Forward Failure Research Articles

Mechanical Circulatory Support for Right Ventricular Primary Graft Dysfunction After Heart Transplant: A Review

ABSTRACTPrimary graft dysfunction (PGD) is the most common cause of early mortality following heart transplantation. Although PGD can affect both ventricles, isolated right ventricular dysfunction (RV‐PGD) is observed in nearly half of PGD patients. RV‐PGD requires specific medical management to support the preload, afterload, and function of the failing RV; however, the use of mechanical circulatory support of the RV (RV‐MCS) might be required when optimal medical therapy is insufficient in preventing forward failure and retrograde venous congestion. While RV‐MCS options provide the opportunity to prevent or to recover from circulatory shock states, MCS is associated with a significant risk of complications. As a result of recent developments in short‐term mechanical support devices, less invasive, percutaneous options for RV‐MCS are available. In this review, we discuss the available devices, their advantages and disadvantages, and reported outcomes in RV‐PGD.

미국 · 중국 · 한국 거시경제변수가 한국 주식수익률 및 변동성 지수 변화율에 미치는 영향 분석

Purpose - This article analyzes the impact of macroeconomic variables of the United States, China, and Korea on KOSPI and VKOSPI, in that United States and China have a great influence on Korea, having an export-driven economy. Design/methodology/approach - The influence of US, China, and Korea interest rates, industrial production index, consumer price index, US employment index, Chinese real estate index, and Korea's foreign exchange reserves on KOSPI and VKOSPI is analyzed on monthly basis from Jan 2012 to Aug 2023, using multifactor model. Findings - The KOSPI showed a positive relationship with the U.S. industrial production index and Korea's foreign exchange reserves, and a negative relationship with the U.S. employment index and Chinese real estate index. The VKOSPI showed a positive relationship with the Chinese consumer price index, and a negative relationship with the U.S. interest rates, and Korean foreign exchange reserves. Next, dividing the analysis into two periods with the Covid crisis and the analysis by country, the impact of US macroeconomic variables on KOSPI was greater than Chinese ones and the impact of Chinese macroeconomic variables on VKOSPI was greater than US ones. The result of the forward predictive failure test confirmed that it was appropriate to divide the period into two periods with economic event, the Covid Crisis. After the Covid crisis, the impact of macroeconomic variables on KOSPI and VKOSPI increased. This reflects the financial market co-movements due to governments' policy coordination and central bank liquidity supply to overcome the crisis in the pandemic situation. Research implications or Originality - This study is meaningful in that it analyzed the effects of macroeconomic variables on KOSPI and VKOSPI simultaneously. In addition, the leverage effect can also be confirmed through the relationship between macroeconomic variables and KOSPI and VKOSPI. This article examined the fundamental changes in the Korean and global financial markets following the shock of Corona by applying this research model before and after Covid crisis.

Excess renin is attributed to the combination of forward and backward failure in HFrEF.

Regulation of the renin-angiotensin system (RAS) in heart failure (HF) with reduced ejection fraction (HFrEF) still raises questions, as a large proportion of patients show normal renin levels despite manifest disease. Experimental venous congestion results in reduced renal perfusion pressure and stimulates renin secretion. We hypothesized that excess renin levels are mainly a result of right ventricular failure as a sequalae of left ventricular dysfunction. The study aimed to link right ventricular function (RVF) with renin levels and to investigate further contributors to excess RAS activation. Three hundred thirty-two chronic HFrEF patients undergoing routine ambulatory care were consecutively enrolled in a prospective, registry-based, observational study. Laboratory parameters, including cardiac-specific markers renin, aldosterone, and N-terminal pro-brain natriuretic peptide (NT-proBNP), echocardiographic examination (n=247), and right heart catheterization (n=85), were documented. The relationship between renin and its respective parameters was analysed. Renin concentration was not associated with the New York Heart Association class or NT-proBNP. Systolic blood pressure, systemic vascular resistance, serum sodium, aldosterone, and lactate dehydrogenase were associated with increased renin levels (P<0.035 for all). Renin levels similarly increased with worsening of RVF parameters such as fractional area change, tricuspid annular plane systolic excursion, tissue Doppler imaging, and inferior vena cava diameter (P<0.011 for all), but not with pulmonary pressure. Excess renin levels were observed when worsening RVF was combined with reduced renal perfusion {625μIU/mL [interquartile range (IQR): 182-1761] vs. 67μIU/mL [IQR: 16-231], P<0.001}, which was associated with worse survival. While unrelated to classical indices of HF severity, circulating renin levels increase with the worsening of RVF, especially in the combined presence of forward and backward failure. This might explain normal renin levels in HFrEF patients but also excess renin levels in poor haemodynamic conditions.

