Urban Food Systems: How Regionalization Can Contribute to Climate Change Mitigation.

Cities will play a key role in the grand challenge of nourishing a growing global population, because, due to their population density, they set the demand. To ensure that food systems are sustainable, as well as nourishing, one solution often suggested is to shorten their supply chains toward a regional rather than a global basis. While such regional systems may have a range of costs and benefits, we investigate the mitigation potential of regionalized urban food systems by examining the greenhouse gas emissions associated with food transport. Using data on food consumption for 7108 urban administrative units (UAUs), we simulate total transport emissions for both regionalized and globalized supply chains. In regionalized systems, the UAUs' demands are fulfilled by peripheral food production, whereas to simulate global supply chains, food demand is met from an international pool (where the origin can be any location globally). We estimate that regionalized systems could reduce current emissions from food transport. However, because longer supply chains benefit from maximizing comparative advantage, this emission reduction would require closing yield gaps, reducing food waste, shifting toward diversified farming, and consuming seasonal produce. Regionalization of food systems will be an essential component to limit global warming to well below 2 °C in the future.

Agro-ecological suitability assessment of Chinese Medicinal Yam under future climate change.

Chinese Medicinal Yam (CMY) has been prescribed as medicinal food for thousand years in China by Traditional Chinese Medicine (TCM) practitioners. Its medical benefits include nourishing the stomach and spleen to improve digestion, replenishing lung and kidney, etc., according to the TCM literature. As living standard rises and public health awareness improves in recent years, the potential medicinal benefits of CMY have attracted increasing attention in China. It has been found that the observed climate change in last several decades, together with the change in economic structure, has driven significant shift in the pattern of the traditional CMY planting areas. To identify suitable planting area for CMY in the near future is critical for ensuring the quality and supply quantity of CMY, guiding the layout of CMY industry, and safeguarding the sustainable development of CMY resources for public health. In this study, we first collect 30-year records of CMY varieties and their corresponding phenology and agro-meteorological observations. We then consolidate these data and use them to enrich and update the eco-physiological parameters of CMY in the agro-ecological zone (AEZ) model. The updated CMY varieties and AEZ model are validated using the historical planting area and production under observed climate conditions. After the successful validation, we use the updated AEZ model to simulate the potential yield of CMY and identify the suitable planting regions under future climate projections in China. This study shows that regions with high ecological similarity to the genuine and core producing areas of CMY mainly distribute in eastern Henan, southeastern Hebei, and western Shandong. The climate suitability of these areas will be improved due to global warming in the next 50 years, and therefore, they will continue to be the most suitable CMY planting regions.

Severe heart failure and the need for mechanical circulatory support and heart transplantation in pediatric patients with myocarditis: Results from the prospective multicenter registry "MYKKE".

Myocarditis represents an important cause for acute heart failure. MYKKE, a prospective multicenter registry of pediatric patients with myocarditis, aims to gain knowledge on courses, diagnostics, and therapy of pediatric myocarditis. The role of mechanical circulatory support (MCS) in children with severe heart failure and myocarditis is unclear. The aim of this study was to determine characteristics and outcome of patients with severe heart failure requiring MCS and/or heart transplantation. The MYKKE cohort between September 2013 and 2016 was analyzed. A total of 195 patients were prospectively enrolled by 17 German hospitals. Twenty-eight patients (14%) received MCS (median 1.5 years), more frequently in the youngest age group (0-2 years) than in the older groups (P < 0.001; 2-12 and 13-18 years). In the MCS group, 50% received a VAD, 36% ECMO, and 14% both, with a survival rate of 79%. The weaning rate was 43% (12/28). Nine (32%) patients were transplanted, one had ongoing support, and six (21%) died. Histology was positive for myocarditis in 63% of the MCS group. Patients within the whole cohort with age <2 years and/or ejection fraction <30% had a significantly worse survival with high risk for MCS, transplantation, and death (P < 0.001). Myocarditis represents a life-threatening disease with an overall mortality of 4.6% in this cohort. The fulminant form more often affected the youngest, leading to significantly higher rate of MCS, transplantation, and mortality. MCS represents an important and life-saving therapeutic option in children with myocarditis with a weaning rate of 43%.

