Mitral isthmus ablation with and without temporary spot occlusion of the coronary sinus: a randomized clinical comparison of acute outcomes

To evaluate the safety and outcomes of mitral isthmus (MI) linear ablation with temporary spot occlusion of the coronary sinus (CS). Background: CS blood flow cools local tissue precluding transmurality and bidirectional block across MI lesion.

Disparate activation of the coronary sinus and inferior left atrium during atrial tachycardia after persistent atrial fibrillation ablation: prevalence, pitfalls, and impact on mapping

Persistent atrial fibrillation (AF) ablation may lead to partial disconnection of the coronary sinus (CS). As a result, disparate activation sequences of the local CS versus contiguous left atrium (LA) may be observed during atrial tachycardia (AT). We aimed to evaluate the prevalence of this phenomenon and its impact on activation mapping.

Cascading climate effects and related ecological consequences during past centuries

The interface between climate and ecosystem structure and function is incompletely understood, partly because few ecological records start before the recent warming phase. Here, we analyse an exceptional 100-yr long record of the great tit (Parus major) population in Switzerland in relation to climate and habitat phenology. Using structural equation analysis, we demonstrate an uninterrupted cascade of significant influences of the large-scale atmospheric circulation (North-Atlantic Oscillation, NAO, and North-sea – Caspian Pattern, NCP) on habitat and breeding phenology, and further on fitness-relevant life history traits within great tit populations. We then apply the relationships of this analysis to reconstruct the circulation-driven component of fluctuations in great tit breeding phenology and productivity on the basis of new seasonal NAO and NCP indices back to 1500 AD. According to the structural equation model, the multi-decadal oscillation of the atmospheric circulation likely led to substantial variation in habitat phenology, productivity and consequently, tit population fluctuations with minima during the "Maunder Minimum" (∼ 1650–1720) and the Little Ice Age Type Event I (1810–1850). The warming since 1975 was not only related with a quick shift towards earlier breeding, but also with the highest productivity since 1500, and thus, the impact of the NAO and NCP has contributed to an unprecedented increase of the population. A verification of the structural equation model against two independent data series (1970–2000 and 1750–1900) corroborates that the retrospective model reliably depicts the major long-term NAO/NCP impact on ecosystem parameters. The results suggest a complex cascade of climate effects beginning at a global scale and ending at the level of individual life histories. This sheds light on how large-scale climate conditions substantially affect major life history parameters within a population, and thus influence key ecosystem parameters at the scale of centuries.

Seasonal variations of ventricular arrhythmia clusters in defibrillator recipients

BACKGROUND: Clustering ventricular arrhythmias are the consequence of acute ventricular electrical instability and represent a challenge in the management of the growing number of patients with an implantable cardioverter-defibrillator (ICD). Triggering factors can rarely be identified. OBJECTIVES: Several studies have revealed seasonal variations in the frequency of cardiovascular events and life-threatening arrhythmias, and we sought to establish whether seasonal factors may exacerbate ventricular electrical instability leading to arrhythmia clusters and electrical storm. METHODS: Two hundred and fourteen consecutive defibrillator recipients were followed-up during 3.3 +/- 2.2 years. Arrhythmia cluster was defined as the occurrence of three or more arrhythmic events triggering appropriate defibrillator therapies within 2 weeks. Time intervals between two clusters were calculated for each month and each season, and were compared using Kruskal-Wallis test and Wilcoxon-Mann-Whitney test with Bonferroni adjustment. RESULTS: During a follow-up of 698 patient years, 98 arrhythmia clusters were observed in 51 patients; clustering ventricular arrhythmias were associated with temporal variables; they occurred more frequently in the winter and spring months than during the summer and fall. Accordingly, the time intervals between two clusters were significantly shorter during winter and spring (median and 95% CI): winter 16 (5-19), spring 11.5 (7-25), summer 34.5 (15-55), fall 50.5 (19-65), P = 0.0041. CONCLUSION: There are important seasonal variations in the incidence of arrhythmia clusters in ICD recipients. Whether these variations are related to environmental factors, change in physical activity, or psychological factors requires further study.

