Long-Term Lake Area Change and Its Relationship with Climate in the Endorheic Basins of the Tibetan Plateau

Lakes are sensitive indicators of climate change in the Tibetan Plateau (TP), which have shown high temporal and spatial variability in recent decades. The driving forces for the change are still not entirely clear. This study examined the area change of the lakes greater than 1 km2 in the endorheic basins of the Tibetan Plateau (EBTP) using Landsat images from 1990 to 2019, and analysed the relationships between lake area and local and large-scale climate variables at different geographic scales. The results show that lake area in the EBTP has increased significantly from 1990 to 2019 at a rate of 432.52 km2·year−1. In the past 30 years, lake area changes in the EBTP have mainly been affected by local climate variables such as precipitation and temperature. At a large scale, Indian Summer Monsoon (ISM) has correlations with lake area in western sub-regions in the Inner Basin (IB). While Atlantic Multidecadal Oscillation (AMO) has a significant connection with lake area, the North Atlantic Oscillation (NAO) does not. We also found that abnormal drought (rainfall) brought by the El Niño/La Niña events are significantly correlated with the lake area change in most sub-regions in the IB.

Worsened Tricuspid Regurgitation Following Pericardiectomy for Constrictive Pericarditis

Background: Worsening tricuspid regurgitation (TR) severity may occur after pericardiectomy surgery for constrictive pericarditis patients; however, its mechanisms and predictors are not well established. We evaluated the clinical characteristics, associated factors, and outcomes of worsening TR after pericardiectomy. Methods: Consecutive patients undergoing pericardiectomy for constrictive pericarditis without tricuspid valve surgery and with pre- and postoperative echocardiography available during 2000 to 2017 were retrospectively studied. Clinical, imaging, hemodynamic, and mortality characteristics were analyzed by those with and without worsening TR by at least one grade. Results: Among 381 patients (age 61 [17] years, 318 [83.5%] male), 193 (50.7%) had worsening TR post-operatively, and 75 died during the 2.5 (5.4) years follow-up. In univariable analysis, worsening TR was associated with a history of congestive heart failure (47.2% versus 31.9%, P =0.003), increased left atrial volume indexed (23 versus 20 mL/m 2 , P =0.020), reduced right ventricular fractional area change (47% versus 54%, P <0.001), and worsening mitral regurgitation (39.7% versus 16.6%, P <0.001). Worsened TR had a trend toward reduced survival during follow-up (log-rank P =0.080), especially those with worsened TR but no recovery of TR grade on subsequent echocardiography within the first year compared with those without worsened TR (log-rank P =0.02). In multivariable analysis, right ventricular fractional area change, left atrial volume indexed, left ventricular mass indexed, pulmonary artery systolic pressure, and right atrial pressure/pulmonary capillary wedge pressure ratio were most associated with worsened TR, while blood urea nitrogen, hematocrit, lateral and medial e’ tissue Doppler and heart rate were most associated with mortality during follow-up. Conclusions: Worsening TR severity was prevalent after pericardiectomy and had a trend toward reduced survival, especially if TR severity did not recover on subsequent echocardiography. Presence of parameters associated with worsened TR and reduced survival should alert clinicians to carefully manage these patients during follow-up.

Effect of interventional edge-to-edge repair in tricuspid regurgitation on ring dimensions

