to this medical department with paroxysmal or persistent AF (out-of-hospital group) or AF developed during hospitalization (in-hospital group). Demographic, clinical, laboratory, electrocardiographic and echocardiographic data and all-cause mortality following discharge were recorded and compared between the groups Results: Diabetes mellitus (p=0.05), renal dysfunction (p<0.001), chronic lung disease (p=0.03) and history of stroke (p=0.01) were found more common in the in-hospital group (56 patients), compared to the out-of-hospital group (193 patients). Patients from the in-hospital group were more likely to have recurrent episodes of AF during hospitalization (p=0.002), were more frequently treated with amiodarone (p<0.001), discharged in sinus rhythm (p=0.04) and with medications for rhythm control (p=0.04). Time from onset to termination of AF (p<0.001) and hospital stay (p<0.001) were longer in the in-hospital group. On a median of 39-months follow-up, survival rate was lower in the in-hospital vs. out-of-hospital group (69.6% vs. 81.3%, p=0.025). Older age was significantly associated with shorter survival in the in-hospital group [odds ratio (OR)=1.87, 95% confidence interval (CI) 1.15-3.03, p=0.009]. In the out-of-hospital group, advanced age (OR=2.17, 95%CI 1.51-3.10, p<0.001), no prior AF episode (OR=3.41, 95%CI 1.56-7.46, p=0.002), diabetes mellitus (OR=2.22, 95%CI 1.12-4.39, p=0.006) and renal dysfunction (OR=2.44, 95%CI 1.10-5.38, p=0.049) were significantly associated with shorter survival. Conclusion: Patients developing in-hospital AF differed from subjects hospitalized for AF with respect to the severity of the clinical profile and prognosis.

"Wait and see" approach to the emergency department cardioversion of acute atrial fibrillation

Objective. Acute atrial fibrillation often spontaneously resolves. This study aimed to investigate the outcomes and satisfaction of an evidence-based ED protocol employing a "wait and see" approach. Methods. A prospective observational cohort study of adult patients presenting to the Emergency Department with stable acute atrial fibrillation was performed. Patients were excluded if they were considered to be unstable, need hospitalization, or poor candidates for ED procedural sedation. Routine care was provided on the index visit, and suitable candidates were discharged and asked to return to the ED the following day for possible electrical cardioversion. Outcome measures included spontaneous reversion to sinus rhythm, success of cardioversion, length of stay, adverse event and return visits for AF within 30 days, and patient satisfaction. Results. Thirty five patient encounters were analysed over a 21-month period. Twenty two of the 35 patients (63%) had spontaneous resolution of atrial fibrillation upon presentation for potential cardioversion. All of the remaining patients underwent successful cardioversion to normal sinus rhythm without significant adverse events recorded. No patients required hospitalization. Three patients (9%) returned to the ED within 30 days for recurrence of atrial fibrillation. All patients were reported to be "very satisfied" with this approach. Conclusion. A "wait and see" approach to the ED electrical cardioversion of atrial fibrillation showed that almost two-thirds of patients had spontaneous resolution without requiring cardioversion or observation in the ED or hospital. All patients were successfully reverted to normal sinus rhythm and had a high degree of satisfaction.

Atrial fibrillation and heart failure parallels: lessons for atrial fibrillation prevention

Heart failure (HF) and atrial fibrillation (AF) are 2 of the most common cardiovascular diseases encountered in clinical practice, and the prevalence of these diseases continues to grow worldwide with the aging of the global population. While recognizing that AF is a heterogeneous disorder, we submit that the parallels between AF and HF may arise because many cases of AF and HF result from the cumulative exposure of the atria and ventricles to a common set of systemic cardiovascular risk factors. Over time, exposure to risk factors promotes development of atrial and ventricular structural and functional abnormalities through activation of several biologic pathways in concert: upregulation of neurohormonal signaling cascades, release of inflammatory mediators, programmed cell death, and fibrosis. Cardiac structural remodeling occurs in concert with electrophysiologic remodeling, both of which contribute to atrial and ventricular rhythm disturbances, including AF. AF and HF, instead of representing distinct disease processes, often represent different endpoints along a disease continuum. By reviewing some of the mechanistic parallels between AF and HF, we hope to emphasize the connection between established cardiovascular risk factors, cardiac remodeling and AF, with a view to promote strategies for AF prevention.

Diagnosis and treatment of atrial fibrillation in the acute care setting

PURPOSE

To discuss the causes of atrial fibrillation (AF), risk factors, and pathophysiology, and review current treatment guidelines for AF in the inpatient setting.

DATA SOURCES

Peer-reviewed medical and nursing journals, American College of Cardiology (ACC), American Heart Association (AHA), and European Society of Cardiology (ESC) practice guidelines.

CONCLUSIONS

There are many predisposing factors to AF and a variety of treatment modalities. Nurse practitioners (NPs) should acquaint themselves with the pathophysiology and evidence-based treatments in order to provide individually based care to patients.

IMPLICATIONS FOR PRACTICE

Pharmacological management is often warranted in patients with AF. NPs must be aware of updated clinical evidence in order to properly treat patients to provide symptomatic relief and improve quality of life.

Isolated proximal leg paresis due to a small cortical infarction

We describe two patients with small cortical infarcts, who presented with isolated proximal weakness in one of their legs. These lesions were located in the contralateral precentral gyrus, more medial than the precentral knob, but more lateral than the topmost part of the motor cortex. These clinical findings are consistent with the physiological findings of Penfield and Boldrey, and those of recent activation studies by functional MRI. It is clinically important to pay close attention to the contralateral top of the motor cortex when examining pure motor monoparesis of a proximal part of a lower extremity.