Left Loop Research Articles

Value of territorial work efficiency estimation in non-ST-segment-elevation acute coronary syndrome: a study with non-invasive left ventricular pressure-strain loops.

Non-ST-segment-elevation acute coronary syndrome (NSTE-ACS) patients with normal left ventricular (LV) ejection fraction (LVEF) and wall motion require a non-invasive tool to detect LV risk areas. This study utilized non-invasive LV pressure-strain loops to evaluate territorial myocardial work efficiency (WE) for identifying obstructive coronary artery stenosis, in patients with non-obstructive or obstructive coronary artery stenosis NSTE-ACS, the latter with or without occlusion. Global and territorial longitudinal strain (LS) analyses were performed via speckle-tracking imaging before coronary angiography. LV pressure-strain loops estimated global and territorial myocardial work index (MWI), constructive work (CW), wasted work (WW), and WE. Receiver operating characteristic curve analysis was used to determine the optimal cutoff value of independent parameters to detect obstructive coronary artery stenosis. Compared with non-obstructive, obstructive coronary artery stenosis showed significantly lower global and territorial LS, MWI, CW, and WE, and higher WW. Territorial LS, MWI, CW, and WE were significantly worse in territories of coronary occlusion. Territorial WE was the best parameter for predicting obstructive coronary artery stenosis (AUC 0.80, cutoff < 96%, sensitivity 73%, specificity 70%, P < 0.001). In patients with NSTE-ACS with normal wall motion and LVEF, territorial WE is more accurate than territorial LS or MWI to identify LV risk areas.

Effect ofLeft and Right Coronary Flow Waveforms on Aortic Sinus Hemodynamics and Leaflet Shear Stress: Correlation with Calcification Locations.

Coronary flow induces hemodynamic alterations in the aortic sinus region. The objectives of this study are to: (1) investigate the differences among sinus hemodynamics and leaflet wall shear stresses engendered by the left versus right versus non-coronary flow and (2) correlate respective wall shear stresses with leaflet calcification in patients. A left heart simulator flow loop with a tunable coronary circuit provided physiological coronary flow waveforms corresponding to the left coronary cusp case (LCC), right coronary cusp case (RCC), and non-coronary cusp case (NCC). High spatio-temporal resolution particle image velocimetry was conducted to quantify leaflet wall shear stress and sinus vorticity fields and to measure aortic leaflet tip kinematics. Thirty-one patients with severe calcific aortic valve disease were segmented from CT data for the calcific volumes in their respective left, right, and non-coronary cusps. Leaflet tip position during systole shows the RCC has a wider leaflet opening compared to LCC and NCC. Velocity and vorticity fields combined with leaflet position data show that sinus vorticity is diminished (peak ~ 43 s-1) in the LCC while RCC and NCC maintain high vorticity (~ 1200 and ~ 950 s-1 respectively). WSS magnitudes greater than 0.3 Pa show 20 and 81% greater occurrences in the LCC and RCC respectively compared to NCC. Significant differences [X2(2,n = 31) = 7.31,p=0.0258] between the calcification levels in each cusp of the patient population. Coronary flow differences between LCC, RCC, and NCC show significant impact on leaflet kinematics and sinus flow hemodynamics. Clinical data correlations of the coronary flow cases indicate the left coronary cusp has a higher likelihood of calcification compared to the right.

Hemodynamics during transcatheter aortic valve implantation in patients with severe aortic stenosis measured by invasive pressure volume loop analysis