Increase in grain production potential of China under climate change.

The rapid growth of China's demand for grains is expected to continue in the coming decades, largely as a result of the increasing feed demand to produce protein-rich food. This leads to a great concern on future supply potentials of Chinese agriculture under climate change and the extent of China's dependence on world food markets. While the existing literature in both agronomy and climate economics indicates a dominance of the adverse impacts of climate change on rice, wheat, and maize yields, there is a lack of study to assess changes in multi-cropping opportunities induced by climate change. Multi-cropping benefits crop production by harvesting more than once per year from a given plot. To address this important gap, we established a procedure within the agro-ecological zones (AEZ) modeling framework to assess future spatial shifts of multi-cropping conditions. The assessment was based on an ensemble of five general circulation models under four representative concentration pathway scenarios in the phase five of coupled model inter-comparison project and accounted for the water scarcity constraints. The results show significant northward extensions of single-, double-, and triple-cropping zones in the future which would provide good opportunities for crop-rotation-based adaptation. The increasing multi-cropping opportunities would be able to boost the annual grain production potential by an average scale of 89(±49) Mt at the current irrigation efficiency and 143(±46) Mt at the modernized irrigation efficiency with improvement between the baseline (1981-2010) and the mid-21st century (2041-2070).

Clinical characteristics and outcome of biopsy-proven myocarditis in children - Results of the German prospective multicentre registry "MYKKE".

BACKGROUND: Heart failure (HF) due to myocarditis might not respond in the same way to standard therapy as HF due to other aetiologies. The aim of this study was to investigate the value of endomyocardial biopsies (EMB) for clinical decision-making and its relation to the outcome of paediatric patients with myocarditis. METHODS: Clinical and EMB data of children with myocarditis collected for the MYKKE-registry between 2013 and 2020 from 23 centres were analysed. EMB studies included histology, immunohistology, and molecular pathology. The occurrence of major adverse cardiac events (MACE) including mechanical circulatory support (MCS), heart transplantation, and/or death was defined as a combined endpoint. RESULTS: Myocarditis was diagnosed in 209/260 patients: 64% healing/chronic lymphocytic myocarditis, 23% acute lymphocytic myocarditis (AM), 14% healed myocarditis, no giant cell myocarditis. The median age was 12.8 (1.4-15.9) years. Time from symptom-onset to EMB was 11.0 (4.0-29.0) days. Children with AM and high amounts of mononuclear cell infiltrates were significantly younger with signs of HF compared to those with healing/chronic or healed myocarditis. Myocardial viral DNA/RNA detection had no significant effect on outcome. The worst event-free survival was seen in patients with healing/chronic myocarditis (24%), followed by acute (31%) and healed myocarditis (58%, p = 0.294). A weaning rate of 64% from MCS was found in AM. CONCLUSIONS: EMB provides important information on the type and stage of myocardial inflammation and supports further decision-making. Children with fulminant clinical presentation, high amounts of mononuclear cell infiltrates or healing/chronic inflammation and young age have the highest risk for MACE.

A novel method of hybrid intraoperative catheter-based closure of ventricular septal defects using the Amplatzer® PDA occluder.

