| 1. |
- Axfors, Cathrine, et al.
(författare)
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Association between convalescent plasma treatment and mortality in COVID-19 : a collaborative systematic review and meta-analysis of randomized clinical trials
- 2021
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Ingår i: BMC Infectious Diseases. - : BioMed Central (BMC). - 1471-2334. ; 21:1
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Forskningsöversikt (refereegranskat)abstract
- Background: Convalescent plasma has been widely used to treat COVID-19 and is under investigation in numerous randomized clinical trials, but results are publicly available only for a small number of trials. The objective of this study was to assess the benefits of convalescent plasma treatment compared to placebo or no treatment and all-cause mortality in patients with COVID-19, using data from all available randomized clinical trials, including unpublished and ongoing trials (Open Science Framework, ). Methods: In this collaborative systematic review and meta-analysis, clinical trial registries (ClinicalTrials.gov, WHO International Clinical Trials Registry Platform), the Cochrane COVID-19 register, the LOVE database, and PubMed were searched until April 8, 2021. Investigators of trials registered by March 1, 2021, without published results were contacted via email. Eligible were ongoing, discontinued and completed randomized clinical trials that compared convalescent plasma with placebo or no treatment in COVID-19 patients, regardless of setting or treatment schedule. Aggregated mortality data were extracted from publications or provided by investigators of unpublished trials and combined using the Hartung-Knapp-Sidik-Jonkman random effects model. We investigated the contribution of unpublished trials to the overall evidence. Results: A total of 16,477 patients were included in 33 trials (20 unpublished with 3190 patients, 13 published with 13,287 patients). 32 trials enrolled only hospitalized patients (including 3 with only intensive care unit patients). Risk of bias was low for 29/33 trials. Of 8495 patients who received convalescent plasma, 1997 died (23%), and of 7982 control patients, 1952 died (24%). The combined risk ratio for all-cause mortality was 0.97 (95% confidence interval: 0.92; 1.02) with between-study heterogeneity not beyond chance (I-2 = 0%). The RECOVERY trial had 69.8% and the unpublished evidence 25.3% of the weight in the meta-analysis. Conclusions: Convalescent plasma treatment of patients with COVID-19 did not reduce all-cause mortality. These results provide strong evidence that convalescent plasma treatment for patients with COVID-19 should not be used outside of randomized trials. Evidence synthesis from collaborations among trial investigators can inform both evidence generation and evidence application in patient care.
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| 2. |
- Chaudhry, Uzma, et al.
(författare)
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Vectorcardiography Findings Are Associated with Recurrent Ventricular Arrhythmias and Mortality in Patients with Heart Failure Treated with Implantable Cardioverter-Defibrillator Device
- 2020
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Ingår i: Cardiology. - : S. Karger AG. - 0008-6312 .- 1421-9751. ; 145:12, s. 784-794
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Tidskriftsartikel (refereegranskat)abstract
- Background: There is a need for refined risk stratification of sudden cardiac death and prediction of ventricular arrhythmias to correctly identify patients who are expected to benefit the most from implantable cardioverter-defibrillator (ICD) therapy. Methods: We conducted a registry-based retrospective observational study on patients with either ischemic (ICMP) or nonischemic dilated cardiomyopathy (NICMP) treated with ICD between 2002 and 2013 at a tertiary referral center. We evaluated 3 vectorcardiography (VCG) indices; spatial QRS-T angle, QRS vector magnitude (QRSvm), and T-wave vector magnitude (Twvm), and their association with all-cause mortality and ventricular arrhythmias. The VCG indices were automatically computed from resting 12-lead electrocardiograms before ICD implantation. Results: 178 patients were included in the study; 53.4% had ICMP, 79.2% were male, and mean ejection fraction was 27.4%. During the follow-up (median 89 months), 40 patients (23%) died; 31% had appropriate ICD therapy. In multivariate analysis with dichotomized variables, QRS-T angle >152° and Twvm <0.38 mV were significantly associated with increased mortality: HR 2.64 (95% CI 1.14-6.12, p = 0.02) and HR 5.30 (95% CI 2.31-12.11, p < 0.001), respectively. QRSvm <1.54 mV was borderline significant with mortality outcome (p = 0.10). The composite score of all 3 VCG indices, a score of 3, conferred an increased risk of mortality (including heart failure mortality) in multivariate analysis: HR 13.80 (95% CI 3.44-55.39, p < 0.001). Conclusion: The spatial QRS-T angle and Twvm are emerging VCG indices which are independently associated with mortality in patients with reduced left ventricular ejection fraction due to ICMP or NICMP. Using a composite score of all 3 vector indices, a maximum score was associated with poor long-term survival.
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| 3. |
- Chazdon, Robin L., et al.
(författare)
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Carbon sequestration potential of second-growth forest regeneration in the Latin American tropics
- 2016
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Ingår i: Science Advances. - : American Association for the Advancement of Science (AAAS). - 2375-2548. ; 2:5
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Tidskriftsartikel (refereegranskat)abstract
- Regrowth of tropical secondary forests following complete or nearly complete removal of forest vegetation actively stores carbon in aboveground biomass, partially counterbalancing carbon emissions from deforestation, forest degradation, burning of fossil fuels, and other anthropogenic sources. We estimate the age and spatial extent of lowland second-growth forests in the Latin American tropics and model their potential aboveground carbon accumulation over four decades. Our model shows that, in 2008, second-growth forests (1 to 60 years old) covered 2.4 million km2 of land (28.1% of the total study area). Over 40 years, these lands can potentially accumulate a total aboveground carbon stock of 8.48 Pg C (petagrams of carbon) in aboveground biomass via low-cost natural regeneration or assisted regeneration, corresponding to a total CO2 sequestration of 31.09 Pg CO2. This total is equivalent to carbon emissions from fossil fuel use and industrial processes in all of Latin America and the Caribbean from 1993 to 2014. Ten countries account for 95% of this carbon storage potential, led by Brazil, Colombia, Mexico, and Venezuela. We model future land-use scenarios to guide national carbon mitigation policies. Permitting natural regeneration on 40% of lowland pastures potentially stores an additional 2.0 Pg C over 40 years. Our study provides information and maps to guide national-level forest-based carbon mitigation plans on the basis of estimated rates of natural regeneration and pasture abandonment. Coupled with avoided deforestation and sustainable forest management, natural regeneration of second-growth forests provides a low-cost mechanism that yields a high carbon sequestration potential with multiple benefits for biodiversity and ecosystem services.