Background The concept of percutaneous tricuspid valve edge-to-edge repair (pTVR) is based on the connection of leaflets in the area of insufficiency using a coaptation device. By closing the coaptation device a considerable tractive force is applied on the leaflets, which might have an effect on the valve ring. Aim of the study was to examine the impact of device implantation on tricuspid ring dimensions. Methods During pTVR 3D zoom loops of tricuspid valve were acquired before and after clip placement using transoesophageal echocardiography. Measurements of TV ring dimensions included the following parameters: ring area (TV area), maximal diameter, minimal diameter, eccentricity index (Figure 1). Tenting area was derived from a four-chamber view of the valve. In addition, regurgitation severity was graded from 1+ to 5+ by measuring vena contracta area (VCA3D) in 3D full volume colour Doppler loop using multiplanar reconstruction. Right atrial (RA) and ventricular volumes (RVVd3D, RVVs3D) and function (RVEF3D) were assessed in a 3D full volume loop. Results The study population comprised 97 patients (age 78±6 years, 47 male), who underwent pTVR at our hospital. As expected cavity dimension correlated with TV area size (for RVVd3D r=0.51, p&lt;0.001 and for RA volume r=0.71, p&lt;0.001). The mean TV ring area was significantly reduced (ring area 8.53±2.23 cm2/m2BSA vs. 7.55±2.18 cm2/m2BSA, p&lt;0.001) and the ring shape became more oval (Eccentricity index 1.2±0.15 vs. 1.29±0.17, p&lt;0.001) after pTVR. The reduction of ring area (12±7%, range 0.7–28%) showed an only modest correlation to the number of implanted coaptation devices (r=0.30, p&lt;0.001) and percentage reduction of VCA3D (r=0.36, p&lt;0.001). In the patient group with a ring area change ≥12% a reduction to TR grade ≤2+ by pTVR was achieved in 83% of cases, whereas only 62% of patients reached moderate TR when area change was below 12%. Conclusion pTVR using coaptation devices reduces the ring area. This effect is related to the number of devices implanted. FUNDunding Acknowledgement Type of funding sources: None.

Long-Term Electrocardiographic and Echocardiographic Progression of Arrhythmogenic Right Ventricular Cardiomyopathy and Their Correlation With Ventricular Tachyarrhythmias

Background: Prior studies of structural and electrocardiographic changes in arrhythmogenic right ventricular (RV) cardiomyopathy and their role in predicting ventricular arrhythmias (ventricular tachycardia) have shown conflicting results. Methods: We reviewed 405 ECGs, 315 transthoracic echocardiographies, and 441 implantable cardioverter defibrillator interrogations in 64 arrhythmogenic RV cardiomyopathy patients (56% men, mean age [SD], 44.2 [14.6] years) over a mean follow-up of 10 (range, 2.3–19) years. Generalized estimating equations were used to identify the association between ECG abnormalities, clinical variables, and transthoracic echocardiographic measurements (>mild degree of tricuspid regurgitation, RV outflow tract diameter in parasternal long axis and short axis, RV end-diastolic area, fractional area change). Results: There was a 4.65 (95% CI, 0.51%–8.8%) increase in RV end-diastolic area, a 3.75 (95% CI, 1.17%–6.34%) decrease in fractional area change, and 1.9 (95% CI, 1.3–2.8) higher odds (odds ratio) of RV wall motion abnormality with every 5-year increase in age after patients’ first transthoracic echocardiography. >Mild tricuspid regurgitation was an independent predictor of RV enlargement and dysfunction (hazard ratio of >10% drop in fractional area change from baseline [95% CI], 3.51 [1.77–6.95] and hazard ratio of >10% increase in RV end-diastolic area from baseline [95% CI], 4.90 [2.52–9.52]). Patients with implantable cardioverter defibrillator were more likely to develop >mild tricuspid regurgitation and larger structural and functional disease progression. More pronounced increase in RV end-diastolic area was translated into higher rates of any ventricular tachycardia. Inferior T-wave inversions and sum of R waves (mm) in V1 to V3 were predictors of RV enlargement and dysfunction with the former also predicting risk of any ventricular tachycardia. Conclusions: Arrhythmogenic RV cardiomyopathy is a progressive disease. Tricuspid regurgitation is an independent predictor of structural disease progression, which may be exacerbated by use of a transvenous implantable cardioverter defibrillator lead.