BACKGROUND: In five patients, an apical muscular septal defect was closed in a hybrid approach using the Amplatzer® duct occluder during open heart surgery, whereas concomitant defects were treated surgically. In addition to their different heart defects that needed surgery, all had a muscular ventricular septal defect in the apex of the heart, poorly accessible for traditional, surgical approach. We describe the method and outcome in these patients. METHODS: The tip of a forceps was advanced from the left into the right ventricle through the ventricular septal defect. The delivery sheath was caught under visual control in the right ventricle and pulled back into the left ventricle. The disc was developed and pulled back until it was felt tugging at the septum. Then the core was developed. The end of the device was visible in the right ventricle and was secured with a Prolene® suture. RESULTS: The procedures were event-free. During early follow-up there were either no or only insignificant shunts in the region of the prior trabecular defects in four patients. The unsatisfactory result in the last patient was caused by inaccurate preoperative assessment. CONCLUSION: The method seems valuable in patients in need of other intracardiac surgery.

Device closure of ventricular septal defects by hybrid procedures: a multicenter retrospective study.

OBJECTIVE: This study reports on the feasibility, efficacy, and outcome of hybrid procedures to close ventricular septal defects (VSD), reflecting the experience of 11 centers in Germany, Austria, and Switzerland. BACKGROUND: Beating heart closure of VSD has attracted interest in small infants, complex anomalies and postinfarction scenarios where patients are at high risk during surgery. Perventricular or intraoperative device placement allows access to the lesions where percutaneous delivery is limited. METHODS: Between December 2001 and April 2009, placement of Amplatzer septal occluders was attempted in 26 patients. The defects were located in the perimembranous (n = 5) and muscular septum (n = 21). In 20 patients, a perventricular approach was used, and, in six, the occluders were placed under direct visualization being part of a complex heart surgery. RESULTS: In 23 of 26 procedures, device placement was successful (88.5%). The mean defect size was 7.8 mm (range, 3.5-20). The occluder types were perimembranous VSD occluder (n = 4), muscular VSD occluder (n = 20), postinfarct VSD occluder (n = 1), and ASD occluder (n = 1) with a ratio device/defect of 0.9-2.4 (median 1.15). Device removal was necessary in three due to arrhythmia, malpositioning, and additional defects. Pericardial effusion occurred once. In the remaining 22 patients, there were no procedure or device-related complications. During mean follow up of 1.4 years (range, 1 day-3.9 years), a residual shunt that was more than trivial was observed in one patient out of 21 successful procedures. CONCLUSIONS: Perventricular and intraoperative device closure of VSD is as effective as a surgical patch and averts the increased morbidity of conventional surgical repair in a subgroup of high-risk patients.

Catheter based closure of ventricular septal defects.

BACKGROUND: Catheter based treatment for heart diseases is increasing. Rikshospitalet has been the leading force in Norway to introduce such methods. We present the results of such treatment for different defects in the ventricular septum (VSD). MATERIAL AND METHODS: Thirty seven patients catheterised with the purpose of closing a VSD with catheter-based techniques were reviewed. Two patients had VSD after myocardial infarction, ten had muscular and 25 had perimembranous VSD. RESULTS: In two patients with perimembranous VSD the attempts were unsuccessful. One patient with muscular and one with post-infarction-VSD had to be catheterised twice. All perimembranous VSD, except one, were completely closed (96%). Complications included one patient who developed a complete heart block requiring a pacemaker, and another who got an intermittent left bundle branch block. Of the muscular VSD four (40%) closed completely, but the residual defects were small and clinically insignificant. None of them developed haemolysis. Both patients with post-infarction-VSD had small leaks, but improved clinically. CONCLUSION: Catheter-based closure of VSD is a good alternative to open heart surgery. At present our own and the reported incidence of complete AV blocks lead us to be cautious when recommending closure of perimembranous VSD.

Catheter-based treatment with the Amplatzer devices in alien positions.

OBJECTIVE: Case reports of patients with Amplatzer devices used in positions they have not been designed for have repeatedly been published. BACKGROUND: We pooled our results to review the array of such interventions. METHODS: Retrospective study of twelve patients presented with eleven different problems: Two patients had hepatoatrial communication after Fontan's operation, two had different types of fistulae, two had surgical shunts, two had different anomalous systemic venous drainage, and two had an open arterial duct, one huge and hypertensive, the other with a very shallow ampulla. Finally, in one, a pulmonary artery was closed as a preparation for a bidirectional cavo-pulmonary anastomosis. RESULTS: All communications were completely closed. As only complication a lesion of the anonymous vein causing haematothorax was noted when trying to access through a Gore-Tex membrane after puncture. CONCLUSIONS: Such applications of Amplatzer devices in alien positions are estimated to be needed in 1 in 5-700 catheterizations. The results are good and the complications few.