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| 4. |
- Cortez, Daniel
(författare)
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Applications of Vectorcardiography for Diagnosis and Risk Stratification in Subpopulations at Risk for Life-Threatening Arrhythmias
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Introduction: Vectorcardiography, or 3-dimensional electrocardiography is a tool which can be used to identify subtle changes in the electrical forces of the heart, and which can be applied to atrial depolarization, ventricular depolarization and ventricular repolarization for prognostic and diagostic purposes. Methods: Kor’s regression-related and quasi orthogonal methods was used to derive vectorcardiographic parameters from the 12-lead electrocardiogram and applied to a cohort of cryptogenic stroke patients to assess atrial fibrillation, hypertrophic cardiomyopathy patients to assess for ventricular arrhythmias, applied with right-precordial directed quasi orthogonal method to arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVC/D) patients for diagnosis, and applied to ventricular repolarization only to patients with genotype-positive/phenotype-negative Long QT2 syndrome (KNCH2 mutation) to assess for cardiac events. Parametric and non-parameteric parameters were presented as mean ± standard deviation and median (1st to 3rd interquartile ranges). Pearson and Spearman correlation coefficients were used for parametric and non-parametric data, respectively. Odds ratios with univariate and multivariate analyses as well as hazard ratios and Kaplan-Meier curves are presented. P-values under 0.05 were represented as significant. Results: In cryptogenic stroke patients, first atrial fibrillation event was predicted by baseline P-wave duration divided by P-wave vector magnitude (p<0.05). In hypertrophic cardiomyopathy patients, the spatial peaks QRS-T angle differentiated sustained ventricular arrhythmias (VA) from no VA (P < 0.001) and at 124.1 degrees gave positive and negative predictive values and an odds ratio of 36.7%, 96.1%, and 14.2 (95% confidence interval: 3.1-65.6), respectively. Combined right precordial-directed parameters were able to identify ARVD/C patients who otherwise met criteria but did not meet any ECG-specfiic 2010 Taskforce criteria from controls with a positive predictive value of 90.0% and negative predictive value of 83.3%. In patients with genotype positive KCNH2 mutations, without prolongation of the QTc, when dichotomized by the median of 0.30 mV, a low T-wave vector magnitude (TwVM) was associated with elevated cardiac event risk compared to those with high TwVM (HR=2.55, 95%CI 1.07-6.04, p=0.034) and the genotype-negative family members (HR=2.64, 95%CI 1.64-4.24, p<0.001). Conclusion: Vector magnitudes and spatial angles, involving atrial and ventricular depolarization as well as ventricular repolarization, can be helpful in identifying disease as well as first-onset arrhythmia in subpopulations at risk for sudden death or stroke.
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| 5. |
- Cortez, Daniel, et al.
(författare)
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Atrial time and voltage dispersion are both needed to predict new-onset atrial fibrillation in ischemic stroke patients
- 2017
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Ingår i: BMC Cardiovascular Disorders. - : Springer Science and Business Media LLC. - 1471-2261. ; 17:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Atrial fibrillation (AF) is a known risk factor for ischemic stroke. Electrocardiographic predictors of AF in population studies such as the Framingham Heart Study, as well as in hypertensive patients have demonstrated a predictive value of the P-wave duration for development of AF. QRS vector magnitude has had a predictive value in ventricular arrhythmia development. We aimed to assess the value of the three-dimensional P-wave vector magnitude and its relationship to P-wave duration for prediction of new-onset AF after ischemic stroke. Methods: First-ever ischemic stroke patients without AF at inclusion in the Lund Stroke Register were included. Measurements of P wave duration (Pd), QRS duration, corrected QT interval, and PQ interval were performed automatically using the University of Glasgow 12-lead ECG analysis algorithm. The P-wave vector magnitude (Pvm) was calculated automatically as the square root of the sum of the squared P-wave magnitudes in leads V6, II and one half of the P-wave amplitude in V2 ( PV 6 2 + PII 2 + 0.5 PV 2 2 $$ \sqrt(PV(6)^2+(PII)^2+(\left((0.5)^(\ast )PV2\right))^2) $$ ), based on the P-wave magnitude (Pvm) as defined by the visually transformed Kors' Quasi-orthogonal method. Results: The median age was 73 (IQR 63-80) years at stroke onset (135 males, 92 females). Multivariate predictors of new-onset atrial fibrillation included age>65years, hypertension, and Pd/Pvm. A cut-off value of 870ms/mV gave sensitivity, specificity, positive and negative predictive values of 51, 79, 30 and 87%, respectively. The Pd/Pvm was the only ECG predictor of AF with a significant multivariate hazard ratio of 2.02 (95% CI 1.18 to 3.46, p=0.010). Conclusion: P-wave dispersion as measured by the Pd/Pvm was the only ECG parameter measured which independently predicted subsequent AF identification in a cohort of stroke patients. Further prospective studies in larger cohorts are needed to validate its clinical usefulness.
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| 6. |
- Cortez, Daniel, et al.
