| 1. |
- Kronander, Håkan, et al.
(author)
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Analysis of ST/HR hysteresis improves long-term prognostic value of exercise ECG test.
- 2011
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In: International Journal of Cardiology. - : Elsevier BV. - 0167-5273 .- 1874-1754. ; 148:1, s. 64-9
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Journal article (peer-reviewed)abstract
- BACKGROUND: ST/HR hysteresis is one of the better diagnostic exercise ECG variables for coronary artery disease. This study evaluates the long-term prognostic value of ST/HR hysteresis in predicting acute myocardial infarction (AMI) and all-cause mortality in men and women. METHODS: The study population consisted of 8317 patients who had undergone routine exercise test on bicycle ergometer at one Swedish centre. Information on AMI and all-cause mortality was obtained from national Swedish registers covering a mean follow-up period of 9.5 years. RESULTS: The adjusted hazard ratio for AMI at a diagnostic cut point of ≤-20 µV for ST/HR hysteresis was 1.88 (95% CI, 1.62-2.17) in men and 2.31 (95% CI, 1.83-2.91) in women. For all-cause death the adjusted hazard ratio was 1.72 (95% CI, 1.52-1.96) in men and 1.90 (95% CI, 1.57-2.29) in women. The corresponding hazard ratios for ST-segment depression with horizontal or down-sloping ST-segment, ST-segment depression, ST/HR index, and ST/HR slope were lower. For comparison, the adjusted hazard ratio for AMI using maximal workload in percent of predicted was 2.02 (95% CI, 1.77-2.32) in men and 2.14 (95% CI, 1.71-2.67) in women. Area under the ROC curves for prediction of AMI was significantly larger using ST/HR hysteresis than using any of three other evaluated ECG indicators. CONCLUSIONS: ST/HR hysteresis appears to improve the prognostic ability of an exercise ECG test for AMI and all-cause mortality in a long-term perspective compared to conventional ST-segment and ST/HR indicators in both genders and clearly more markedly in women.
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| 2. |
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| 3. |
- Kronander, Håkan, et al.
(author)
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Diagnostic performance and partition values of exercise electrocardiographic variables in the detection of coronary artery disease - improved accuracy by using ST/HR hysteresis
- 2010
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In: Clinical Physiology and Functional Imaging. - 1475-0961 .- 1475-097X. ; 30:2, s. 98-106
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Journal article (peer-reviewed)abstract
- P>Exercise electrocardiography is widely used for initial identification of patients with coronary artery disease (CAD). This study compares the measurements of ST-segment changes during exercise and during early postexercise recovery in terms of diagnostic discrimination capacity and optimal partition values. Data from 1876 patients undergoing a routine bicycle exercise test were analysed. CAD was angiographically verified in 668 patients, and excluded by angiography (n = 119), myocardial scintigraphy (n = 250), and on clinical grounds (n = 839) in 1208 patients. Postexercise ST/HR hysteresis was calculated as normalized for heart rate (HR) ST/HR loop area during the first 3 min of recovery. ST/HR index was obtained by dividing the overall ST amplitude change during exercise by exercise-induced HR change, and ST/HR slope was calculated using linear regression analysis of ST/HR data pairs during exercise. ST-segment depression was measured during, and for 3 min after the exercise. Discriminating capacity of the methods was evaluated in terms of receiver operating characteristic areas and optimal partition values providing the combination of the best sensitivity and specificity were established. The best diagnostic discrimination was provided by ST/HR hysteresis at optimal partition value of -15 mu V, followed by postexercise ST amplitude measurements at gender-specific partition values of -10 to -90 mu V, ST/HR slope [partition value 2 center dot 4 mu V (beats/min)-1], ST/HR index [partition value 1 center dot 6 mu V (beats/min)-1], and ST-segment depression during exercise (partition value 70 mu V in men and 90 mu V in women). The results demonstrate that analysis of postexercise ST/HR hysteresis offers the most accurate and gender indifferent identification of patients with CAD.
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| 4. |
- Kronander, Håkan, et al.