Off-pump mitral valved stent implantation: comparison of apical and subannular fixation techniques.

OBJECTIVES: A large cohort of patients suffering from severe mitral regurgitation does not meet the indications for conventional surgery and would greatly benefit from a transcatheter approach in the beating heart. Consequently, off-pump transcatheter mitral valve procedures have been the focus of recent research. The aim of this study was the in vivo evaluation and comparison of subannular versus apical fixation of mitral valved stents to show the feasibility of subannular anchorage. METHODS: Twenty-two pigs received a self-expanding valved stent in the mitral position in an off-pump procedure. The first design (design AP: n = 12) was anchored apically and served as the control group. The second design (design SA: n = 10) included additional sub-annular fixation elements. Echocardiographic and haemodynamic evaluations were conducted before and 1 h after stent implantation. RESULTS: Haemodynamic stability was achieved, and the capillary wedge pressure was within a normal range (AP: 11 ± 4 mmHg, SA: 9 ± 4 mmHg). Paravalvular leakages were trace or less in 19 of 20 cases. The mean gradients across the valved stent increased (P ≤ 0.014) but remained within a physiological range in both groups (AP: 1.2 ± 0.6 mmHg, SA: 2.6 ± 2.0 mmHg). The longitudinal heart function remained within a physiological normal range (AP: 0.95 ± 0.1 cm, SA: 0.95 ± 0.1 cm) but was reduced in group SA. The ejection fraction decreased after stent implantation (AP: 52 ± 10%, SA: 48 ± 4%). The mean survival time was higher in group AP compared with group SA. CONCLUSIONS: The proof-of-principle for the subannular fixation was shown with haemodynamic stability, low gradients and physiological longitudinal function. A decreased ejection fraction, survival time and fractures identify potential areas for improvement. With regard to the long-term outcome, the group with subannular fixation did not reach the results of the group with apical fixation in this study.

Transcatheter mitral valve implantation: a percutaneous transapical system.

Objectives: Despite recent achievements, implantation of a transcatheter mitral valved stent remains challenging. In this study, we present a different approach for implantation of a percutaneous mitral valved stent. Methods: Percutaneous transapical access is combined with, respectively, a left-transatrial, right-transatrial/transseptal or transfemoral/transseptal approach for mitral valve stent implantation and secure fixation. The apical fixation and occlusion are ensured with an Amplatzer occluder. This novel approach was tested in 22 porcine hearts in an in vitro setting under the guidance of fluoroscopy ( n = 11) and endoscopy ( n = 11). The in vitro setup included continuous flushing at 37 °C. We determined the feasibility, time of implantation, stent deployment and stent fixation. Results: Percutaneous mitral valved stent implantation was successful in all cases. Good handling properties and precise positioning were achieved. Time of implantation was comparable in the fluoroscopic and endoscopic groups at 10:41 ± 3:18 and 10:09 ± 2:42 min, respectively. Apical fixation with the occluder was excellent in all 22 cases. Conclusions: The feasibility of percutaneous mitral valved stent implantation has been demonstrated in preliminary in vitro experiments. Subsequent studies are warranted to determine the efficacy of this minimally invasive catheter-based mitral valved stent implantation.

Cytokine Reduction in the Setting of an ARDS-Associated Inflammatory Response with Multiple Organ Failure.

