68 research outputs found

    Dietary supplements containing prohibited substances: A review (Part 2)

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    The role of prohormones, ‘classic’ and ‘designer’ steroids, clenbuterol, peptide hormones and newer molecules causing concern in dietary supplements is discussed. Apart from their potential adverse effects on athletes’ health, their non-achievement of increased strength and muscle size, trace quantities present in contaminated dietary supplements can lead to failed doping tests. The methodologies used for the identification and determination of prohibited substances in very low concentrations, mainly liquid chromatography and mass spectrometry, are also addressed. Of concern is the anticipation that the number of dietary supplements containing (not yet) prohibited designer steroids and other performance-enhancing newer chemical entities will increase. Athletes, coaches and sports doctors should therefore be provided with information regarding dietary supplements and be advised to minimise risks for non-intentional ingestion of forbidden substances by using safe products listed on databases, such as those obtainable in The Netherlands and Germany.

    Dietary supplements containing prohibited substances: A review (Part 1)

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    Dietary supplements and chemical agents have been used for a number of decades among athletes striving to achieve increased strength and performance. This has led to a huge, growing market for the food supplement industry. The latter’s products are classified as ‘foods’ rather than drugs and are therefore free of the stringent requirements for registration of pharmaceuticals, i.e. no safety and efficacy data are required prior to registration. During the past decade, some dietary supplements have been shown to contain pharmaceutically active components not adequately identified on their package labels. These pharmaceuticals may have unintentionally entered the product or may have been intentionally added. Although the concentrations of these substances may be low and devoid of health or performance-enhancing effects, they may lead to positive doping tests. In Part 1 of this two-part review, a selection of the World Anti-Doping Agency-prohibited illegal stimulants, i.e. ephedrine, pseudoephedrine, sibutramine and methylhexaneamine, are discussed. Certain food supplement labels do mention the presence of natural sources of illegal stimulants, e.g. Ephedra sinica (ephedrine), but do not refer to the chemical entities of ephedrine and its analogues as such. The pharmacological adverse effects of stimulants, in particular those on the cardiovascular system, are briefly reviewed. Suggestions for avoiding these pitfalls are made.

    Focus on Diagnosis and Prognosis to Guide Timing of Intervention in Valvular Heart Disease

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    Purpose of Review The present article reviews the role of multimodality imaging to improve risk stratification and timing of intervention in patients with valvular heart disease (VHD), and summarizes the latest developments in transcatheter valve interventions.Recent Findings Growing evidence suggests that intervention at an earlier stage may improve outcomes of patients with significant VHD. Multimodality imaging, including strain imaging and tissue characterization with cardiac magnetic resonance imaging, has the ability to identify early markers of myocardial damage and can help to optimize the timing of intervention. Transcatheter interventions play an increasing role in the treatment of patients who remain at high surgical risk or present at a late stage of their disease.Summary Multimodality imaging identifies markers of cardiac damage at an early stage in the development of VHD. Together with technological innovations in the field of percutaneous valvular devices, these developments have the potential to improve current management and outcomes of patients with significant VHD.</p

    Effect of Bi-Atrial Size and Function in Patients With Paroxysmal or Permanent Atrial Fibrillation

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    Atrial fibrillation (AF) remains the most common arrhythmia in clinical practice. The choice between a rate-control and rhythm-control strategy depends on various factors, including the anatomical and functional substrate. This study investigates the anatomical and functional characteristics of both atria in patients with AF and explores the potential therapeutic implications. From an ongoing registry of patients with paroxysmal or permanent AF, those who underwent cardiac computed tomography (CCT) were included. Left atrial (LA) and right atrial (RA) sizes were measured on CCT, whereas bi-atrial function was quantified with speckle tracking strain echocardiography. The mean LA volume index was 41.6 ± 5.6 ml/m2, and the mean RA volume index was 71.0 ± 21.6 ml/m2. Mean LA reservoir strain was 24.3 ± 15.1%, compared with the mean RA reservoir strain of 21.6 ± 13.2%. Patients with smaller LA volumes had higher LA reservoir strain values than those with larger LA volumes (24.6% [interquartile range (IQR) 15.8 to 35.8] vs 16.5% [IQR 11.2 to 25.0], p 2 vs 36.9 [IQR 30.1 to 47.1] ml/m2, p = 0.025) compared with paroxysmal AF. Patients with permanent AF had more impaired LA reservoir strain (15.5% [IQR 11.6 to 22.7] vs 26.9% [IQR 17.4 to 35.6], p <0.001) compared with paroxysmal AF. Similar trends were observed in the RA. In conclusion, atrial substrate characterization by CCT and speckle tracking strain echocardiography may have therapeutic implications, especially for choosing between a rate-control and rhythm-control strategy