Abstract Introduction Transcatheter aortic valve implantation (TAVI) for a stenotic aortic valve reduces the ventricular to aortic gradient and is expected to improve diastolic and systolic left ventricular function over the long-term. However, information about the early hemodynamic changes are lacking. To address this open question, we performed invasive pressure volume loop analysis prior and immediately after TAVI. Methods Invasive left ventricular pressure volume loop analysis was performed in 8 patients with aortic stenosis (mean 81.3 years) prior and immediately after transfemoral TAVI (conductance catheter). Parameters for global hemodynamics, afterload, contractility and the interaction of the cardiovascular system were analyzed. Results After TAVI, left ventricular ejection fraction (53.9% vs. 44.8%, p=0.018) as well as parameters for myocardial contractility such as preload recruitable stroke work (68.5 vs. 44.8mmHg, p=0.012) and endsystolic elastance (3.55 vs. 2.17, p=0.036) declined significantly compared to baseline. As sign of impaired diastolic function, TAU, a preload-independent measure of isovolumic relaxation (37.3 vs. 41.8ms, p=0.018) and enddiastolic pressure (13.1 vs. 16.4mmHg, p=0.015) increased after valve implantation. Contrarily, decreased ventricular-arterial coupling indicated early improvements in global cardiovascular energy efficiency (1.40 vs. 0.97 p=0.036). Arterial elastance had a strong correlation with the number of conducted rapid ventricular pacings (Pearson correlation coefficient, 0.772, p=0.025). Conclusion Invasive left ventricular pressure volume loop analysis revealed impaired systolic and diastolic function in the early phase after TAVI in patients with severe aortic stenosis. Contrarily, decreased ventricular-arterial indicated early improvement of global cardiovascular energy efficiency. PV Loop pre and post TAVI Funding Acknowledgement Type of funding source: None

Non-invasive myocardial workiIndices derived from left ventricular pressure-strain loops in predicting the response to cardiac resynchronization therapy

Abstract Background Non-invasive left ventricular (LV) pressure-strain loops (PSLs) which generated by combining LV longitudinal strain with brachial artery blood pressure, provide a novel method of quantifying global and segmental myocardial work (MW) indices with potential advantages over conventional echocardiographic strain which is load-dependent. The method has been introduced in echocardiographic software recently, making MW calculations more effectively and rapidly. The aim was to evaluate the role of non-invasive MW indices derived from LV PSLs in the prediction of cardiac resynchronization therapy (CRT) response. Methods 106 heart failure (HF) patients scheduled for CRT were included for MW analysis. Global and segmental (septal and lateral at the mid-ventricular level) MW indices were accessed before CRT. Response to CRT was defined as ≥15% reduction in LV end-systolic volume at 6-month follow-up in comparison with baseline value. Results CRT response was observed in 78 (74%) patients. At baseline, global work index (GWI) and global constructive work (GCW) were significant higher in CRT responders than in non-responders (both P&amp;lt;0.05). Besides, responders exhibited a significantly higher Mid Lateral MW and Mid Lateral constructive work (CW) (both P&amp;lt;0.001) but a significantly lower Mid Septal MW and Mid Septal myocardial work efficiency (MWE), as well as a significantly higher Mid Septal wasted work (WW) than non-responders (all P&amp;lt;0.01). Baseline Mid Septal MWE (OR 0.975, 95% CI 0.959–0.990, P=0.002) and Mid Lateral MW (OR 1.003, 95% CI 1.002–1.004, P&amp;lt;0.001) were identified as independent predictors of CRT response in multivariate regression analysis. Mid Septal MWE ≤42% combined with Mid Lateral MW ≥740 mm Hg% predicted CRT response with the optimal sensitivity of 79% and specificity of 82% (AUC = 0.830, P&amp;lt;0.001). Conclusion Mid Septal MWE and Mid Lateral MW can successfully predict response to CRT, and their combination can further improve the prediction accuracy. Assessment of MW indices before CRT could identify the marked misbalance in LV myocardial work distribution and has the potential to be widely used as a reliable complementary tool for guiding patient selection in clinical practice. Funding Acknowledgement Type of funding source: None

A closer look at physiological indicators of cardiovascular function post‐transplantation

A closer look at physiological indicators of cardiovascular function post‐transplantation

Complete hemispherotomy leads to lateralized functional organization and lower level of consciousness in the isolated hemisphere.