Femoroacetabular impingement: radiographic diagnosis--what the radiologist should know

OBJECTIVE: The purpose of this article is to show the important radiographic criteria that indicate the two types of femoroacetabular impingement: pincer and cam impingement. In addition, potential pitfalls in pelvic imaging concerning femoroacetabular impingement are shown. CONCLUSION: Femoroacetabular impingement is a major cause for early "primary" osteoarthritis of the hip. It can easily be recognized on conventional radiographs of the pelvis and the proximal femur.

All platelets are not equal: COAT platelets

Collagen- and thrombin-activated (COAT) platelets were first described in 2000 and have attracted considerable interest, changing the interpretation of the way in which platelets contribute to thrombin generation and how their procoagulant activity is organized. Platelets activated by two agonists coming from glycoprotein VI or Fc gamma-receptor IIA agonists on the one hand and thrombin on the other produce a population of approximately 50% highly procoagulant active platelets. This subgroup is formed by tissue transglutaminase and factor XIIIa linking of serotonin to the procoagulant proteins from granules or plasma, and these serotonylated proteins bind to fibrinogen or thrombospondin on the platelet surface. Serotonylation in the platelet cytoplasm has recently been shown to be an important regulating mechanism governing the activation of small GTPases and their function in granule release. Recent studies with Tph-/- mice in which the peripheral serotonin, including that in platelets, is very strongly reduced, have shown a prolonged bleeding time, suggesting it has an important hemostatic role in the release of platelet von Willebrand factor. More knowledge about how COAT platelets are formed will be important for a better understanding of the physiology and pathology of hemostasis.

Prediction of arrhythmic events after myocardial infarction based on signal-averaged electrocardiogram and ejection fraction

Trials on implantable cardioverter-defibrillators (ICD) for patients after acute myocardial infarction (AMI) have highlighted the need for risk assessment of arrhythmic events (AE). The aim of this study was to evaluate risk predictors based on a novel approach of interpreting signal-averaged electrocardiogram (SAECG) and ejection fraction (EF).

Fasting plasma glucose predicts survival and angiographic progression in high-risk postmenopausal women with coronary artery disease

BACKGROUND: We studied the association of baseline fasting plasma glucose (FPG) levels with survival and coronary artery disease (CAD) progression among postmenopausal women without unstable angina. METHODS: Women were recruited from seven centers in the Women's Angiographic Vitamin and Estrogen Trial (WAVE) (n = 423). Event follow-up was available for 400 women (65.1 +/- 8.5 years, 66% white, 92% hypertensive, 19% smokers, 67% hypercholesterolemic). Thirty-eight percent of the women had diabetes or FPG > 125 mg/dL, and 21% had a fasting glucose 100-125 mg/dL. Follow-up angiography was performed in 304 women. Cox regression was used to model survival from a composite outcome of death or myocardial infarction (D/MI, 26 events; median follow-up 2.4 years). Angiographic progression was analyzed quantitatively using linear regression accounting for baseline minimum lumen diameter (MLD), follow-up time, and intrasubject correlations using generalized estimating equations. Regression analyses were adjusted for follow-up time, baseline age, treatment assignment, and Framingham risk (excluding diabetes). RESULTS: Women with impaired fasting glucose/diabetes mellitus (IFG/DM) had a relative risk (RR) of D/MI of 4.2 ( p = 0.009). In all women, each 10 mg/dL increase in FPG was associated with an 11% increase ( p < 0.001) in the hazard of D/MI. Each 10 mg/dL increase in FPG was associated with a 6.8 mum decrease in MLD over the follow-up period ( p = 0.005). CONCLUSIONS: Higher FPG is associated with increased risk of D/MI and greater narrowing of the coronary lumen in women with CAD. Aggressive monitoring of glucose levels may be beneficial for secondary CAD prevention.