A 45-year-old male was admitted to our hospital with a small bowel obstruction due to torsion and was immediately scheduled for surgical intervention. At anesthesia induction, the patient aspirated and subsequently developed a severe SIRS with ARDS and multiple organ failure requiring the use of ECMO, CRRT, antibiotics, and low dose steroids. Due to a rapid deterioration in clinical status and a concurrent surge in inflammatory biomarkers, an extracorporeal cytokine adsorber (CytoSorb) was added to the CRRT blood circuit. The combined treatment resulted in a rapid and significant reduction in the levels of circulating inflammatory mediators. This decrease was paralleled by marked clinical stabilization of the patient including a significant improvement in hemodynamic stability and a reduced need for norepinephrine and improved respiratory function as measured by PaO2/FIO2, ventilator parameters, lung mechanics, and indirect measures of capillary leak syndrome. The patient could be discharged to a respiratory weaning unit where successful respiratory weaning could be achieved later on. We attribute the clinical improvement to the rapid control of the hyperinflammatory response and the reduction of inflammatory mediators using a combination of CytoSorb and these other therapies. CytoSorb treatment was safe and well tolerated, with no device-related adverse effects observed.

Is the Lecompte technique the last word on transposition of the great arteries repair for all patients? A magnetic resonance imaging study including a spiral technique two decades postoperatively.

OBJECTIVES: To compare the Lecompte technique and the spiral anastomosis (complete anatomic correction) two decades after arterial switch operation (ASO). METHODS: Nine patients after primary ASO with Lecompte and 6 selected patients after spiral anastomosis were evaluated 20.8 ± 2.1 years after ASO versus matched controls. Blood flow dynamics and flow profiles (e.g. vorticity, helicity) in the great arteries were quantified from time-resolved 3D magnetic resonance imaging (MRI) phase contrast flow measurements (4D flow MR) in addition to a comprehensive anatomical and functional cardiovascular MRI analysis. RESULTS: Compared with spiral reconstruction, patients with Lecompte showed more vortex formation, supranatural helical blood flow (relative helicity in aorta: 0.036 vs 0.089; P < 0.01), a reduced indexed cross-sectional area of the left pulmonary artery (155 vs 85 mm²/m²; P < 0.001) and more semilunar valve dysfunctions (n = 5 vs 1). There was no difference in elastic aortic wall properties, ventricular function, myocardial perfusion and myocardial fibrosis between the two groups. Cross-sectional area of the aortic sinus was larger in patients than in controls (669 vs 411 mm²/m²; P < 0.01). In the spiral group, the pulmonary root was rotated after ASO more towards the normal left position (P < 0.01). CONCLUSIONS: In this study, selected patients with spiral anastomoses showed, two decades after ASO, better physiologically adapted blood flow dynamics, and attained a closer to normal anatomical position of their great arteries, as well as less valve dysfunction. Considering the limitations related to the small number of patients and the novel MRI imaging techniques, these data may provoke reconsidering the optimal surgical approaches to transposition of the great arteries repair.

Cardiovascular interventional MR imaging: a new road for therapy and repair in the heart.

Over the last 5 years, interventional MR imaging has been fertile ground for research. Real-time MR imaging, combined with recent advances in other MR imaging modalities such as perfusion imaging and intravascular imaging, has opened up new paths for cardiac therapy. The recent reports on cardiac stem cell therapy guided and monitored by MR imaging suggest that we are already seeing the establishment of an important role for cardiac MR imaging in cardiac restoration. The collaborative effort from a multidisciplinary team of basic biologists, engineers, and clinicians will refine stem cell incubation and labeling for MR-guided transcatheter endomyocardial injections, and this in turn may facilitate new studies in humans. Several groups have demonstrated in animal studies the feasibility of MR-guided catheter interventions for the treatment of congenital heart disease and arrythmia therapy. Hence, applications in humans remain the challenge for the next years. Although there have been first reports of cardiac catheterizations in humans by combined use of x-ray fluoroscopy and MR imaging, there are no reports in the literature suggesting that active tracking methods by MR imaging have been applied to humans. Safety issues (namely, heating of catheters and wires) hamper clinical use, particularly in infants and children. Current reports are promising that these limitations will be overcome in the near future and will eventually reduce x-ray usage during catheterization. In its current state, cardiac MR imaging offers a unique opportunity to investigate new therapeutic strategies for the treatment of congenital and acquired heart disease.