(författare)
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ECG-derived spatial QRS-T angle is strongly associated with hypertrophic cardiomyopathy
- 2017
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Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 0022-0736 .- 1532-8430. ; 50:2, s. 195-202
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: ECG-derived vectorcardiography (VCG) has diagnostic and prognostic value in various diseases. Hypertrophic cardiomyopathy (HCM), a genetic disease with unexplained left ventricular hypertrophy, is one of the most common causes of sudden cardiac death (SCD) in young persons. Genotype positive status is associated with increased risk of systolic dysfunction, heart failure, and (SCD). Herein, we aimed to determine the diagnostic utility of derived VCG parameters in a large cohort of genotyped HCM patients. Methods: Between 1997 and 2007, genetic testing was performed on 1053 unrelated patients with HCM. Of these, 967 had 12-lead ECGs suitable for computerized derivation of VCG parameters, including the spatial mean and peaks QRS-T angles, spatial ventricular gradient (SVG), spatial QRS, QT, and Tpeak-Tend (TpTe) intervals. ECGs were also evaluated using Seattle ECG criteria. Differences between HCM patients and healthy controls as well as between genotype positive versus genotype negative HCM patients were assessed. Results: Spatial peaks (129.3. ±. 26.4 vs.30.5. ±. 24.2 degrees) and spatial mean QRS-T angles (121.8. ±. 38.6 vs. 47.3. ±. 27.6 degrees) were significantly higher in patients with HCM than in controls (P. <. 0.001). The spatial peaks and mean QRS-T angles identified 94% and 84% of HCM patients, respectively, while Seattle criteria identified 70.7% of patients (P. <. 0.001). Genotype positive patients had higher spatial mean QRS-T angles, spatial TpTe (P. <. 0.001 respectively), spatial peaks QRS-T angles (P. =0.017) and lower SVG (P. <. 0.001) than genotype negative patients. Conclusions: ECG-derived spatial QRS-T angles can differentiate patients with HCM from controls and could provide a better tool than traditional Seattle criteria. Clinical usefulness of VCG to differentiate genotype-negative from genotype-positive patients has yet to be established.
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| 7. |
- Cortez, Daniel, et al.
(författare)
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In Hypertrophic Cardiomyopathy, the Spatial Peaks QRS-T Angle Identifies Those With Sustained Ventricular Arrhythmias
- 2016
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Ingår i: Clinical Cardiology. - : Wiley. - 0160-9289. ; 39:8, s. 459-463
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Tidskriftsartikel (refereegranskat)abstract
- Background: The spatial peaks QRS-T (SPQRS-T) angle differentiates hypertrophic cardiomyopathy (HCM) patients from controls. Increased angle confers arrhythmia risk in other populations. Hypothesis: We predict that the SPQRS-T angle will identify HCM patients with sustained ventricular arrhythmias (VAs) and those with New York Heart Association class III/IV heart failure. Methods: Corrected QT interval, QRS duration, and SPQRS-T angle were assessed in HCM patients with VAs (>30seconds) and those without VAs. Results: One hundred HCM patients (mean age, 32.7±17.2years) were assessed. Twenty patients had VAs. The corrected QT interval identified VA (P = 0.018) and at 460ms gave positive and negative predictive values of 28.6% and 83.3%, respectively, and an odds ratio of 2.0 (95% confidence interval: 0.7-5.6). The SPQRS-T angle differentiated VA from no VA (P <0.001) and at 124.1 degrees gave positive and negative predictive values and an odds ratio of 36.7%, 96.1%, and 14.2 (95% confidence interval: 3.1-65.6), respectively. Conclusions: The SPQRS-T angle best differentiated patients with VAs.
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| 8. |
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| 9. |
- Cortez, Daniel, et al.
(författare)
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Lower spatial QRS-T angle rules out sustained ventricular arrhythmias in children with hypertrophic cardiomyopathy
- 2017
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Ingår i: Cardiology in the Young. - 1047-9511. ; 27:2, s. 354-358
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: The spatial peaks QRS-T angle accurately distinguishes children with hypertrophic cardiomyopathy from their healthy counterparts. The spatial peaks QRS-T angle is also useful in risk stratification for ventricular arrhythmias. We hypothesised that the spatial peaks QRS-T angle would be useful for the prediction of ventricular arrhythmias in hypertrophic cardiomyopathy patients under 23 years of age. Methods: Corrected QT interval and spatial peaks QRS-T angles were retrospectively assessed in 133 paediatric hypertrophic cardiomyopathy patients (12.4±6.6 years) with versus without ventricular arrhythmias of 30 seconds or longer. Significance, positive/negative predictive values, and odds ratios were calculated based on receiver operating characteristic curve cut-off values. Results: In total, 10 patients with ventricular arrhythmias were identified. Although the corrected QT interval did not differentiate those with versus without ventricular arrhythmias, the spatial peaks QRS-T angle did (151.4±19.0 versus 116.8±42.6 degrees, respectively, p<0.001). At an optimal cut-off value (124.1 degrees), the positive and negative predictive values of the spatial peaks QRS-T angle were 15.4 and 100.0%, respectively, with an odds ratio of 25.9 (95% CI 1.5–452.2). Conclusion: In children with hypertrophic cardiomyopathy, the spatial peaks QRS-T angle is associated with ventricular arrhythmia burden with high negative predictive value and odds ratio.
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| 10. |
- Cortez, Daniel, et al.
(författare)
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Non-invasive electrocardiographic predictors of atrial arrhythmias in patients with the Fontan palliation
- 2017
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Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 0022-0736. ; 50:5, s. 576-583
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Tidskriftsartikel (refereegranskat)abstract
- Background: Fontan palliation patients are at risk for atrial arrhythmias post-operatively. This study aimed to evaluate whether differences in depolarization vector magnitude or spatial P-R angle can reliably predict atrial arrhythmias in patients who had undergone Fontan palliation. Methods: A total of 115 patients who had Fontan palliation and post-Fontan catheterization were included. Atrial arrhythmias were identified in 14 patients. Measurements of ECG parameters including QRS vector magnitude, P-R duration, spatial QRS-T angle and spatial P-R angle were performed, and compared between those with and without atrial arrhythmias. Results: Only the QRSvm independently differentiated those with and without atrial arrhythmias with multivariate HR of 0.743 (95% CI 0.581 to 0.951). Conclusion: In Fontan patients, the QRSvm was the only significant independent predictor of atrial arrhythmias.
