| 1. |
- Teixeira, C A, et al.
(författare)
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EPILAB: A software package for studies on the prediction of epileptic seizures
- 2011
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Ingår i: Journal of Neuroscience Methods. - : Elsevier. - 0165-0270 .- 1872-678X. ; 200:2, s. 257-271
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Tidskriftsartikel (refereegranskat)abstract
- A Matlab (R)-based software package, EPILAB, was developed for supporting researchers in performing studies on the prediction of epileptic seizures. It provides an intuitive and convenient graphical user interface. Fundamental concepts that are crucial for epileptic seizure prediction studies were implemented. This includes, for example, the development and statistical validation of prediction methodologies in long-term continuous recordings. less thanbrgreater than less thanbrgreater thanSeizure prediction is usually based on electroencephalography (EEG) and electrocardiography (ECG) signals. EPILAB is able to process both EEG and ECG data stored in different formats. More than 35 time and frequency domain measures (features) can be extracted based on univariate and multivariate data analysis. These features can be post-processed and used for prediction purposes. The predictions may be conducted based on optimized thresholds or by applying classifications methods such as artificial neural networks, cellular neuronal networks, and support vector machines. less thanbrgreater than less thanbrgreater thanEPILAB proved to be an efficient tool for seizure prediction, and aims to be a way to communicate, evaluate, and compare results and data among the seizure prediction community.
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| 2. |
- Timmer, Stefan A J, et al.
(författare)
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Carriers of the hypertrophic cardiomyopathy MYBPC3 mutation are characterized by reduced myocardial efficiency in the absence of hypertrophy and microvascular dysfunction
- 2011
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Ingår i: European Journal of Heart Failure. - : Wiley. - 1388-9842 .- 1879-0844. ; 13:12, s. 1283-1289
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Tidskriftsartikel (refereegranskat)abstract
- AIMS:Next to left ventricular (LV) hypertrophy, hypertrophic cardiomyopathy (HCM) is characterized by microvascular dysfunction and reduced myocardial external efficiency (MEE). Insights into the presence of these abnormalities as early markers of disease are of clinical importance in risk stratification, and development of therapeutic approaches. Therefore, the aim was to investigate myocardial perfusion and energetics in genotype-positive, phenotype-negative HCM subjects (carriers).METHODS AND RESULTS:Fifteen carriers of an MYBPC3 mutation underwent [15O]water positron emission tomography (PET) to assess myocardial blood flow (MBF). [11C]acetate PET was performed to obtain myocardial oxygen consumption (MVO2). By use of cardiovascular magnetic resonance imaging, LV volumes and mass were defined to calculate MEE, i.e. the ratio between external work and MVO2. Eleven healthy, genotype-negative, family relatives underwent similar scanning protocols to serve as a control group. Left ventricular mass was comparable between carriers and controls (93 ± 25 vs. 99 ± 21 g, P= 0.85), as was MBF at rest (1.19 ± 0.34 vs. 1.18 ± 0.32 mL min−1 g−1, P= 0.92), and during hyperaemia (3.87 ± 0.75 vs. 3.96 ± 0.86 mL min−1 g−1, P= 0.77). Myocardial oxygen consumption averaged 0.137 ± 0.057 mL min−1 g−1 in carriers and was not significantly different from controls (0.125 ± 0.043 mL min−1 g−1, P= 0.29). Cardiac work, however, was slightly reduced in carriers (7398 ± 1384 vs. 9139 ± 2484 mmHg mL in controls, P= 0.08). As a consequence, MEE was significantly decreased in carriers (27 ± 10 vs. 36 ± 8% in controls, P= 0.02).CONCLUSION:Carriers display reduced myocardial work generation in relation to oxygen consumption, in the absence of hypertrophy and flow abnormalities. Hence, impaired myocardial energetics may constitute a primary component of HCM pathogenesis.
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| 3. |
- Timmer, S A J, et al.
(författare)
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Right ventricular energetics in patients with hypertrophic cardiomyopathy and the effect of alcohol septal ablation
- 2011
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Ingår i: Journal of Cardiac Failure. - : Elsevier BV. - 1071-9164 .- 1532-8414. ; 17:10, s. 827-831
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND:Diastolic dysfunction in hypertrophic cardiomyopathy (HCM) is accompanied by augmented left ventricular (LV) end-diastolic pressure, above all in the presence of LV outflow tract (LVOT) obstruction. Increased back-pressure may augment right ventricular (RV) afterload and induce an oxidative metabolic imbalance between the 2 ventricles. The aim was to study right-to-left ventricular oxidative metabolism in HCM and the effects of alcohol septal ablation (ASA).METHODS AND RESULTS:Twenty-one HCM patients were enrolled. Eleven healthy subjects served as a control group. Subjects underwent 2-dimensional echocardiography to assess LVOT gradient, left atrial size, and diastolic function. [11C]Acetate positron-emission tomography (PET) was performed to determine RVk2 and LVk2, as a noninvasive index of oxidative metabolism. Seven HCM patients with LVOT obstruction, scheduled to undergo ASA, were also studied 6 months after the procedure. RVk2 was higher in HCM patients than i control subjects (0.081 ± 0.021 min−1 vs. 0.061 ± 0.017 min−1; P = .05), whereas LVk2 was similar between groups. Consequently, RVk2/LVk2 was increased in the patients (0.85 ± 0.19 vs 0.59 ± 0.13; P = .004). In patients with obstructive HCM, ASA reduced RVk2 (0.085 ± 0.021 min−1 to 0.072 ± 0.022 min−1; P = .001). Inasmuch as LVk2 remained unaffected by the procedure, RVk2/LVk2 was decreased after ASA (0.66 ± 0.18; P = .03). The absolute change in LVOT gradient was related to the absolute change in RVk2 (r = 0.77; P = .044).CONCLUSIONS:In HCM patients, RV oxygen consumption is increased in relation to the LV. ASA reduces RV oxygen consumption in HCM patients with LVOT obstruction, suggesting that increased LV loading conditions and diastolic dysfunction play a predominant role in augmenting RV workload in these patients.
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