Closing Yield Gaps: How Sustainable Can We Be?

Global food production needs to be increased by 60-110% between 2005 and 2050 to meet growing food and feed demand. Intensification and/or expansion of agriculture are the two main options available to meet the growing crop demands. Land conversion to expand cultivated land increases GHG emissions and impacts biodiversity and ecosystem services. Closing yield gaps to attain potential yields may be a viable option to increase the global crop production. Traditional methods of agricultural intensification often have negative externalities. Therefore, there is a need to explore location-specific methods of sustainable agricultural intensification. We identified regions where the achievement of potential crop calorie production on currently cultivated land will meet the present and future food demand based on scenario analyses considering population growth and changes in dietary habits. By closing yield gaps in the current irrigated and rain-fed cultivated land, about 24% and 80% more crop calories can respectively be produced compared to 2000. Most countries will reach food self-sufficiency or improve their current food self-sufficiency levels if potential crop production levels are achieved. As a novel approach, we defined specific input and agricultural management strategies required to achieve the potential production by overcoming biophysical and socioeconomic constraints causing yield gaps. The management strategies include: fertilizers, pesticides, advanced soil management, land improvement, management strategies coping with weather induced yield variability, and improving market accessibility. Finally, we estimated the required fertilizers (N, P2O5, and K2O) to attain the potential yields. Globally, N-fertilizer application needs to increase by 45-73%, P2O5-fertilizer by 22-46%, and K2O-fertilizer by 2-3 times compared to the year 2010 to attain potential crop production. The sustainability of such agricultural intensification largely depends on the way management strategies for closing yield gaps are chosen and implemented.

Frequent Dilatation of the Descending Aorta in Children With Hypoplastic Left Heart Syndrome Relates to Decreased Aortic Arch Elasticity.

BACKGROUND: Patients with hypoplastic left heart syndrome after a Norwood operation show dilatation and reduced distensibility of the reconstructed proximal aorta. Cardiac magnetic resonance imaging (CMR) and angiographic examinations indicate that the native descending aorta (DAo) is also dilated, but this has not been studied in detail. METHODS AND RESULTS: Seventy-nine children with hypoplastic left heart syndrome in Fontan circulation (aged 6.3±3.2 years) and 18 control participants (aged 6.8±2.4 years) underwent 3.0-tesla CMR. Gradient-echo cine and phase-contrast imaging was applied to measure cross-sectional areas (CSAs), distensibility, pulse wave velocity, and the incremental elastic modulus of the thoracic aorta. CSA of the DAo in patients was also compared with published percentiles for aortic CSA. Patients had significantly larger CSA of the DAo at the level of pulmonary artery bifurcation (229.1±97.2 versus 175.7±24.3 mm/m(2), P=0.04) and the diaphragm (196.2±66.0 versus 142.6±16.7 mm/m(2), P<0.01). In 41 patients (52%), CSA of the DAo was >95th percentile level for control participants, and the incremental elastic modulus of the aortic arch and the DAo was higher than in patients with normal CSAs (arch: 90.1±64.3 versus 45.6±38.9 m/s; DAo: 86.3±53.7 versus 47.1±47.6 m/s; P<0.01). Incremental elastic modulus of the aortic arch and the DAo correlated with the CSA of the DAo (arch: r=0.5; DAo: r=0.49; P<0.01). CONCLUSIONS: Children with hypoplastic left heart syndrome frequently show dilatation of their DAo associated with increased stiffness of the aortic arch. Higher aortic impedance increases the afterload of the systemic circulation and likely contributes to the burden of the systemic right ventricle.