Diazepam versus fentanyl for premedication during percutaneous coronary intervention: results from the Myocardial Protection by Fentanyl during Coronary Intervention (PROFIT) Trial

BACKGROUND: Sedation is a cornerstone in the premedication for percutaneous coronary intervention (PCI). Benzodiazepines and opioids are frequently used. Previous results suggest that opioids mimic the adaptation to ischemia during repeated balloon inflations and may provide direct myocardial protection in addition to their sedative effect. However, no comparative data exist. METHODS: We conducted a prospective, randomized, controlled, single-blind trial comparing diazepam and fentanyl in 276 patients undergoing elective PCI. Patients were randomized to either diazepam 5 mg sublingually or fentanyl 0.05 mg or 0.1 mg intravenously at least 5 minutes prior to the first balloon inflation. The primary end-point was the postprocedural elevation of myocardial markers of necrosis defined as an elevation of cardiac troponin T > or = 0.01 ng/ml. RESULTS: The three groups had similar baseline clinical, angiographic, and procedural characteristics, with no significant differences in lesion morphology, procedural complexity, or adjunctive medical treatment. No significant variation in the hemodynamic response to the study drugs was observed in the three groups. The rate of postprocedural troponin T elevation was 28% in the diazepam group, 20% in the fentanyl 0.05 mg group, and 30% in the fentanyl 0.1 mg group (P = 0.26). Rates of postprocedural myocardial infarction were 3%, 2%, and 2%, respectively (P = 0.84), with one case of in-hospital death in the diazepam group and no urgent TVR in the whole study population. CONCLUSION: Although providing a well-tolerated alternative to diazepam for sedation during PCI, fentanyl did not provide additional cardioprotection assessed through the postinterventional elevation of cardiac troponin T during elective coronary intervention.

Elevated levels of placental growth factor represent an adaptive host response in sepsis

Recently, we demonstrated that circulating levels of vascular endothelial growth factor (VEGF) and placental growth factor (PlGF) are increased in sepsis (Yano, K., P.C. Liaw, J.M. Mullington, S.C. Shih, H. Okada, N. Bodyak, P.M. Kang, L. Toltl, B. Belikoff, J. Buras, et al. 2006. J. Exp. Med. 203:1447-1458). Moreover, enhanced VEGF/Flk-1 signaling was shown to contribute to sepsis morbidity and mortality. We tested the hypothesis that PlGF also contributes to sepsis outcome. In mouse models of endotoxemia and cecal ligation puncture, the genetic absence of PlGF or the systemic administration of neutralizing anti-PlGF antibodies resulted in higher mortality compared with wild-type or immunoglobulin G-injected controls, respectively. The increased mortality associated with genetic deficiency of PlGF was reversed by adenovirus (Ad)-mediated overexpression of PlGF. In the endotoxemia model, PlGF deficiency was associated with elevated circulating levels of VEGF, induction of VEGF expression in the liver, impaired cardiac function, and organ-specific accentuation of barrier dysfunction and inflammation. Mortality of endotoxemic PlGF-deficient mice was increased by Ad-mediated overexpression of VEGF and was blocked by expression of soluble Flt-1. Collectively, these data suggest that up-regulation of PlGF in sepsis is an adaptive host response that exerts its benefit, at least in part, by attenuating VEGF signaling.

Gender and the use of antiretroviral treatment in resource-constrained settings: findings from a multicenter collaboration

AIMS: To compare the gender distribution of HIV-infected adults receiving highly active antiretroviral treatment (HAART) in resource-constrained settings with estimates of the gender distribution of HIV infection; to describe the clinical characteristics of women and men receiving HAART. METHODS: The Antiretroviral Therapy in Lower-Income Countries, ART-LINC Collaboration is a network of clinics providing HAART in Africa, Latin America, and Asia. We compared UNAIDS data on the gender distribution of HIV infection with the proportions of women and men receiving HAART in the ART-LINC Collaboration. RESULTS: Twenty-nine centers in 13 countries participated. Among 33,164 individuals, 19,989 (60.3%) were women. Proportions of women receiving HAART in ART-LINC centers were similar to, or higher than, UNAIDS estimates of the proportions of HIV-infected women in all but two centers. There were fewer women receiving HAART than expected from UNAIDS data in one center in Uganda and one center in India. Taking into account heterogeneity across cohorts, women were younger than men, less likely to have advanced HIV infection, and more likely to be anemic at HAART initiation. CONCLUSIONS: Women in resource-constrained settings are not necessarily disadvantaged in their access to HAART. More attention needs to be paid to ensuring that HIV-infected men are seeking care and starting HAART.