Design, construction and evaluation of a miniature soil bin plus predicting the measured parameters during primary tests using ANFIS

A clear understanding of soil-machine interaction is utilised in many areas, such as rational design and performance optimisation of soil-engaging tools/implements. This research developed a new soil bin to investigate the interaction between soil-narrow tines and soil failure. The new soil bin consisted of a chassis, a bin, a variable speed carriage and a bolt and nut type power transmission system between the motor and carriage. The design criteria of the new soil bin were based on the drive system's immediate acceleration of the carriage unit. A curved chisel tine was tested to evaluate the system's capabilities. Three parameters, including lift height, failure side area and forward failure distance, were investigated at two forward speeds of 0.037 and 0.05 m/s and three rake angles of 5°, 10° and 20°. An analysis of variance (ANOVA) test revealed the effect of rake angle on the lift height, failure side area, and forward failure distance was significant (P < 0.01). However, the forward speed did not have any significant influence on parameters. Also, the lift height and failure side area increased significantly (P < 0.01) by increasing the rake angle, while the forward failure distance decreased. Regarding soil failure, the results were in harmony with Godwin and Spoor's model. The regression and ANFIS models were developed to predict the output parameters by considering input parameters. The R2 values and ANFIS models were 0.4895, 0.7264, 0.9856, and 0.9999, 1, 1, respectively, for lift height, side area, and forward distance. Therefore, ANFIS approach was more accurate for predicting soil failure parameters.

By using the new hemodynamic definition of pulmonary hypertension in patients with left heart disease the prognostic value of different phenotypes might be lost

Abstract Background and aims In the 2022 ECS/ERS pulmonary hypertension (PH) guidelines the threshold for increased pulmonary vascular resistance (PVR) was lowered from 3 to 2 Wood Units (WU). Consequently, in patients with PH due to left heart disease, the proportions of patients with combined pre- and postcapillary PH (CpcPH) will increase while the proportion with isolated post-capillary PH (IpcPH) will decrease. In the present study we investigate in patients with left heart disease the impact of this revision in terms of hemodynamic profile, right ventricular (RV) function and prognostication. Methods. Two-hundred and two patients consecutively referred for heart transplant or heart failure work-up were included with right heart catheterization and echocardiography within 48 hours. RV dysfunction was graded using a novel echocardiographic score allocating one point each for (1) systolic pulmonary artery pressure (PAP) &amp;gt;40 mmHg, (2) reduced tricuspid annular plane systolic excursion (TAPSE&amp;lt;17 mm), (3) RV area dilatation, (4) moderate/severe tricuspid regurgitation and (5) reduced inferior cava collapsibility. For assessment of prognostication, we studied the end-point of all-cause mortality. Results. One-hundred and seventy-three patients (86%) had left ventricular ejection fraction &amp;lt;40%. Eighty-nine patients (44%) underwent heart transplantation and the median (25%; 75% percentile) follow-up time (years) was 1.8 (0.35; 6.7). Sixty patients (30%) had mean PAP&amp;lt;20 mmHg, thus no PH. Ninety-six patients (48%) had IpcPH using PVR 3 WU as threshold. Lowering the threshold to PVR 2 WU decreased the corresponding proportion to 24%. The degree of backward failure (PA wedge pressure), forward failure (cardiac index) or RV dysfunction (RVD score) did not significantly differ by the change in hemodynamic definition (Table). With the previous hemodynamic definition, the Kaplan-Meier curves demonstrated increased mortality in CpcPH patients compared with IpcPH (Figure B). Using the new definition this difference was not present (Figure B). Conclusions. The revised hemodynamic definition of PH significantly increases the proportion with CpcPH, but does not significantly alter the hemodynamic or RV function profiles in left heart disease patients with IpcPH or CpcPH phenotype. However, our findings indicate that by using the new hemodynamic definition of IpcPH and CpcPH phenotype the prognostic value of this hemodynamic classification might be lost.Table

Hepatorenal dysfunction in patients with chronic thromboembolic pulmonary hypertension.

Cardiac interactions with organs such as the liver or kidneys have been described in different cardiovascular diseases. However, the clinical relevance of hepatorenal dysfunction in chronic thromboembolic pulmonary hypertension (CTEPH) remains unclear. We determined the association of hepatorenal dysfunction (measured using the Model for End-stage Liver Disease Sodium [MELDNa] score) with right heart function and survival in patients with CTEPH. We analyzed all patients with CTEPH in the Giessen Pulmonary Hypertension Registry who had available MELDNa scores and were not taking vitamin K antagonists. The MELDNa score was calculated as MELD score - serum Na - (0.025 * MELD score * (140 - serum Na)) + 140; the MELD score was calculated as 10*(0.957*ln(creatinine)+0.378*ln(bilirubin)+1.12*ln(International Normalized Ratio))+6.43. Seventy-two patients were included (74% female; median [Q1, Q3] MELDNa: 9 [6, 11]). MELDNa correlated well with right atrial and ventricular function and pulmonary hemodynamics. Forward regression analysis revealed that hepatorenal dysfunction mainly depends on right atrial strain and tricuspid regurgitation, but not right ventricular systolic dysfunction. Hepatorenal dysfunction predicted mortality at baseline and follow-up (adjusted hazard ratios [95% confidence intervals] per unit increase of MELDNa: 1.6 [1.1, 2.4] and 1.8 [1.1, 2.9], respectively). Changes in hepatorenal function also predicted mortality. Hepatorenal dysfunction in CTEPH is primarily associated with venous congestion rather than cardiac forward failure. As a surrogate parameter for hepatorenal dysfunction, MELDNa is a simple method to identify at-risk patients at baseline and follow-up.