Long term follow-up of left ventricular performance and size of the great arteries before and after one- and two-stage arterial switch operation of simple transposition.

OBJECTIVE: Long-term angiographic evaluation of left ventricular performance and size of the great arteries after one-stage neonatal versus two-stage arterial switch operation (ASO) of simple transposition. METHODS: Analysis of cineangiographic studies obtained during the process of two-stage ASO for 34 patients and after neonatal repair for 52 patients. RESULTS: At early follow-up after two-stage ASO the left ventricular enddiastolic volume (LVEDV) was +1.8 standard deviations (S.D.) larger than LVEDV of control patients, but normalized completely (0.0 S.D.) at late follow-up. In contrast, after neonatal repair the LVEDV was always normal, and the median EF was significantly higher than after two-stage ASO (73 vs. 68%). The diameters of the native pulmonary annulus and sinus increased significantly after pulmonary artery banding to +4.5 and +4.8 S.D., respectively. After ASO, a significant decrease of the respective sizes occurred from early to late follow-up (annulus: +6.0 to +2.1 S.D.; sinus: +7.1 to +4.1 S.D.). After neonatal ASO the neoaortic annulus and sinus were only +1.5 and +2.7 S.D. larger than the comparable normal structures. The differences to the two-stage group were significant. In both groups, the neoaortic anastomosis had no diameters significantly different from normal. After one- and two-stage repair, the size of the neopulmonary annulus and sinus decreased similarly in both groups from early to late follow-up (annulus +0.9 to -2.4 S.D.; +0.3 to -2.8 S.D.; sinus: -0.7 to -1.6 S.D.; -0.7 to -1.8 S.D.). CONCLUSIONS: Neonatal ASO has definite advantages over two-stage repair concerning LV-performance and the degree of dilation of the neoaortic root. The significantly reduced size of the neopulmonary root after both procedures is remarkable, but fortunately mostly without clinical significance.

Two-dimensional global longitudinal strain rate is a preload independent index of systemic right ventricular contractility in hypoplastic left heart syndrome patients after Fontan operation.

BACKGROUND: Assessment of systemic right ventricular (RV) function in patients with hypoplastic left heart syndrome is important during long-term follow-up after Fontan repair. Traditional echocardiographic parameters to evaluate systolic ventricular function are affected by loading conditions. The only generally accepted load-independent parameter of systolic function, end systolic elastance (Ees), requires invasive catheterization. Therefore, we sought to determine if parameters obtained by 2-dimensional speckle tracking (2DST) were affected by acute changes in preload and correlated with catheterization-derived indices of RV contractility in hypoplastic left heart syndrome patients after Fontan palliation. METHODS AND RESULTS: Fifty-two patients with hypoplastic left heart syndrome (median age, 6.6; range 2.9-22.2 years) were prospectively enrolled to have echocardiography and conductance catheter studies performed simultaneously. We compared traditional echo, 2-dimensional speckle tracking and catheterization-derived parameters during different states of preload at baseline and during dobutamine infusion. Global longitudinal strain (S) showed a tendency to decrease with preload reduction, whereas global longitudinal strain rate (SR) did not change (S: -17.7 ± 3.4% versus -16.9 ± 3.8%, P=0.08; SR: -1.30 ± 0.29 versus -1.34 ± 0.34 s(-1), P=0.3). S did not change with dobutamine infusion (-17.7 ± 3.4% versus -18.4 ± 3.9%, P=0.24), whereas SR increased significantly (-1.30 ± 0.29 versus -2.26 ± 0.49 s(-1), P<0.001). RV Ees correlated with SR (rs= -0.47, P<0.001), but not with S (rs=0.07, P=0.5) or other echocardiographic parameters. CONCLUSIONS: In contrast to S, SR was not affected by preload and correlated with Ees of the systemic RV. SR may be a useful noninvasive surrogate of RV contractility and suitable for follow-up of patients with hypoplastic left heart syndrome after Fontan palliation.