ObjectiveTo quantify whole‐brain functional organization after complete hemispherotomy, characterizing unexplored plasticity pathways and the conscious level of the dissected hemispheres.MethodsEvaluation with multimodal magnetic resonance imaging in two pediatric patients undergoing right hemispherotomy including complete callosotomy with a perithalamic section. Regional cerebral blood flow and fMRI network connectivity assessed the functional integrity of both hemispheres after surgery. The level of consciousness was tested by means of a support vector machine classifier which compared the intrinsic organization of the dissected hemispheres with those of patients suffering from disorders of consciousness.ResultsAfter hemispherotomy, both patients showed typical daily functionality. We found no interhemispheric transfer of functional connectivity in either patient as predicted by the operation. The healthy left hemispheres displayed focal blood hyperperfusion in motor and limbic areas, with preserved network‐level organization. Unexpectedly, the disconnected right hemispheres showed sustained network organization despite low regional cerebral blood flow. Subcortically, functional connectivity was increased in the left thalamo‐cortical loop and between the cerebelli. One patient further showed unusual ipsilateral right cerebello‐cortical connectivity, which was explained by the mediation of the vascular system. The healthy left hemisphere had higher probability to be classified as in a minimally conscious state compared to the isolated right hemisphere.SignificanceComplete hemispherotomy leads to a lateralized whole‐brain organization, with the remaining hemisphere claiming most of the brain's energetic reserves supported by subcortical structures. Our results further underline the contribution of nonneuronal vascular signals on contralateral connectivity, shedding light on the nature of network organization in the isolated tissue. The disconnected hemisphere is characterized by a level of consciousness which is necessary but insufficient for conscious processing, paving the way for more specific inquiries about its role in awareness in the absence of behavioral output.

Left ventricle end-systolic elastance, arterial-effective elastance, and ventricle-arterial coupling in Epilepsy.

Sudden unexpected death in epilepsy (SUDEP) is a tragic event. Cardiac models of sudden death state that, paradoxically, healthy individuals compose most of the victims of this event. Exploration of cardiac physiological variables related to outcome could help unveil risk markers for sudden death in epilepsy. We investigated left ventricle end-systolic elastance, arterial-effective elastance and ventricle-arterial coupling (VAC) in PWE compared with controls. Adult patients with temporal lobe epilepsy without known cardiovascular diseases were submitted to treadmill test and transthoracic echocardiogram. Individuals without epilepsy matched by sex, age, and body mass index composed the control group. Cardiac risk factors, exercise performance, autonomic data from treadmill test, systolic and diastolic function, morphological cardiac data, and left ventricle pressure-volume loop were recorded. Sixty subjects were consecutively enrolled (30 PWE and 30 controls). Epilepsy duration was 22.5±10.7years (age of onset 15.2±10.1years). Treadmill variables were significantly worse in TLE patients compared with controls. End-systolic elastance, arterial-effective elastance, and ventricle-arterial coupling were similar between groups. Female sex, percentage of maximal predicted heart rate achieved in exercise, exercise time, and epilepsy duration explained 28,4% of VAC in PWE in multiple stepwise linear regression (P=.018). Some aspects of the cardiac pressure-volume curves, mainly linked to left ventricle systolic performance, contractile function and their interaction with afterload appears normal in young PWE and cannot explain their increase risk to adverse outcomes or lower physical fitness.

Quantification of left ventricular contribution to stroke work by longitudinal and radial force-length loops.