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| 11. |
- Cortez, Daniel, et al.
(författare)
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Noninvasive predictors of perioperative atrial arrhythmias in patients with tetralogy of Fallot undergoing pulmonary valve replacement
- 2017
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Ingår i: Clinical Cardiology. - : Wiley. - 0160-9289. ; 40:8, s. 591-596
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Tidskriftsartikel (refereegranskat)abstract
- Background: Patients with tetralogy of Fallot (TOF) have increased risk of atrial arrhythmias. Hypothesis: A measure of atrial dispersion, the P-wave vector magnitude (Pvm), can identify patients at risk for perioperative atrial flutter (AFL) or intra-atrial re-entrant tachycardia (IART) in a large TOF cohort. Methods: We performed a blinded, retrospective analysis of 158 TOF patients undergoing pulmonary valve replacement between 1997 and 2015. History of AFL/IART was documented using electrocardiogram, Holter monitor, exercise stress test, implanted cardiac device, and electrophysiology study. P-R intervals, Pvm, QRS duration, and QRS vector magnitude were assessed from resting sinus-rhythm 12-lead electrocardiograms and identification of those with AFL/IART was determined. Results: Fourteen patients (8.9%) were found to have AFL/IART. Pvm, QRS duration, and QRS vector magnitude significantly differentiated those with AFL/IART from those without on univariate analysis: 0.09±0.04 vs 0.18±0.07 mV, 161.3±21.9 vs 137.7±31.4ms, and 1.2 (interquartile range, 1.0-1.2) vs 1.6 mV (1.0-2.3), respectively (P < 0.05 for each). The Pvm had the highest area under the ROC curve (0.88) and was the only significant predictor on multivariate analysis, with odds ratio of 0.02 (95% confidence interval: 0.01-0.53). P-R duration, MRI volumes, and right-heart hemodynamics did not significantly differentiate those with vs those without AFL/IART. Conclusions: In TOF patients undergoing pulmonary valve replacement, Pvm has significant value in predicting those with perioperative AFL/IART. These clinical features may help further evaluate TOF patients at risk for perioperative atrial arrhythmias. Prospective studies are warranted.
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| 12. |
- Cortez, Daniel, et al.
(författare)
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Noninvasive Predictors of Ventricular Arrhythmias in Patients With Tetralogy of Fallot Undergoing Pulmonary Valve Replacement
- 2017
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Ingår i: JACC: Clinical Electrophysiology. - : Elsevier BV. - 2405-500X. ; 3:2, s. 162-170
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: This study sought to test the hypothesis that a vectorcardiographic parameter, the QRS vector magnitude (QRSVm), can risk stratify those patients at risk for sustained spontaneous ventricular arrhythmias (VAs) or ventricular arrhythmia inducibility (VAI) in a large cohort of patients with tetralogy of Fallot (TOF). Background: Patients with TOF have an increased risk of VAs, but predicting those at risk can often be challenging. Methods: Blinded retrospective analyses of 177 TOF patients undergoing pulmonary valve replacement (PVR) between 1997 and 2015 were performed. VAI was evaluated by programmed electrical stimulation in 48 patients. QRS intervals and QRSVm voltage measurements were assessed from resting 12-lead electrocardiograms, and risk of VA was determined. Clinical characteristics, including imaging and cardiac catheterizations, were used for other modality comparisons. Results: Sustained spontaneous VA occurred in 12 patients and inducible VA in 18 patients. Age and QRSVm were significant univariate predictors of VA. QRSVm was the only independent predictor of VAI (p < 0.001). Using a root mean square QRS value of 1.24 mV, the positive and negative predictive values were 47.9% and 97.8%, respectively, for spontaneous sustained VA. For VAI, using a QRSVm cutoff of 1.31 mV, positive and negative predictive values were 63.0% and 95.3%, respectively. Conclusions: In TOF patients undergoing PVR, older age was associated with increased spontaneous VA risk. Lower QRSVm predicted spontaneous VA or VAI risk with high negative predictive values. QRSVm is the only independent predictor of VAI. These clinical features may help further risk stratify TOF patients requiring therapies to prevent sudden death.
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| 13. |
- Cortez, Daniel, et al.
(författare)
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Pediatric noncompaction patients with high spatial QRS-T angles are at increased risk for ventricular tachycardia
- 2019
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Ingår i: Annals of Noninvasive Electrocardiology. - : Wiley. - 1082-720X. ; 24:1
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Noncompaction cardiomyopathy (NCCM) patients may develop sustained ventricular arrhythmias (VA). Currently no known electrocardiogram (ECG) parameter has demonstrated predictive value for VA development. The spatial QRS-T angle has demonstrated ability to identify VA in other cardiomyopathy populations. Methods: A total of 39 patients with NCCM, defined by compact to non-compact ratio of >2.3 by magnetic resonance imaging, were assessed. The first ECG taken at time of MRI was assessed utilizing the heart rate, the QRS duration (QRSd), the corrected QT interval (QTc), and the spatial QRS-T angle (SPQRS-T angle, three-dimensional angle between the QRS and T-wave vectors) were assessed. Results: Eight patients developed VA (20.5%). Median time to event was 3 months (95% CI 1.0 to 24.0 months). There were no significant differences between baseline ejection fraction or fractional shortening. Baseline median heart rate, spatial QRS-T angles, and indexed left ventricular end-diastolic volumes were all significantly higher in patients with VA development (p-value <0.05). Only heart rate and the SPQRS-T angle had significant univariate hazard ratios (HR) for VA at 1.031/beat per minute (1.001–1.071) and at a cut-off of 147 degrees the SPQRS-T angle gave a hazard ratio of HR of 5.773 (95% CI 1.161 to 28.702). The multivariate hazard ratio was only significant for the SPQRS-T angle, 1.031/degree (1.001–1.066). Survival analysis by Kaplan-Meier yielded a significant difference at a cutoff of 147 degrees. Conclusion: The SPQRS-T angle identified those at risk for VA development. Future studies are warranted with larger populations of noncompaction patients.