Acute heart failure and cardiogenic shock : An update

Acute heart failure is aclinical syndrome resulting from elevated intracardiac filling pressures and a systemic venous congestion. In general, patients can present acutely without a history of structural cardiac disease (de novo heart failure) or with acute worsening of apre-existing dysfunction of the right or left ventricle. The patient population is overall very inhomogeneous and as a result there is also a distinct heterogeneity with respect to the underlying cardiac pathology that leads to the acute presentation. Ultimately, ventricular dysfunction leads to increased preload and afterload resulting in decreased perfusion and retrograde congestion. The forward failure (hypoperfusion) and backwards failure (systemic congestion) can lead to impaired end organ function or even organ failure resulting in cardiogenic shock, in which sufficient organ and tissue perfusion is no longer possible. Consequently, therapeutic strategies currently focus on rectification of the underlying cardiac dysfunction, reduction of volume overload (decongestion) and hemodynamic stabilization with drugs supporting the circulation in the case of a hypoperfusion syndrome. Despite numerous new therapeutic strategies within the last two decades, the empirical data based on randomized trials is considerably less solid than in chronic heart failure, which is expressed in the almost unchanged 1‑year mortality of approximately 20-30%.

The Kidney in Heart Failure: The Role of Venous Congestion.

Heart failure can lead to renal impairment, an interaction now termed “cardiorenal syndrome.” The prevalent physiological explanation for the renal impairment that accompanies heart failure centers around the forward failure hypothesis, which emphasizes the role of left ventricular dysfunction in causing edema, and the backward failure hypothesis, which singles out venous congestion as the dominant mechanism of edema and reduced glomerular filtration rate. In this review, we provide an appraisal on venous congestion, an extremely important contributor that has received little attention. We also summarize the pharmacology of loop diuretics, explain current understanding of diuretic resistance, and address controversies regarding decongestive treatments.

High-power cold diodes for the protection of a 1.5 T superconducting MRI magnet system

Cold diodes play a crucial role in various operational aspects of the superconducting magnet of magnetic resonance imaging (MRI) scanners. The forward and reverse characteristics and failure modes are studied for two types of high-power rectifier diode to find their suitability for application at 4.2 K in a whole-body 1.5 T superconducting MRI magnet system. The diodes are characterized at various temperatures (300 K, 77 K and 4.2 K) in the current range up to 600 A. The turn-on voltage of the diodes at 4.2 K is found to be increased by 7–12 times that of room temperature. The diodes show negative differential resistance (NDR) beyond 1 A of forward current at 4.2 K. The forward voltage stabilizes in the range of 1.22–1.24 V after attaining the turn-on voltage in the range of 5–8 V. The significance of NDR is analysed for the MRI magnet. The long-term stability of the forward voltage is studied at 77 K with 550 A of forward current. Two modes of diode failure are also studied to foresee any failure during the operation of the magnet.

Analyzing the impact of guard-ring on different dual-direction SCR by device simulation and TLP measurement

In this paper, the impact of the traditional interdigital DDSCR structure (TI-DDSCR) and the embedded DDSCR (EM-DDSCR) structure with and without P+ guard-ring is analyzed under the 0.5-μm complementary and double-diffused MOSFET (CDMOS) technology. In order to verify and predict the characteristics of those electrostatic discharge (ESD) protection devices, a transmission line pulse (TLP) testing system and device simulation platform have been used in this work. The test results show that the introduction of P + guard ring will increase the device forward trigger voltage (Vt1) by about 3 V and forward holding voltage (Vh) by 4-6 V, but has little effect on the forward failure current (It2). The reverse Vh is reduced by 4–6 V, while the reverse It2 depends on the layout geometry. Due to the different layout geometry, on the TI-DDSCR structure with P+ guard ring, their reverse It2 is reduced from 13.07A to 8.05A. On the contrary, on the EM-DDSCR with P+ guard ring, their reverse It2 increased from 6.55A to 10.10A.