Left ventricular (LV) stroke work (SW) is calculated from the pressure-volume (PV) loop. PV loops do not contain information on longitudinal and radial pumping, leaving their contributions to SW unknown. A conceptual framework is proposed to derive the longitudinal and radial contributions to SW, using ventricular force-length loops reflecting longitudinal and radial pumping. The aim of this study was to develop and validate this framework experimentally and to explore these contributions in healthy controls and heart failure patients. Thirteen swine underwent cardiovascular magnetic resonance (CMR) and LV pressure catheterization at baseline (n = 7) or 1 wk after myocardial infarction (n = 6). CMR and noninvasive PV loop quantification were performed on 26 human controls and 14 patients. Longitudinal and radial forces were calculated as LV pressure multiplied by the myocardial surface areas in the respective directions. Length components were defined as the atrioventricular plane and epicardial displacements, respectively. Contributions to SW were calculated as the area within the respective force-length loop. Summation of longitudinal and radial SW had excellent agreement with PV loop-derived SW (ICC = 0.95, R = 0.96, bias ± SD = −4.5 ± 5.4%) in swine. Longitudinal and radial contributions to SW were ~50/50% in swine and human controls, and 44/56% in patients. Longitudinal pumping required less work than radial to deliver stroke volume in swine (6.8 ± 0.8 vs. 8.7 ± 1.2 mJ/mL, P = 0.0002) and in humans (11 ± 2.1 vs. 17 ± 4.7 mJ/mL, P < 0.0001). In conclusion, longitudinal and radial pumping contribute ~50/50% to SW in swine and human controls and 44/56% in heart failure patients. Longitudinal pumping is more energy efficient than radial pumping in delivering stroke volume.NEW & NOTEWORTHY A novel method for quantifying the contributions of longitudinal and radial pumping to stroke work using global left ventricular force-length loops was proposed and validated, which can be quantified noninvasively using cardiovascular magnetic resonance and brachial cuff pressure. We found that longitudinal and radial pumping contributes equally to stroke work in controls and 44/56% in heart failure patients, and that the longitudinal pumping is more energy efficient in delivering stroke volume than radial pumping.

Our arteriovenous fistula experiences with grafts in hemodialysis patients

Aim: In patients whose life is dependent on hemodialysis, the most suitable vascular access routes are arteriovenous fistulas made with native vessels. However, in patients whose natural vessels are depleted, or not suitable, arteriovenous fistulas can be opened with artificial grafts. Our aim is to examine arteriovenous fistulas opened with synthetic grafts in hemodialysis patients who do not have native vascular access in the upper extremity and share our results.Methods: Patients who underwent opening of an arteriovenous fistula with a synthetic graft to the upper extremities in Adıyaman University Faculty of Medicine, Cardiovascular Surgery Clinic between December 2012 and December 2018 were examined in this retrospective cohort study. They were screened for age, gender, end-stage renal failure etiology, complications in vascular access site, postoperative follow-up, and duration of use. Primary and secondary patency rates were determined.Results: It was determined that synthetic grafts were used in 33 (15 males, 18 females) out of 436 arteriovenous fistulas (AVF) opened to 372 patients. The mean age was 59.2 (17) years. Left radiocephalic (RC) straight graft fistula was opened in 2 patients, left brachiocephalic (BC) straight graft fistula was opened in 12, left BC distal loop AVF in 13, right BC distal loop AVF in 1, left brachioaxillary (BA) distal loop AVF in 3 and right BA distal loop was used to open an AVF in 2 patients. Primary cumulative patency rates were as follows: 72% in the 3rd month, 65% in the 6th month, 42.24% in the 12th month. The secondary patency rates were 33.9% in the 60th month, 12% in the 60th month, 96.96% in the 12th and 24th months, 90.28% in the 36th and 48th months, 59.12% in the 60th month and 43.11% in the 72nd month.Conclusion: In chronic renal failure patients who do not have a natural vascular access routes or whose natural routes have been exhausted, AVFs that are opened to the upper extremities with a synthetic graft are suitable vascular access routes for long-term dialysis.

Biventricular Assessment of Cardiac Function and Pressure-Volume Loops by Closed-Chest Catheterization in Mice.