(author)
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Exercise electrocardiography for diagnosis of coronary artery disease: impact of sampling rate on the diagnostic performance of ST/HR-loop based on data from early recovery phase
- 2007
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In: Clinical Physiology and Functionel Imaging. - 1475-0961. ; 28:2, s. 96-100
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Journal article (peer-reviewed)abstract
- Quantitative analysis of electrocardiographic ST-segment/heart rate relationship (ST/HR loop) during early recovery phase of exercise stress test provides a sensitive tool for the detection of coronary artery disease (CAD). This study evaluates the effect of data sampling frequency on the diagnostic performance of ST/HR loop in 1876 patients undergoing a routine exercise test on a bicycle ergometer. CAD was verified angiographically in 668 patients and excluded by coronary angiography (n = 119), myocardial scintigraphy (n = 250) and on clinical grounds (n = 839) in 1208 patients. The normalized ST/HR loop area was calculated in all cases by integration of ST-segment amplitude difference from the end of exercise to the end of the first 3 min of recovery period over HR and dividing the integral by the HR difference over the integration period. The effect of different sampling rates (one, two and five samples per minute) on the CAD discrimination ability of ST/HR loop area was subsequently evaluated using receiver operating characteristic (ROC) curves. Reduction in ST/HR data sampling frequency from two to one sample per minute resulted in a significantly decreased diagnostic performance of the ST/HR loop whereas no differences in CAD discrimination capacity were observed between sampling frequencies of two and five samples per minute. The choice of ST/HR data sampling frequency may have a significant impact on the CAD diagnostic ability of the ST/HR loop. The use of sampling frequency below two samples per minute results in a significantly diminished diagnostic performance, a fact that should be taken into consideration when employing ST/HR diagnostic procedures.
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| 5. |
- Kronander, Håkan, et al.
(author)
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Improved capacity of exercise electrocardiography in the detection of coronary artery disease by focusing on diagnostic variables during the early recovery phase
- 2005
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In: Journal of Electrocardiology. - : Elsevier BV. - 0022-0736 .- 1532-8430. ; 38:2, s. 130-138
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Journal article (peer-reviewed)abstract
- The temporal distribution of the diagnostic information for the detection of coronary artery disease (CAD) provided by exercise-induced electrocardiographic (ECG) ST-segment amplitude changes in different ECG leads in men and women has not been fully investigated. To shed further light in this area, 1877 electrocardiograms selected from 8322 patients undergoing a routine exercise test on a bicycle ergometer were evaluated. ST-segment amplitude and the difference between heart rate-matched recovery and exercise ST-segment amplitudes (ST/HR difference) were measured. Coronary artery disease was verified angiographically in 669 patients and excluded in 1208 patients by angiography (n = 119), by myocardial scintigraphy (n = 250), or on clinical grounds (n = 839). The diagnostic performance of the 2 ECG methods used was assessed by constructing receiver operating characteristic curves for each sampling point every 12 seconds during 10 minutes of recovery as well as the last 4 minutes of exercise for the ST-segment amplitude. ST-segment amplitude performed better after exercise than during exercise and best within the first 2 minutes of recovery. Its diagnostic ability did not differ from the ST-amplitude hysteresis assessed by the difference between recovery ST-segment amplitude and exercise ST-segment amplitude at matched heart rate. Both methods performed better in men and the diagnostic information appeared mainly in leads I, -aVR, II, V-4, V-5, and V-6. The best discrimination of CAD is provided by analysis of ST-segment amplitude changes in 6 specific leads early during the recovery phase. This information should be targeted by exercise ECG diagnostic methods.
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| 6. |
- Abgrall, N., et al.
(author)
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The large enriched germanium experiment for neutrinoless double beta decay (LEGEND)
- 2017
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In: AIP Conference Proceedings. - : Author(s). - 1551-7616 .- 0094-243X. ; 1894
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Conference paper (peer-reviewed)abstract
- The observation of neutrinoless double-beta decay (0νββ) would show that lepton number is violated, reveal that neu-trinos are Majorana particles, and provide information on neutrino mass. A discovery-capable experiment covering the inverted ordering region, with effective Majorana neutrino masses of 15 - 50 meV, will require a tonne-scale experiment with excellent energy resolution and extremely low backgrounds, at the level of ∼0.1 count /(FWHM·t·yr) in the region of the signal. The current generation 76Ge experiments GERDA and the Majorana Demonstrator, utilizing high purity Germanium detectors with an intrinsic energy resolution of 0.12%, have achieved the lowest backgrounds by over an order of magnitude in the 0νββ signal region of all 0νββ experiments. Building on this success, the LEGEND collaboration has been formed to pursue a tonne-scale 76Ge experiment. The collaboration aims to develop a phased 0νββ experimental program with discovery potential at a half-life approaching or at 1028 years, using existing resources as appropriate to expedite physics results.
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| 7. |
- Birmingham, Elina, et al.
(author)
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Exploring emotional expression recognition in aging adults using the Moving Window Technique
- 2018
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In: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 13:10
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Journal article (peer-reviewed)abstract
- Adult aging is associated with difficulties in recognizing negative facial expressions such as fear and anger. However, happiness and disgust recognition is generally found to be less affected. Eye-tracking studies indicate that the diagnostic features of fearful and angry faces are situated in the upper regions of the face (the eyes), and for happy and disgusted faces in the lower regions (nose and mouth). These studies also indicate age-differences in visual scanning behavior, suggesting a role for attention in emotion recognition deficits in older adults. However, because facial features can be processed extrafoveally, and expression recognition occurs rapidly, eye-tracking has been questioned as a measure of attention during emotion recognition. In this study, the Moving Window Technique (MWT) was used as an alternative to the conventional eye-tracking technology. By restricting the visual field to a moveable window, this technique provides a more direct measure of attention. We found a strong bias to explore the mouth across both age groups. Relative to young adults, older adults focused less on the left eye, and marginally more on the mouth and nose. Despite these different exploration patterns, older adults were most impaired in recognition accuracy for disgusted expressions. Correlation analysis revealed that among older adults, more mouth exploration was associated with faster recognition of both disgusted and happy expressions. As a whole, these findings suggest that in aging there are both attentional differences and perceptual deficits contributing to less accurate emotion recognition.