    Introduction to hemodynamic forces by echocardiography

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    Hemodynamic force (HDF) analysis represents a novel approach to quantify intraventricular pressure gradients, responsible for blood flow. A new mathematical model allows the derivation of HDF parameters from routine transthoracic echocardiography, making this tool more accessible for clinical use. HDF analysis is considered the fluid dynamics correlate of deformation imaging and may be even more sensitive to detect mechanical abnormalities. This has the potential to add incremental clinical value, allowing earlier detection of pathology or immediate evaluation of response to treatment. In this article, the theoretical background and physiological patterns of HDF in the left ventricle are provided. In pathological situations, the HDF pattern might alter, which is illustrated with a case of ST segment elevation myocardial infarction and non-ischemic cardiomyopathy with typical left bundle branch block

    Tricuspid regurgitation after cardiac resynchronization therapy: evolution and prognostic significance

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    Aims Tricuspid regurgitation (TR) is common in patients with heart failure (HF) and is associated with worse outcome. This study investigated the effect of cardiac resynchronization therapy (CRT) on TR severity and long-term outcome. Methods and results Tricuspid regurgitation severity was assessed at baseline and 6 months after CRT implantation, using a multiparametric approach. Patients were divided into four groups: (i) no or mild TR without progression; (ii) no or mild TR with progression to significant (moderate-severe) TR; (iii) significant TR with improvement to no or mild TR; and (iv) significant TR without improvement. The primary endpoint was all-cause mortality. A total of 852 patients (mean age 65 +/- 11 years, 77% male) were included. At baseline, 184 (22%) patients had significant TR, with 75 (41%) showing significant improvement at 6-month follow-up. After a median follow-up of 92 (50-137) months, 494 (58%) patients died. Patients with significant TR showing improvement at follow-up had better outcomes than those showing no improvement (P = 0.016). On multivariable analysis, no or mild TR progressing to significant TR [hazard ratio (HR) 1.745; 95% confidence interval (CI): 1.287-2.366; P < 0.001] and significant TR without improvement (HR 1.572; 95% CI: 1.198-2.063; P = 0.001) were independently associated with all-cause mortality, whereas significant TR with improvement at follow-up was not (HR: 1.153; 95% CI: 0.814-1.633; P = 0.424). Conclusion Improvement of significant TR after CRT is observed in a substantial proportion of patients, highlighting the potential benefit of CRT for patients with HF having significant TR. Significant TR at 6 months after CRT is independently associated with increased long-term mortality

    Myocardial Work, an Echocardiographic Measure of Post Myocardial Infarct Scar on Contrast-Enhanced Cardiac Magnetic Resonance

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    This study investigates the relation of non-invasive myocardial work and myocardial viability following ST-segment elevation myocardial infarction (STEMI) assessed on late gadolinium contrast enhanced cardiac magnetic resonance (LGE CMR) and characterizes the remote zone using non-invasive myocardial work parameters. STEMI patients who underwent primary percutaneous coronary intervention (PCI) were included. Several non-invasive myocardial work parameters were derived from speckle tracking strain echocardiography and sphygmomanometric blood pressure, e.g.: myocardial work index (MWI), constructive work (CW), wasted work (WW) and myocardial work efficiency (MWE). LGE was quantified to determine infarct transmurality and scar burden. The core zone was defined as the segment with the largest extent of transmural LGE and the remote zone as the diametrically opposed segment without LGE. A total of 53 patients (89% male, mean age 58 ± 9 years) and 689 segments were analyzed. The mean scar burden was 14 ± 7% of the total LV mass, and 76 segments (11%) demonstrated transmural hyperenhancement, 280 (41%) non-transmural hyperenhancement and 333 (48%) no LGE. An inverse relation was observed between segmental MWI, CW and MWE and infarct transmurality (p < 0.05). MWI, CW and MWE were significantly lower in the core zone compared to the remote zone (p<0.05). In conclusion, non-invasive myocardial work parameters may serve as potential markers of segmental myocardial viability in post-STEMI patients who underwent primary PCI. Non-invasive myocardial work can also be utilized to characterize the remote zone, which is an emerging prognostic marker as well as a therapeutic target

    Left Atrial Reservoir Function and Outcomes in Secondary Mitral Regurgitation

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    BackgroundLeft atrial (LA) size is a marker of disease severity and is related to worse outcomes in secondary mitral regurgitation (MR). The prognostic value of LA function assessed by LA reservoir strain (LARS), however, remains unknown. The aim of this study was to investigate the prognostic implications of LARS in patients with significant secondary MR.MethodsLARS was evaluated using speckle-tracking echocardiography in patients with more than mild (grade ≥ 2) secondary MR. The population was divided into two groups according to the median LARS value (9.8%). The primary end point was all-cause mortality.ResultsA total of 666 patients (mean age, 66 ± 11 years; 68% men) were included. On multivariable analysis, more severe MR was independently associated with more impaired LARS (LARS P = .001). During a median follow-up period of 5 years (interquartile range, 2-10), 383 patients (58%) died. Patients with LARS P P ConclusionsLARS is independently associated with all-cause mortality in patients with significant secondary MR and has incremental prognostic value over LA volume and left ventricular global longitudinal strain. LARS may improve risk stratification of patients with secondary MR.</p
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