Assessment of cardiac function is essential to conduct cardiovascular and pulmonary-vascular preclinical research. Pressure-volume loops (PV loops) generated by recording both pressure and volume during cardiac catheterization are vital when assessing both systolic and diastolic cardiac function. Left and right heart function are closely related, reflected in ventricular interdependence. Thus, recording biventricular function in the same animal is important to get a complete assessment of cardiac function. In this protocol, a closed chest approach to cardiac catheterization consistent with the way catheterization is performed in patients is adopted in mice. While challenging, the closed chest strategy is a more physiological approach, because opening the chest results in major changes in preload and afterload that create artifacts, most notably a fall in systemic blood pressure. While high-resolution echocardiography is used to assess rodents, cardiac catheterization is invaluable, particularly when assessing diastolic pressures in both ventricles. Described here is a procedure to perform invasive, closed chest, sequential left and right ventricular pressure-volume (PV) loops in the same animal. PV loops are acquired usingadmittance technology with a mouse pressure-volume catheter and pressure-volume system acquisition. The procedure is described, beginning with the neck dissection, which is required to access the right jugular vein and the right carotid artery, to the insertion and positioning of the catheter, and finally the data acquisition. Then, the criteria required to ensure the acquisition of high-quality PV loops are discussed. Finally, the analysis of the left and right ventricular PV loops and the different hemodynamic parameters available to quantify systolic and diastolic ventricular function are briefly described.

The first-countability of paratopological left-loops

In this paper, we introduce paratopogical left-loops, as natural generalizations of paratopogical left Bol loops defined by Z. Cai, S. Lin and W. He in [7], and prove that some known results for paratopological groups are still valid for paratopogical left-loops. The main results are: (i) every weakly first-countable paratopological left-loop is first-countable; (ii) a sequential, csf-countable, regular paratopological left-loop is first-countable if and only if it contains no closed copy of Sω.

P1510 Assessment of left ventricular relaxation time constant by noninvasive left ventricular pressure-strain loop: invasive validation

Abstract Introduction Left ventricular (LV) relaxation time constant, Tau (τ), is one of the best indexes to evaluate left ventricular diastolic function and is usually assessed invasively. Tau is the time constant of the exponential regression Pt =(P0-P∞)e-t/τ+P∞ that expresses left ventricular isovolumic pressure decay, where Pt is LV pressure (LVP) at time t, P0 is LVP at dP/dtmin and P∞ is the asymptotic pressure, to which relaxation would lead if completed without LV filling. Several noninvasive methods were developed to calculate Tau, however, they are time-consuming and complicated. Recently, a simple method regional left ventricular pressure–strain loops and myocardial work was introduced and validated. We hypothesize that left ventricular relaxation time constant can be derived and calculated from the LV pressure–strain loops. Objective To calculate noninvasively Tau using LV pressure–strain loops and compare it to invasive Tau assessment. Methods The study includes patients with preserved LV systolic function without significant valvular disease that were scheduled to elective coronary catheterization. During catheterization, a fluid-filled catheter was placed in the LV to measure pressure. Echocardiography was performed simultaneously with LV pressure recording. Three standard apical views were acquired and subsequently 2D strain analysis was performed using commercially available GE software and LV pressure–strain loops were calculated. Doppler signal was used for timing of valvular events. Tau was calculated by the equation τ =P/(-dP/dt) that is a derivative of the ventricular pressure decline P = P0e-t/τ+PB with respect to time. The pressure between peak negative dP/dt and the lowest LV pressure shortly after mitral valve opening was used for this calculation. The study was approved by the institutional ethics committee. Results Forty patients, (mean age 65.1 ± 10.9 years, 27 male, BSA1.93 ± 0.18 m2) were included in the study. Heart rate and the mean blood pressure at the time of catheterization were 69.9 ± 11.8 min-1 and 85.2 ± 18.8 mmHg, respectively. The mean LV end diastolic diameter was 44 ± 4 mm, the LV mass was 86.7 ± 25.2 g/m2, LVEF 58.4 ± 6.6% and GLS 21.0 ± 3.2%. Tau, calculated noninvasively using derivative method was significantly lower than invasively derived measurement (40.1 ± 13.4 vs 49.8 ± 7.7 msec, p = 0.002). However, a significant positive correlation was observed between the two methods (r =0.67, p &amp;lt;0.001, Figure). Conclusions This preliminary study demonstrates that Tau estimated by a noninvasive method using LV pressure–strain loops has a good correlation with Tau measured invasively. Therefore, Tau can be estimated noninvasively using novel left ventricular pressure–strain loop method. Abstract P1510 Figure.

