Dobutamine stress echocardiography in a patient with Wolff-Parkinson-White syndrome

We describe the case of a patient with ventricular pre-excitation who underwent dobutamine stress echocardiography to evaluate atypical chest pain. The patient safely underwent the procedure with interesting electrocardiographic findings during pharmacological stress. The risks of dobutamine stress testing, along with possible explanations of this observed event, are discussed. In conclusion, the safety of dobutamine stress testing in patients with ventricular pre-excitation has not been established; further prospective studies are needed to decide whether dobutamine stress testing is safe in certain subsets of this population. (Cardiol J 2011; 18, 4: 437–440

Outcome of all-comers with STEMI based on the grade of ischemia in the presenting ECG

Background: Grade 3 ischemia (G3I) in the 12 lead electrocardiogram (ECG) predicts poor outcome in patients with ST-elevation myocardial infarction (STEMI). The outcome of G3I in "real-life" patient cohorts is unclear. Methods: The aim of the study was to establish the prognostic significance of grade 2 ischemia (G2I), G3I and the STEMI patients excluded from ischemia grading (No grade of ischemia, NG) in a real-life patient population. We assessed in-hospital, 30-day and 1-year mortality as well as other endpoints. Results: The NG patients had more comorbidities and longer treatment delays than the two other groups. Shortterm and 1-year mortality were highest in patients with NG and lowest in patients with G2I. Maximum troponin level was highest in G3I, followed by NG and G2I. In logistic regression multivariable analysis, NG was independently associated with 1-year mortality. Conclusions: NG predicted poor outcome in STEMI patients. G2I predicted relatively favorable outcome. (C) 2018 Elsevier Inc. All rights reserved.Peer reviewe

Thrombolysis is an effective and safe therapy in stuck bileaflet mitral valves in the absence of high-risk thrombi

AbstractOBJECTIVESWe sought to evaluate the effectiveness and safety of thrombolytic therapy in stuck mitral bileaflet heart valves in the absence of high-risk thrombi.BACKGROUNDCurrent recommendations for the thrombolytic treatment of stuck prosthetic mitral valves are partially based on older valve models and inclusion of patients in whom high-risk thrombi were either ignored or not sought for. The feasibility and safety of thrombolysis in bileaflet models may be affected by the predilection of thrombi to catch the leaflet hinge.METHODSWe studied 12 consecutive patients (men/women = 5/7, age 58.8 ± 14.9 years) who experienced one or more episodes of stuck bileaflet mitral valve over a 33-month period and received thrombolytic therapy with streptokinase, urokinase or tissue-type plasminogen activator. Transesophageal echocardiography was performed in all patients. Patients with mobile or large (>5 mm) thrombi were excluded. Functional class at initial episode was I–II in 4 patients (33.3%) and III–IV in 8 patients (66.6%).RESULTSPatients receiving thrombolytic therapy achieved an overall 83.3% freedom from a repeat operation or major complications (95% confidence interval 51.6–97.9%). Minor bleeding occurred in three patients (25%) and allergic reaction in one (8.3%). Transient vague neurologic complaints, without subjective findings, occurred in four patients (33.3%). Three patients had one or more relapses within 5.2 ± 3.1 months from the previous episode, and readministration of thrombolytics was successful.CONCLUSIONSIn clinically stable patients with stuck bileaflet mitral valves and no high-risk thrombi, thrombolysis is highly successful and safe, both in the primary episode and in recurrence. The best thrombolytic regimen is yet to be established

Circulating miRNA Expression Profiling and Target Prediction in Patients Receiving Dexmedetomidine