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| 14. |
- Cortez, Daniel, et al.
(författare)
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Quantitative T-wave morphology assessment from surface ECG is linked with cardiac events risk in genotype-positive KCNH2 mutation carriers with normal QTc values
- 2019
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Ingår i: Journal of Cardiovascular Electrophysiology. - : Wiley. - 1045-3873 .- 1540-8167. ; 30:12, s. 2907-2913
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Long QT syndrome (LQTS) mutation carriers have elevated the risk of cardiac events even in the absence of QTc prolongation; however, mutation penetrance in patients with normal QTc may be reflected in abnormal T-wave shape, particularly in KCNH2 mutation carriers. We aimed to assess whether the magnitude of a three-dimensional T-wave vector (TwVM) will identify KCNH2-mutation carriers with normal QTc at risk for cardiac events. Methods: Adult LQT2 patients with QTc < 460 ms in men and <470 ms in women (n = 113, age 42 ± 16 years, 43% male) were compared with genotype-negative family members (n = 1007). The TwVM was calculated using T-wave amplitudes in leads V6, II, and V2 as the square root of (TV62 + TII2 + (0.5*TV2)2). Cox regression analysis adjusted for gender and time-dependent beta-blocker use was performed to assess cardiac event (CE) risk, defined as syncope, aborted cardiac arrest, implantable cardioverter-defibrillator therapy, or sudden death. Results: Dichotomized by median of 0.30 mV, lower TwVM was associated with elevated CE risk compared to those with high TwVM (HR = 2.95, 95% CI, 1.25-6.98, P =.014) and also remained significant after including sex and time-dependent beta-blocker usage in the Cox regression analysis (HR = 2.64, 95% CI, 1.64-4.24, P <.001). However, these associations were found only in women but not in men who had low event rates. Conclusion: T-wave morphology quantified as repolarization vector magnitude using T-wave amplitudes retrieved from standard 12-lead electrocardiogram predicts cardiac events risk in LQT2 women and appears useful for risk stratification of KCNH2-mutation carriers without QTc prolongation.
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| 15. |
- Cortez, Daniel, et al.
(författare)
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Right precordial-directed electrocardiographical markers identify arrhythmogenic right ventricular cardiomyopathy in the absence of conventional depolarization or repolarization abnormalities
- 2017
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Ingår i: BMC Cardiovascular Disorders. - : Springer Science and Business Media LLC. - 1471-2261. ; 17:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) carries a risk of sudden death. We aimed to assess whether vectorcardiographic (VCG) parameters directed toward the right heart and a measured angle of the S-wave would help differentiate ARVD/C with otherwise normal electrocardiograms from controls. Methods: Task Force 2010 definite ARVD/C criteria were met for all patients. Those who did not fulfill Task Force depolarization or repolarization criteria (-ECG) were compared with age and gender-matched control subjects. Electrocardiogram measures of a 3-dimentional spatial QRS-T angle, a right-precordial-directed orthogonal QRS-T (RPD) angle, a root mean square of the right sided depolarizing forces (RtRMS-QRS), QRS duration (QRSd) and the corrected QT interval (QTc), and a measured angle including the upslope and downslope of the S-wave (S-wave angle) were assessed. Results: Definite ARVD/C was present in 155 patients by 2010 Task Force criteria (41.7 ± 17.6 years, 65.2% male). -ECG ARVD/C patients (66 patients) were compared to 66 control patients (41.7 ± 17.6 years, 65.2% male). All parameters tested except the QRSd and QTc significantly differentiated -ECG ARVD/C from control patients (p < 0.004 to p < 0.001). The RPD angle and RtRMS-QRS best differentiated the groups. Combined, the 2 novel criteria gave 81.8% sensitivity, 90.9% specificity and odds ratio of 45.0 (95% confidence interval 15.8 to 128.2). Conclusion: ARVD/C disease process may lead to development of subtle ECG abnormalities that can be distinguishable using right-sided VCG or measured angle markers better than the spatial QRS-T angle, the QRSd or QTc, in the absence of Taskforce ECG criteria.
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| 16. |
- Cortez, Daniel, et al.
(författare)
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The S-wave angle identifies arrhythmogenic right ventricular cardiomyopathy in patients with electrocardiographically concealed disease phenotype
- 2018
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Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 0022-0736 .- 1532-8430. ; 51:6, s. 1003-1008
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Tidskriftsartikel (refereegranskat)abstract
- Background: Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) carries risk of sudden death. We hypothesize that the S-wave angle differentiates ARVD/C with otherwise normal electrocardiograms from controls. Materials and methods: All patients met Task Force 2010 definite ARVD/C criteria. ARVD/C patients without Task Force depolarization/repolarization criteria (−ECG) were compared to controls. Electrocardiogram measures of QRS duration, corrected QT interval, and measured angle between the upslope and downslope of the S-wave in V2, were assessed. Results: Definite ARVD/C was present in 155 patients (42.7 ± 17.3 years, 68.4%male). −ECG ARVD/C patients (66 patients) were compared to 66 control patients (41.8 ± 17.6 years, 65.2%male). Only the S-wave angle differentiated −ECG ARVD/C patients from controls (<0.001) with AU the ROC curve of 0.77 (95%CI 0.53 to 0.71) and odds ratio of 28.3 (95%CI 6.4 to 125.5). Conclusion: ARVD/C may lead to development of subtle ECG abnormalities distinguishable using the S-wave angle prior to development of 2010 Taskforce ECG criteria.
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| 17. |
- Cortez, Daniel, et al.