A Simple and Effective Method to Treat Perigraft Seroma: A Case Report

Background: Perigraft seroma following creation of arteriovenous graft is uncommon but relatively difficult to solve. Progression of seroma not even will cause problem in graft puncture but sometimes will eventually result in failure of graft function or even infection. There are many different methods for the treatment of seroma, including serial aspiration, incision and drainage or graft replacement. Most of these methods are complicated and sometimes, the results are uncertain. Case report: We report a case of perigraft seroma found over left forearm arteriovenous loop graft. It has been observed for over one month and no resolution is noted. We used the outer fibrous pseudocapsule to wrap around the weeping graft to create a high pressure container to prevent further active transudation of serum-like fluid. Conclusions: This case show the feasibility of using pseudocapsule to fully cover the graft to prevent progression of seroma. The result is good and less recurrence rate is noted. This technique is considered a simple, effective solution to treat perigraft seroma and finally preserve the function of graft for dialysis.

Assessment of left ventricular myocardial work in Turner syndrome patients: insights from the novel non-invasive pressure-strain loop analysis method

Turner syndrome (TS), a relatively rare chromosomal disease, is associated with multiple cardiovascular risk factors that possibly lead to increased left ventricular afterload and functional impairment. The aim of this study was to investigate whether alterations in myocardial work and work efficiency can be found in TS patients through left ventricular pressure-strain loop analysis (PSL). Thirty-eight patients with TS and 19 healthy, age-matched controls were recruited for this study. Global peak systolic strain (GLPS) and PSL of the left ventricle was assessed in study participants. TS patients whose history included coarctation of the aorta or prior cardiac surgery were excluded from GLPS and PSL analyses (n=5). Median age was 16.00 years in the TS group and 16.35 years in the control group (P=0.236). GLPS did not show significant differences between both groups (P=0.524). TS patients demonstrated, compared to controls, a significantly higher global myocardial work index (BSA) (mean ± SD: 1,497±505 vs. 1,214±245 mmHg*%/m2; P=0.027). Heart rate was significantly increased in TS patients, compared to controls (mean ± SD: 90.08±14.79 vs. 73.95±15.05 bpm; P<0.001), and correlated significantly with global myocardial work index [body surface area (BSA)] within the TS cohort (r=0.558, P=0.001). TS patients showed signs of increased myocardial workload that were only detectable through the novel PSL analysis method and not through GLPS. Moreover, elevated resting heart rate was linked with increased myocardial workload in TS patients. Further studies will have to investigate whether TS patients may develop advanced left ventricular systolic dysfunction later in life.

Abstract 313: Inhibition of Resistin Protects against Heart Failure Injury by Targeting Gadd45α

Background: Resistin is an adipocyte-secreted hormone, increased Resistin levels are associated with the development of insulin resistance, diabetes, and cardiovascular disease. However, the role of Resistin in heart failure is still unclear. The aim of the present study is to investigate the molecular mechanisms underlying Resistin’s action in heart failure. Methods: C57BL/6 (WT) and Resistin knockout (RKO) mice were used. A mice transverse aortic constriction (TAC) induced heart failure model was established, and cardiac function and hemodynamic changes were measured by echocardiography and left ventricular pressure volume loops. A recombinant adeno-associated virus 9 (AAV9) vector was used to deliver resistin gene into the myocardium. RNA sequence was used to determine differentially expressed mRNA in heart from RKO and WT mice subjected to TAC or sham surgeries. Quantitative real-time PCR (qRT-PCR) and Western blot analyses were used to verify the expression levels of various fibrosis-related factors (collagen I, Fibronectin, and CTGF) and hypertrophy-related markers (ANF, β-MHC and Acta1). Results: Resistin inhibition attenuated while resistin overexpression (via AAV9-Resistin) exacerbated TAC-induced hypertrophy and cardiac dysfunction in WT and Resistin KO mice. Improvement in cardiac function was associated with decreased myocardial fibrosis as evidenced by histology and decreased mRNA levels of collagen I, fibronectin and CTGF in RKO-TAC hearts compared to WT or RKO-AAV9. In addition, myocardial tissue expression levels of ANF, β-MHC and Acta1 were also reduced in the RKO-TAC hearts. RNA sequencing analysis reveals that Gadd45a was significantly increased in RKO-TAC mice. The expression level of Gadd45a was verified by qRT-PCR and Western blot. Gadd45a expression was significantly downregulated in the RKO-TAC hearts following AAV9-Resistin delivery, suggesting that Resistin may control the regulation of Gadd45a. Conclusions: Resistin gene knockout increased Gadd45a expression in mouse model of heart failure, significantly reduced myocardial fibrosis and hypertrophy and improved heart function. The results of this study indicate that inhibition of resistin is a potential therapeutic method for treating heart failure.