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| 8. |
- Brehmer, Yvonne, et al.
(author)
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Neural correlates of training-related working-memory gains in old age
- 2011
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In: NeuroImage. - : Elsevier BV. - 1053-8119 .- 1095-9572. ; 58:4, s. 1110-1120
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Journal article (peer-reviewed)abstract
- Working memory (WM) functioning declines in old age. Due to its impact on many higher-order cognitive functions, investigating whether training can modify WM performance has recently been of great interest. We examined the relationship between behavioral performance and neural activity following five weeks of intensive WM training in 23 healthy older adults (M = 63.7 years). 12 participants received adaptive training (i.e. individually adjusted task difficulty to bring individuals to their performance maximum), whereas the others served as active controls (i.e. fixed low-level practice). Brain activity was measured before and after training, using fMRI, while subjects performed a WM task under two difficulty conditions. Although there were no training-related changes in WM during scanning, neocortical brain activity decreased post training and these decreases were larger in the adaptive training group than in the controls under high WM load. This pattern suggests intervention-related increases in neural efficiency. Further, there were disproportionate gains in the adaptive training group in trained as well as in non-trained (i.e. attention, episodic memory) tasks assessed outside the scanner, indicating the efficacy of the training regimen. Critically, the degree of training-related changes in brain activity (i.e. neocortical decreases and subcortical increases) was related to the maximum gain score achieved during the intervention period. This relationship suggests that the decreased activity, but also specific activity increases, observed were functionally relevant.
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| 9. |
- Bäckman, Lars, et al.
(author)
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Dopamine D(1) receptors and age differences in brain activation during working memory
- 2011
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In: Neurobiology of Aging. - Fayetteville, N.Y : Elsevier. - 0197-4580 .- 1558-1497. ; 32:10, s. 1849-1856
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Journal article (peer-reviewed)abstract
- In an fMRI study, 20 younger and 20 healthy older adults were scanned while performing a spatial working-memory task under two levels of load. On a separate occasion, the same subjects underwent PET measurements using the radioligand [(11)C] SCH23390 to determine dopamine D(1) receptor binding potential (BP) in caudate nucleus and dorsolateral prefrontal cortex (DLPFC). The fMRI study revealed a significant load modulation of brain activity (higher load>lower load) in frontal and parietal regions for younger, but not older, adults. The PET measurements showed marked age-related reductions of D(1) BP in caudate and DLPFC. Statistical control of caudate and DLPFC D(1) binding eliminated the age-related reduction in load-dependent BOLD signal in left frontal cortex, and attenuated greatly the reduction in right frontal and left parietal cortex. These findings suggest that age-related alterations in dopaminergic neurotransmission may contribute to underrecruitment of task-relevant brain regions during working-memory performance in old age.
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| 10. |
- Cortes, Diana, et al.
(author)
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Age differences in judgments of attractiveness, likeability, and trustworthiness of faces
- 2016
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In: Program of SANS 2016. ; , s. 58-58
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Conference paper (other academic/artistic)abstract
- People constantly evaluate faces to obtain social information. However, the link between aging and social evaluation of faces is not well understood. Todorov and colleagues introduced a data-driven model defined by valence and dominance as the two main components underlying social judgments of faces. They also created a stimulus set consisting of computer-generated faces which systematically vary along various social dimensions (e.g., Todorov et al., 2013, Emotion, 13, 724-38). We utilized a selection of these facial stimuli to investigate age-related differences in judgments of the following dimensions: attractiveness, competence, dominance, extraversion, likeability, threat, and trustworthiness. Participants rated how well the faces represented the intended social dimensions on 9-point scales ranging from not at all to extremely well. Results from 71 younger (YA; mean age = 23.42 years) and 60 older adults (OA; mean age = 69.19 years) showed that OA evaluated untrustworthy faces as more trustworthy, dislikeable faces as more likeable, and unattractive faces as more attractive compared to YA. OA also evaluated attractive faces as more attractive compared to YA, whereas YA did rate likeable and trustworthy faces as more likeable and trustworthy than did OA. In summary, our findings showed that OA evaluated negative social features less negatively compared to YA. This suggests that older and younger persons may use different cues for social evaluation of faces, and is in line with prior research suggesting age-related decline in the ability to recognize negative emotion expressions.
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