(författare)
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Vectorcardiography identifies patients with electrocardiographically concealed long QT syndrome
- 2017
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Ingår i: Heart Rhythm. - : Elsevier BV. - 1547-5271. ; 14:6, s. 894-899
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Tidskriftsartikel (refereegranskat)abstract
- Background Long QT syndrome (LQTS) and genotypic subtypes are associated with distinctive T-wave patterns, arrhythmogenic triggers, and corrected QT (QTc) interval risk associations. Twenty percent of patients with LQTS have normal QTc values, defined as electrographically concealed LQTS (ecLQTS). Vectorcardiography (VCG) has value for sudden cardiac death risk assessment. Objective The purpose of this study was to determine the use of VCG to identify patients with ecLQTS. Methods We performed a retrospective analysis in patients with ecLQTS with resting QTc values <440 ms. Computerized derivation of the spatial mean and peak QRS-T angles, QTpeak, Tpeak-Tend (angle between QRS and T-wave peak amplitudes in 3-dimensional space), and T-wave eigenvalues (TwEVs; amplitudes [in microvolts] for each of the first 4 TwEVs were derived from the 12-lead electrocardiogram) was performed. The results were compared with those for healthy controls. Intergenotype differences were analyzed. Results Of 610 patients with LQTS, 169 patients (28%) had ecLQTS (86 (51%) men; mean age 22 ± 16 years; mean QTc interval 422 ± 14 ms). There were 519 healthy controls (44% men; mean age 19.8 ± 13.8 years) with a mean QTc interval of 426 ± 28 ms. Among VCG parameters, QTpeak and TwEVs significantly differentiated patients with ecLQTS from controls (P ≤.01 for each) as well as differentiated KCNQ1-encoded type 1 LQTS (ecLQT1), KCNH2-encoded type 2 LQTS (ecLQT2), and SCN5A-encoded type 3 LQTS (ecLQT3) from controls (P <.01). ecLQT3 was differentiated from controls and ecLQT1 and ecLQT2 by the fourth TwEV (P <.01 for each). The fourth TwEV differentiated symptomatic patients with ecLQTS from asymptomatic patients with ecLQTS (P <.01). Conclusion ecLQTS can be distinguished from controls using QTpeak. ecLQT3 was best differentiated by the fourth TwEV. VCG may facilitate familial diagnostic anticipation of LQTS status before the completion of mutation-specific genetic testing even with normal resting QTc values.
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| 18. |
- Embert, Dirk, et al.
(författare)
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Priority areas for amphibian conservation in a neotropical megadiverse country : the need for alternative, non place based, conservation
- 2011
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Ingår i: Biodiversity and Conservation. - : Springer Science and Business Media LLC. - 0960-3115 .- 1572-9710. ; 20:7, s. 1557-1570
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Tidskriftsartikel (refereegranskat)abstract
- Amphibians constitute one of the most threatened species group worldwide. Because they are affected by various threats such as habitat destruction, chytrid fungus, climate change, invasive species and human use, different approaches are needed for their conservation. In this paper we examine patterns of alpha diversity, endemism and threatened species distributions of amphibians in Bolivia. We modeled distribution data using ecological niche modeling implemented with MaxEnt (Maximum Entropy Modeling). In contrast with previous studies, we validated each individual map with specialists. Important areas for amphibian conservation were defined by overlapping species richness, endemism richness and concentration of threatened species, and then excluding all unsuitable habitats. Our goal was to identify high-priority sites for the conservation of amphibians in Bolivia. We discuss a place-based strategy (identification of priority areas) and the need for further non place-based strategies. We highlight the importance of strengthening two existing protected areas that together host up to 40% of Bolivia's threatened amphibian species, and we propose alternative strategies such as ex situ conservation for those species not covered by the priority areas. Bolivia's General Directorate for Biodiversity and Protected Areas (in Spanish, Direccin General de Biodiversidad y Areas Protegidas (DGBAP)) and Bolivian experts are jointly using the here presented results to define a national strategy of amphibian conservation for safeguarding this important element of Bolivia's biodiversity.
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| 19. |
- Gei, Maga, et al.
(författare)
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Legume abundance along successional and rainfall gradients in Neotropical forests
- 2018
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Ingår i: Nature Ecology & Evolution. - : Springer Science and Business Media LLC. - 2397-334X. ; 2:7
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Tidskriftsartikel (refereegranskat)abstract
- The nutrient demands of regrowing tropical forests are partly satisfied by nitrogen-fixing legume trees, but our understanding of the abundance of those species is biased towards wet tropical regions. Here we show how the abundance of Leguminosae is affected by both recovery from disturbance and large-scale rainfall gradients through a synthesis of forest inventory plots from a network of 42 Neotropical forest chronosequences. During the first three decades of natural forest regeneration, legume basal area is twice as high in dry compared with wet secondary forests. The tremendous ecological success of legumes in recently disturbed, water-limited forests is likely to be related to both their reduced leaflet size and ability to fix N2, which together enhance legume drought tolerance and water-use efficiency. Earth system models should incorporate these large-scale successional and climatic patterns of legume dominance to provide more accurate estimates of the maximum potential for natural nitrogen fixation across tropical forests.
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| 20. |
- Jimenez, Erick, et al.
(författare)
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His Bundle and Left Bundle Pacing in Pediatrics and Congenital Heart Disease : A Single Center Experience
- 2020
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Ingår i: Pediatric Cardiology. - : Springer Science and Business Media LLC. - 0172-0643 .- 1432-1971. ; 41:7, s. 1425-1431
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Tidskriftsartikel (refereegranskat)abstract
- Long-term right ventricular pacing is associated with left ventricular dysfunction and cardiomyopathy, particularly in pediatric patients and those with congenital heart disease (CHD). Research has shown that pacing-induced cardiomyopathy can be reversed with nonselective or selective His bundle pacing in adults, however, the information available about the use of this type of therapy in pediatrics and CHD is scarce. We performed a retrospective chart review of all the cases of His or left bundle pacing at the University of Minnesota, division of Pediatric Cardiology from January of 2019 to April of 2020. Parametric data are presented as mean ± standard deviation. Non-parametric data are presented as median value with interquartile ranges. Eight patients, ages 8 to 18 years (median of 11.5) and weight from 21.5 to 81.6 kg (median of 40 kg) underwent this procedure successfully. The most common structural heart disease was a repaired peri-membranous ventricular septal defect. Three patients (37.5%) had selective and three (37.5%) had nonselective His bundle pacing, and two patients (25%) had left bundle pacing. There were two cases of pacing-induced cardiomyopathy and each had a 14% and 16% improvement of the ejection fraction after nonselective His bundle pacing. There were no procedural complications. Selective and nonselective His bundle, as well as left bundle pacing may be a feasible procedure in pediatric patients with and without CHD. This procedure may improve pacing-induced cardiomyopathy in this population.