Noninvasive Quantification of Pressure-Volume Loops From Brachial Pressure and Cardiovascular Magnetic Resonance.

Pressure-volume (PV) loops provide a wealth of information on cardiac function but are not readily available in clinical routine or in clinical trials. This study aimed to develop and validate a noninvasive method to compute individualized left ventricular PV loops. The proposed method is based on time-varying elastance, with experimentally optimized model parameters from a training set (n=5 pigs), yielding individualized PV loops. Model inputs are left ventricular volume curves from cardiovascular magnetic resonance imaging and brachial pressure. The method was experimentally validated in a separate set (n=9 pig experiments) using invasive pressure measurements and cardiovascular magnetic resonance images and subsequently applied to human healthy controls (n=13) and patients with heart failure (n=28). There was a moderate-to-excellent agreement between in vivo-measured and model-calculated stroke work (intraclass correlation coefficient, 0.93; bias, -0.02±0.03 J), mechanical potential energy (intraclass correlation coefficient, 0.57; bias, -0.04±0.03 J), and ventricular efficiency (intraclass correlation coefficient, 0.84; bias, 3.5±2.1%). The model yielded lower ventricular efficiency ( P<0.0001) and contractility ( P<0.0001) in patients with heart failure compared with controls, as well as a higher potential energy ( P<0.0001) and energy per ejected volume ( P<0.0001). Furthermore, the model produced realistic values of stroke work and physiologically representative PV loops. We have developed the first experimentally validated, noninvasive method to compute left ventricular PV loops and associated quantitative measures. The proposed method shows significant agreement with in vivo-derived measurements and could support clinical decision-making and provide surrogate end points in clinical heart failure trials.

Anorectal malformations: Early outcome analysis from a high-volume tertiary care institute

Context: Associated malformations in anorectal malformation (ARM) are of important implication with regard to final outcomes since the anorectal lesions that cause intestinal obstruction are correctable with operative intervention. Aims: To study the presentation, types of anomalies, associated malformations, and procedures performed in relation to the type of anomaly and early outcomes analysis of ARM patients in the neonatal period. Settings and Design: A retrospective study was performed from January 2016 to December 2016. Subjects and Methods: The study included all patients with ARM admitted in the Neonatal Intensive Care Unit. Results: There were 216 neonates having ARM with 173 males and 43 females (m:f = 4:1). High-type ARM was seen in 177 (81.94%) cases, while low type in 39 (18.06%) neonates. Associated malformations were documented in 67 (31.02%) neonates. Esophageal atresia (EA) was the most common (51) associated anomaly. Among the 200 procedures undertaken for ARM, left transverse loop colostomy was the most common (132). Only 83 (38.42%) neonates were diagnosed on the 1st day of life. There were 67 (31.02%) deaths, 145 (67.13%) survivors, and 4 (1.85%) cases left against medical advice. There were only 9 (17.65%) survivors among those associated with EA. Cardiovascular was the most common (39) cause of mortality followed by septicemia (30). Conclusions: An overall high mortality rate of 31.02% and an extremely high rate (74.51%) among those associated with EA were present. In spite of the progress made in the field of neonatal care, associated malformations compounded with a high volume of patients in our resource-limited institution negatively influence the outcome of ARM in the newborn period. Strict infection control measures for prevention of septicemia and investigations for other associated malformations are recommended to improve the outcomes.