Background/Aims: Circulating miRNAs could serve as biomarkers for diagnosis or prognosis of heart diseases and cerebrovascular diseases. Dexmedetomidine has protective effects in various organs. The effects of dexmedetomidine on circulating miRNAs remain unknown. Here, we investigated differentially expressed miRNA and to predict the target genes of the miRNA in patients receiving dexmedetomidine. Methods: The expression levels of circulating miRNAs of 3 patients were determined through high through-put miRNA sequencing technology. Target genes of the identified differentially expressed miRNAs were predicted using TargetScan 7.1 and miRDB v.5. Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) were used to conduct functional annotation and pathway enrichment analysis of target genes respectively. Results: Twelve differentially expressed miRNAs were identified. Five miRNAs were upregulated (hsa-miR-4508, hsa-miR-novel-chr8_87373, hsa-miR-30a-3p, hsa-miR-novel-chr16_26099, hsa-miR-4306) and seven miRNAs (hsa-miR-744-5p, hsa-miR-320a, hsa-miR-novel-chr9_90035, hsa-miR-101-3p, hsa-miR-150-5p, hsa-miR-342-3p, and hsa-miR-140-3p) were downregulated after administration of dexmedetomidine in the subjects. The target genes and pathways related to the differentially expressed miRNAs were predicted and analyzed. Conclusion: The differentially expressed miRNAs may be involved in the mechanisms of action of dexmedetomidine. Specific miRNAs, such as hsa-miR-101-3p, hsa-miR-150-5p and hsa-miR-140-3p, are new potential targets for further functional studies of dexmedetomidine

Разработка и исследование автономной системы управления солнечной батареи

В данной работе выполнен анализ динамических характеристик системы ориентации солнечной батареи, осуществляющей слежение за перемещением солнца с использованием MatLab-моделирования. Отслеживание таких объектов возможно при условии знания его координат. Одним из требований, предъявляемых к следящему электроприводу, являются требования минимума статической и динамической ошибок позиционирования устройства. При эксплуатации систем слежения в удаленных местах так же появляется требование по сокращению потребления электроэнергии самой системы. Для снижения электропотребления необходимо уменьшать колебания антенны в режиме слежения.In this work, an analysis is made of the dynamic characteristics of a solar battery orientation system that monitors the movement of the sun using MatLab modeling. Tracking of such objects is possible under condition of knowledge of its coordinates. One of the requirements for a servomotor drive is the requirements of a minimum of static and dynamic device positioning errors. When operating tracking systems in remote locations, there is also a requirement to reduce the electricity consumption of the system itself. To reduce power consumption, it is necessary to reduce antenna oscillations in tracking mode

Circulating blood cells and extracellular vesicles in acute cardioprotection

During an ST-elevation myocardial infarction (STEMI), the myocardium undergoes a prolonged period of ischaemia. Reperfusion therapy is essential to minimize cardiac injury but can paradoxically cause further damage. Experimental procedures to limit ischaemia and reperfusion (IR) injury have tended to focus on the cardiomyocytes since they are crucial for cardiac function. However, there is increasing evidence that non-cardiomyocyte resident cells in the heart (as discussed in a separate review in this Spotlight series) as well as circulating cells and factors play important roles in this pathology. For example, erythrocytes, in addition to their main oxygen-ferrying role, can protect the heart from IR injury via the export of nitric oxide bioactivity. Platelets are well-known to be involved in haemostasis and thrombosis, but beyond these roles, they secrete numerous factors including sphingosine-1 phosphate (S1P), platelet activating factor (PAF) and cytokines that can all strongly influence the development of IR injury. This is particularly relevant given that most STEMI patients receive at least one type of platelet inhibitor. Moreover, there are large numbers of circulating vesicles in the blood, including microvesicles and exosomes, which can exert both beneficial and detrimental effects on IR injury. Some of these effects are mediated by the transfer of miRNA to the heart. Synthetic miRNA molecules may offer an alternative approach to limiting the response to IR injury. We discuss these and other circulating factors, focussing on potential therapeutic targets relevant to IR injury. Given the prevalence of co-morbidities such as diabetes in the target patient population, their influence will also be discussed. This article is part of a Cardiovascular Research Spotlight Issue entitled 'Cardioprotection Beyond the Cardiomyocyte', and emerged as part of the discussions of the European Union (EU)-CARDIOPROTECTION Cooperation in Science and Technology (COST) Action, CA16225