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| 21. |
- Lind, Alexander, et al.
(författare)
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Childhood screening for type 1 diabetes comparing automated multiplex Antibody Detection by Agglutination-PCR (ADAP) with single plex islet autoantibody radiobinding assays
- 2024
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Ingår i: EBioMedicine. - : Elsevier. - 2352-3964. ; 104
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundTwo or more autoantibodies against either insulin (IAA), glutamic acid decarboxylase (GADA), islet antigen-2 (IA-2A) or zinc transporter 8 (ZnT8A) denote stage 1 (normoglycemia) or stage 2 (dysglycemia) type 1 diabetes prior to stage 3 type 1 diabetes. Automated multiplex Antibody Detection by Agglutination-PCR (ADAP) assays in two laboratories were compared to single plex radiobinding assays (RBA) to define threshold levels for diagnostic specificity and sensitivity.MethodsIAA, GADA, IA-2A and ZnT8A were analysed in 1504 (54% females) population based controls (PBC), 456 (55% females) doctor's office controls (DOC) and 535 (41% females) blood donor controls (BDC) as well as in 2300 (48% females) patients newly diagnosed (1–10 years of age) with stage 3 type 1 diabetes. The thresholds for autoantibody positivity were computed in 100 10-fold cross-validations to separate patients from controls either by maximizing the χ2-statistics (chisq) or using the 98th percentile of specificity (Spec98). Mean and 95% CI for threshold, sensitivity and specificity are presented.FindingsThe ADAP ROC curves of the four autoantibodies showed comparable AUC in the two ADAP laboratories and were higher than RBA. Detection of two or more autoantibodies using chisq showed 0.97 (0.95, 0.99) sensitivity and 0.94 (0.91, 0.97) specificity in ADAP compared to 0.90 (0.88, 0.95) sensitivity and 0.97 (0.94, 0.98) specificity in RBA. Using Spec98, ADAP showed 0.92 (0.89, 0.95) sensitivity and 0.99 (0.98, 1.00) specificity compared to 0.89 (0.77, 0.86) sensitivity and 1.00 (0.99, 1.00) specificity in the RBA. The diagnostic sensitivity and specificity were higher in PBC compared to DOC and BDC.InterpretationADAP was comparable in two laboratories, both comparable to or better than RBA, to define threshold levels for two or more autoantibodies to stage type 1 diabetes.
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| 22. |
- Lind, Alexander, et al.
(författare)
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Multiplex agglutination-PCR (ADAP) autoantibody assays compared to radiobinding autoantibodies in type 1 diabetes and celiac disease
- 2022
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Ingår i: Journal of Immunological Methods. - : Elsevier BV. - 1872-7905 .- 0022-1759. ; 506
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Tidskriftsartikel (refereegranskat)abstract
- Multiplex Antibody-Detection by Agglutination-PCR (ADAP) assay was compared to singleplex standard radiobinding assays (RBA) to detect autoantibodies against insulin (IAA), GAD65 (GADA), islet antigen-2 (IA-2A), ZnT8 (ZnT8A) and tissue transglutaminase (TGA). Serum samples from 272 (114F/158M), 15-73 years of age healthy controls and 227 (109F/118M) newly diagnosed type 1 diabetes children, 1-11 years of age, were analyzed in both assay systems.The original WHO standard 97/550 and in-house reference standards for RBA were compared to ADAP. The ADAP and RBA generated parallel reference standards in all assays except TGA. Lower detection limits were observed in the ADAP assay for GADA,IAA and ZnT8A, markedly for TGA, but not for IA-2A. The Receiver Operating Characteristics (ROC) curve AUC analyses for pairwise comparison of ADAP with RBA showed no difference for GADA (n.s.), ADAP greater AUC for IAA (p = 0.005), RBA greater AUC for IA-2A (p = 0.0004) and ZnT8A (p < 0.0001) while ADAP TGA had a greater AUC compared to both RBA TGA-IgG (p < 0.0001) and TGA-IgA (p < 0.0001) . These data suggest that the ADAP and RBA assays are comparable with equal performance for GADA, better ADAP performance for IAA while the RBA showed better performance in both IA-2A and ZnT8A associated with greater heterogeneity in autoantibody levels. The simultaneous analysis of 5 different autoantibodies by ADAP in sample volume reduced to only 4 μL and at an increased lower detection limit in all assays except IA-2A makes the ADAP automated autoantibody assay a distinct advantage for high throughput screening.
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| 23. |
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| 24. |
- Poorter, Lourens, et al.
(författare)
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Wet and dry tropical forests show opposite successional pathways in wood density but converge over time
- 2019
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Ingår i: Nature Ecology & Evolution. - : Nature Publishing Group. - 2397-334X. ; 3:6, s. 928-934
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Tidskriftsartikel (refereegranskat)abstract
- Tropical forests are converted at an alarming rate for agricultural use and pastureland, but also regrow naturally through secondary succession. For successful forest restoration, it is essential to understand the mechanisms of secondary succession. These mechanisms may vary across forest types, but analyses across broad spatial scales are lacking. Here, we analyse forest recovery using 1,403 plots that differ in age since agricultural abandonment from 50 sites across the Neotropics. We analyse changes in community composition using species-specific stem wood density (WD), which is a key trait for plant growth, survival and forest carbon storage. In wet forest, succession proceeds from low towards high community WD (acquisitive towards conservative trait values), in line with standard successional theory. However, in dry forest, succession proceeds from high towards low community WD (conservative towards acquisitive trait values), probably because high WD reflects drought tolerance in harsh early successional environments. Dry season intensity drives WD recovery by influencing the start and trajectory of succession, resulting in convergence of the community WD over time as vegetation cover builds up. These ecological insights can be used to improve species selection for reforestation. Reforestation species selected to establish a first protective canopy layer should, among other criteria, ideally have a similar WD to the early successional communities that dominate under the prevailing macroclimatic conditions.