Reducing Air Pollution - Towards making Indore a Smart, Clean, and Healthy City

Introduction: The Government of India initiated the Smart City Mission in 2015 with the aim of comprehensive urban development for 100 cities. Swachh Bharat Mission was also launched nationwide in 2014 with the goal of advancing universal sanitation coverage. Indore was selected as a Smart City; it was also declared the cleanest city in India in 2017 and in 2018 under Swachh Bharat. Indore is also participating in the United States Agency for International Development (USAID) - funded Building Healthy Cities Project, with the objective of improving the health of the city environment. As part of that objective, a closer examination of air pollution levels was conducted. Methodology: Annual average concentrations for sulphur dioxide, nitrogen oxides, and particulate matter (PM2.5 and PM10) from three air pollution measuring stations located in Indore’s Polo Ground (industrial), Kothari Market (commercial), and Kanodia Road, Vijay Nagar (residential) were analysed for trends during the last five years (2013-2017). For 2017, month-wise data were analysed for seasonal variations. Results: The annual average concentration of sulphur dioxide and nitrogen oxides did not change during the preceding five years. A declining trend was observed at all sites in concentration of PM10 from a range of 118-187 μg/m3 in 2013 to 77-81 μg/m3 in 2017. The PM2.5 concentration was measured only since 2016; 2017 levels were less when compared to the preceding year. Lower values were observed during the rainy season (July to September) for all pollutants. It was observed that, during the period, declining trend for PM10, various interventions were initiated in Indore, including night mechanical sweeping of city roads, free left loop roads to reduce traffic congestion, and an efficient systematic collection and disposal of solid waste. Conclusion: Declining trends of air pollution in particulate matter in Indore is evident, possibly due to various measures taken by the Municipal Corporation and Indore Smart City Mission. Further analysis is needed to understand how these trends can be sustained and how they may impact the respiratory health of Indore citizens.

Malcev algebras corresponding to smooth almost left automorphic Moufang loops

In this note, we introduce the concept of an almost left automorphic Moufang loop and study the properties of tangent algebras of smooth loops of this class.

4922Novel non-invasive left ventricular pressure-strain loop imaging demonstrates reduced myocardial work in cardiomyopathy with significant regional variation in non-ischemic cases

Background: Non-invasive left ventricular (LV) pressure-strain loop imaging is a novel method of calculating myocardial work (MW). The total area within the pressure-strain loop represents global MW (Figure1A). Myocardial shortening during systole and lengthening during isovolumic relaxation is classified as constructive work (CW) while myocardial lengthening during systole and shortening during isovolumic relaxation is classified as wasted work (WW). Purpose: Non-ischemic (CMPN-ISC) and ischemic cardiomyopathy (CMPISC) heart disease etiology influences management, prognosis as well as electromechanical correlates in heart failure. Differences in global MW and regional MW in patients with CMPN-ISC and CMPISC were assessed. Methods: Strain analysis was performed in 34 patients divided into: 1) Controls (n=10); 2) CMPN-ISC (n=10) (EF<40%; no evidence of significant coronary artery disease); 3) CMPISC (n=14) (EF<40%; coronary artery stenosis) immediately prior to coronary angiography. Dedicated MW software normalized standard LV pressure curves to brachial systolic cuff pressure and isovolumic and ejection duration. MW efficiency (GWE) was derived from the percentage ratio of: CW/(CW+WW). Segmental wasted work between septal and lateral segments were compared between CMPN-ISC and CMPISC. Results: Significantly higher global MW and GWE (p<0.05) was observed in controls. CMPISC demonstrated the lowest global MW (780mmHg%) but was not significantly different to CMPN-ISC (1054mmHg%). CMPN-ISC WW was significantly higher (p<0.05) compared to CMPISC (259 vs 185 mmHg%). Regional septal WW was significantly higher (p<0.05) in CMPN-ISC (459mmHg%) vs lateral WW (174mmHg%) (Figure1C). There was no significant difference between septal (198mmHg%) and lateral (161mmHg%) WW in CMPISC.