Impact of rehabilitation and status area change on land cover and carbon storage in Paliyan Wildlife Reserve, Gunung Kidul, Indonesia

Puspanti A, Kusumandari A, Faida LRW, Sudaryatno. 2021. Impact of rehabilitation and status area change on land cover and carbon storage in Paliyan Wildlife Reserve, Gunung Kidul, Indonesia. Biodiversitas 22: 3964-3971. This study analyzed the land cover change and carbon storage after the rehabilitation of Paliyan forest. This study mainly focused on the forest status during 1999-2019, especially after establishing a wildlife reserve forest and after rehabilitation activity. We used a combination of canopy density model, carbon conversion, and changes of management-related data to analyze land cover classes in two decades of 1999-2009 and 2009-2019 representing the change in status of the area, rehabilitation, and management dynamics through the time. The result shows that at baseline (1999), the status was still production plantation forest dominated by non-forest/open land with the most carbon storage in plantation forest of 5463.04 tons of carbon. In the first decade, important events occurred such as continuing illegal logging until 2001; change of area status to wildlife reserve forest; and initiation of rehabilitation in 2003. There was an increase in non-forest areas during the first decade, and carbon storage decreased mostly in plantation forests with only 867.71 tons of carbon remaining. In the second decade, rehabilitation has shown a positive impact in increasing forested areas, and altered non-forest to the forested area dominated by open forest/mixed agriculture area, followed by plantation forest, and secondary forest. In this decade, the legality of the area status and rehabilitation activity underwent to be more advance. The carbon storage also shows the positive result with the most increase of storage in plantation forest of 4072.932 tons carbon, or almost 4.7 times higher than that in 2009. Total carbon storage in 2019 was 13257.50 tons, or almost three times higher than that in 2009. The rehabilitation required a longer period to achieve a more dense forest condition as in 2019 the area was still dominated by open forest or agriculture. The smallholder farmers and high dependency of the surrounding community manage the land to feed their livestock, impede the rehabilitation and restoration process, and de-escalate the transition from non-forest to forest resulted in the more vegetated area. This result is important for stakeholders for designing appropriate forest-related policies and supporting further rehabilitation strategies.

Defining the reference range for right ventricular systolic strain by echocardiography in healthy subjects: A meta-analysis

Background Right ventricular (RV) systolic strain has recently demonstrated prognostic value in various cardiovascular diseases. Despite this, the reference range including the lower limit of normal (LLN) and factors associated with RV strain measurements are not well-established. This meta-analysis aimed to determine the mean and LLN of two- (2D) and three-dimensional (3D) right ventricular global (RVGLS), free wall (RVFWLS) and interventricular septal wall (IVSLS) longitudinal strains in healthy individuals and factors that affect strain measurements. Methods In this meta-analysis, Pubmed, Embase and Cochrane databases were searched until 31 July 2020 for eligible studies reporting RVGLS, RVFWLS and/or IVSLS in at least 30 healthy subjects. We pooled the means and LLNs of RV strains by two- (2D) and three- (3D) dimensional echocardiography, and performed meta-regression analyses. Results From 788 articles screened, 45 eligible studies totaling 4439 healthy subjects were eligible for analysis. Pooled means and LLNs with 95% confidence intervals for 2D- RV strains were RVGLS -23.4% (-24.2%, -22.6%) and -16.4% (-17.3%, -15.5%) in 27 studies; RVFWLS -26.9% (-28.0%, -25.9%) and -18.0% (-19.2%, -16.9%) in 32 studies; and IVSLS –20.4% (-22.0%, -18.9%) and -11.5% (-13.6%, -9.6%) in 10 studies, and similar results for 3D- RV strains. Right ventricular fractional area change and vendor software were associated with 2D-RVGLS and RVFWLS means and LLNs. Conclusion We reported the pooled means and LLNs of RV systolic strains in healthy subjects, to define thresholds for abnormal, borderline and normal strains. Important factors associated with RV systolic strains include right ventricular fractional area change and vendor software.