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| 25. |
- Sharma, Nandita, et al.
(författare)
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High burden of premature ventricular contractions in structurally normal hearts : To worry or not in pediatric patients?
- 2019
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Ingår i: Annals of Noninvasive Electrocardiology. - : Wiley. - 1082-720X .- 1542-474X. ; 24:6
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Tidskriftsartikel (refereegranskat)abstract
- Background: There is paucity of data regarding the significance of high percentage of premature ventricular contractions (PVCs) in healthy children and their impact on left ventricular (LV) function and the risk of ventricular arrhythmias. The purpose of this study was to assess the prevalence of LV systolic dysfunction in children with frequent PVCs and determine whether PVC characteristics were predictive of LV dysfunction. Methods: We performed a single-center retrospective review to examine the prevalence of PVC-induced cardiomyopathy and natural history of PVC burden in children with frequent PVCs. Children aged 6 months–21 years with PVCs noted on 24-hr Holter monitoring studies were enrolled. The four categories included those with a PVC burden of >10%, 10%–20%, and those with more than 20% PVC burden. Results: A total of 134 children were included, 65 with more than 10% PVCs and 31 with more than 20% PVCs. Median age of the patients was 10.5 years (IQR 6.1–14.8 years), with 79 males (54.5%). Median PVC burden was 8.7% (IQR 4.2%–16.9%) with median follow-up of 2.8 years (IQR 1.2–4.6 years). During 2.8 years (1.3–4.3 years) of follow-up, the PVC burden decreased by 67% of baseline PVC burden in those who did not undergo any intervention. There were no deaths. Conclusion: PVCs in children with structurally normal hearts are associated with a relatively benign course, with trend toward spontaneous resolution.
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| 26. |
- Siddeek, Hani, et al.
(författare)
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AVNRT captured by Apple Watch Series 4 : Can the Apple watch be used as an event monitor?
- 2020
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Ingår i: Annals of Noninvasive Electrocardiology. - : Wiley. - 1082-720X .- 1542-474X. ; 25:5
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Tidskriftsartikel (refereegranskat)abstract
- Wrist-worn devices are popular for heart rate monitoring, including use of photoplethysmography. The Apple Watch series 4 can identify atrial fibrillation. We describe a case of identification re-entrant supraventricular tachycardia not identified by outpatient rhythm monitoring, however, was identified by the Apple Watch series 4, which lead to electrophysiology study and successful ablation of atrioventricular nodal re-entrant tachycardia.
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| 27. |
- Siddeek, Hani, et al.
(författare)
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Pediatric Micra leadless pacemaker implantation via the internal jugular and femoral vein : A single-center, US experience
- 2021
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Ingår i: Future Cardiology. - : Future Medicine Ltd. - 1479-6678 .- 1744-8298. ; 17:6, s. 1116-1122
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Tidskriftsartikel (refereegranskat)abstract
- Background: In the pediatric population, conventional transvenous and epicardial pacemaker systems carry complications such as lead distortion due to growth/activity, in addition to other lead/pocket complications. Materials & methods: A retrospective review of pediatric leadless pacing at the University of Minnesota Masonic Children's Hospital from 2018 to 2020 was performed. Rationale for pacing, demographics of patients, thresholds and longevity of devices were recorded. Results: Seven leadless pacemaker insertions and one removal were performed successfully, in patients weighing between 19 kg and 58 kg. Three patients had Micra implantation via internal jugular vein. One pericardial effusion occurred perioperatively in a 19 kg patient with baseline thrombocytopenia, sideroblastic anemia and Pearson Marrow Pancreas syndrome. Conclusion: Leadless pacemaker implantation/early retrieval is feasible in pediatric patients.
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| 28. |
- Tran, Tuong Vi, et al.
(författare)
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Clinical Application of the QRS-T Angle for the Prediction of Ventricular Arrhythmias in Patients with the Fontan Palliation
- 2017
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Ingår i: Pediatric Cardiology. - : Springer Science and Business Media LLC. - 0172-0643 .- 1432-1971. ; 38:5, s. 1049-1056
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Tidskriftsartikel (refereegranskat)abstract
- Fontan palliation patients are at risk for ventricular arrhythmias post-operatively. This study aimed to evaluate whether differences in the spatial QRS-T angle can reliably predict ventricular arrhythmias in patients who had undergone Fontan palliation. A total of 117 patients who had the Fontan palliation and post-Fontan catheterization were included. Ventricular arrhythmias were identified in nine patients. Measurements of ECG parameters including QRS vector magnitude, QRS duration, corrected QT interval, and spatial peaks QRS-T angles were performed, and compared between those with and without ventricular arrhythmias. The only ECG parameter to distinguish those with versus those without VA was the SPQRS-T angle (p < 0.001), which at a cut-off value of 102.9° gave sensitivity, specificity, positive and negative predictive values of 100.0, 57.0, 17.6 and 100.0%, respectively. Only the spatial peaks QRS-T angle differentiated those with and without ventricular arrhythmia development with a univariate HR 1.237 (95% CI 1.021–1.500) and a multivariate HR of 1.032 (1.009–1.056) when catheter measured parameters were taken into account. In Fontan patients, the spatial peaks QRS-T angle is a significant independent predictor of ventricular arrhythmias. Clinical usefulness of this parameter remains to be seen and should be tested prospectively.
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