Echocardiographic Assessment of Right Ventricular Function in Post Thrombolysed Acute Inferior Wall Infarction Patients with Angiographic Correlation

BACKGROUND A significant number of patients with acute Inferior wall infarction will have RV dysfunction and most of them have occlusion of either right or left circumflex coronary artery. But RV assessment is not done routinely in echocardiographic examination. Patients present with inferior wall myocardial infarction (IWMI) subsequently develop right ventricular myocardial infarction (RVMI) and have poor prognosis. In this study we wanted to evaluate the incidence of RVMI and the role of echocardiography in assessing RV function and its impact in predicting infarct related artery by angiographic analysis in acute IWMI after thrombolysis. METHODS 86 patients with acute IWMI after thrombolysis were randomly selected. Echocardiographic examination of RV function was performed within 72 hours after thrombolysis. We applied RV echo parameters like FAC (Fractional Area Change %), TAPSE (Tricuspid Annular Plane Systolic Excursion), RV S’ (RV Systolic Excursion Velocity) and MPI (Myocardial Performance Index) to assess RV function. 48 patients underwent coronary angiogram which included 10 patients with normal RV function, rest with RV dysfunction. RESULTS Among 86 patients, we compared 64 patients of RV dysfunction with 22 patients having normal function. Echo indices were significantly lower in RV dysfunction group. FAC ( 27 ± 5.95 vs 45 ± 5.4 ) TAPSE (8.5 ± 2.0 19.59 ± 2.8 ), RV S’ ( 5.78 ± 1.26 vs 17.2 ± 3.5 ) and RVMPI (0.22 ± 0.03 vs 0.57± 0.03). Angiographic analysis of 28 of 38 patients with RV dysfunction showed significant proximal lesion in RCA as compared to only 2 among 10 patients with normal RV function. CONCLUSIONS Conventional echo examination will underestimate RV dysfunction hence we applied echo parameters like FAC, TAPSE, RV S’ and RVMPI and a significant proportion of thrombolysed acute IWMI patients were found to have RV dysfunction and it was also helpful in the prediction of infarct related artery which would be predominantly a critical proximal RCA occlusion. KEY WORDS RVMI (Right Ventricular Myocardial Infarction), FAC (Fractional Area Change %), TAPSE (Tricuspid Annular Plane Systolic Excursion), RV S’ (RV Systolic Excursion Velocity) ,MPI (Myocardial Performance Index), IRA ( Infarct Related Artery)

Gulf of Alaska ice-marginal lake area change over the Landsat record and potential physical controls

Lakes in contact with glacier margins can impact glacier evolution as well as the downstream biophysical systems, flood hazard, and water resources. Recent work suggests positive feedbacks between glacier wastage and ice-marginal lake evolution, although precise physical controls are not well understood. Here, we quantify ice-marginal lake area change in understudied northwestern North America from 1984–2018 and investigate climatic, topographic, and glaciological influences on lake area change. We delineate time series of sampled lake perimeters (n=107 lakes) and find that regional lake area has increased 58 % in aggregate, with individual proglacial lakes growing by 1.28 km2 (125 %) and ice-dammed lakes shrinking by 0.04 km2 (−15 %) on average. A statistical investigation of climate reanalysis data suggests that changes in summer temperature and winter precipitation exert minimal direct influence on lake area change. Utilizing existing datasets of observed and modeled glacial characteristics, we find that large, wide glaciers with thick lake-adjacent ice are associated with the fastest rate of lake area change, particularly where they have been undergoing rapid mass loss in recent times. We observe a dichotomy in which large, low-elevation coastal proglacial lakes have changed most in absolute terms, while small, interior lakes at high elevation have changed most in relative terms. Generally, the fastest-changing lakes have not experienced the most dramatic temperature or precipitation change, nor are they associated with the highest rates of glacier mass loss. Our work suggests that, while climatic and glaciological factors must play some role in determining lake area change, the influence of a lake's specific geometry and topographic setting overrides these external controls.