Unilateral Lung Congestion During Exercise in a Patient With a Single Pulmonary Vein Stenosis

A 55-year-old man underwent exercise stress echocardiography for evaluation of left inferior pulmonary vein stenosis. During exercise, ultrasound B-lines developed in the left lung only. Unilateral pulmonary congestion did not lead to forward or backward failure. The patient was followed up conservatively. (Level of Difficulty: Beginner.)

Left heart Impella-device to bridge acute mitral regurgitation to MitraClip-procedure: a novel implementation of percutaneous mechanical circulatory support

Abstract Background Acute mitral regurgitation (MR) is an emergency, often requiring urgent surgery. Severe acute MR presenting with hemodynamic collapse is usually caused by papillary muscle rupture or dysfunction after acute myocardial infarction (AMI) or chordal rupture, resulting in flail mitral leaflet(s). Preoperative stabilization is complex due to concomitant hemodynamic collapse and hypoxic respiratory failure. Finding the right balance between both preload and inotropic support is challenging. When patients are too sick for immediate surgical intervention, mechanical circulatory support can be considered because of its ability to both unload and reduce of cardiac work while increasing coronary perfusion and cardiac output. Nevertheless, even after initial stabilization, surgical risk remains high in critically ill acute severe MR patients and transcatheter treatments such as MitraClip are increasingly being explored. Methods Between August 2017 and September 2019, patients presenting with acute severe mitral regurgitation and considered too ill for immediate surgical intervention (EURO-II score &amp;gt;11.2% plus pulmonary oedema necessitating mechanical ventilation and/or hemodynamic instability), were selected for an Impella-assisted LV unloading technique as bridge to MitraClip-procedure. Five patients were selected for the combined left Impella/MitraClip-procedure in two tertiary cardiac ICUs. Results The mean age was 72 years. The cause of MR was ischemic in 20% and all patients presented in cardiogenic shock state, necessitating mechanical ventilation. The overall cardiac operative risk assessment (Euro-II) score predicted a 35% chance of in-hospital mortality. Cardiac output was severely impaired (mean LVOT VTI 8.2 cm). All patients were on inotropic support and supported by an Impella-CP pVAD (mean flow 2.5 Liter per minute; mean 6.3 days of support). In all cases, we managed to reduce the LVEDP below 15 mmHg using the combination of medical therapy (afterload reduction, inotropes), mechanical ventilation and pVAD-therapy. The MR was significantly reduced by a MitraClip-procedure in each Impella supported patient. The overall survival at discharge was 80%. One patient with late referral and multiple organ failure at presentation deceased due to refractory cardiogenic shock. Overall, severe MR was reduced to grade 1+ and all four patients survived 6 months after discharge with only one readmission for decompensated heart failure. Conclusions A combined strategy of Impella and MitraClip appears to be a novel, feasible alternative for patients presenting with acute, severe MR unable to proceed to a corrective surgical procedure at presentation due to severe left ventricular forward flow failure. In these cases, the early initiation of pVAD-support may reduce the risk of development of irreversible end- organ damage and dysfunction. Exploration in a larger, randomised population is warranted to investigate this strategy further. Funding Acknowledgement Type of funding source: None

Fault-Tolerant Control on a UH-60 Black Hawk helicopter using horizontal stabilator

The present study proposes an augmentation to the existing control mixing on the UH-60 Black Hawk to utilize the horizontal stabilator as a control effector in the feedback control to compensate for locked-in-place failure in the main-rotor swashplate actuators. Stabilator use has previously been shown to work in an adaptive sense, where the control mixing is remapped in flight once failure is detected. Now it is shown to perform well when the defined mixing utilizes the stabilator even on the undamaged aircraft, removing the need to detect and identify specific failures on the aircraft. Post-failure, the aircraft retains level 1 handling qualities ratings in pitch bandwidth and disturbance rejection. For forward actuator failure, the aircraft departs level 1 in the vertical rate response and pitch stability margin. There is a general improvement in handling qualities ratings as stabilator authority is increased. The aircraft is simulated flying a trajectory to a recoverable state post-failure, where the descent rate and forward speed are appropriate for a rolling landing. Stabilator hardover is also considered; the aircraft is shown to compensate for a stabilator hardover at a moderate flight speed, retaining level 1 handling qualities with only minor degradation relative to the undamaged aircraft except for failure at 80 knots showing level 3 stability margins.

Physics of building vulnerability to debris flows, floods and earth flows

Mass flows such as landslides and floods pose great risks to the built environment. In the literature the assessment of the building vulnerability to these different mass flows is evaluated separately and little effort has been made to investigate the interaction mechanisms between mass flows and buildings, leading to a lack of explicit failure mechanisms in many vulnerability models. In this study, the failure modes of a typical reinforced concrete building upon impact by debris flows, debris floods, floods and earth flows are discovered through an explicit finite element platform LS-DYNA. Five impact cases with increasing solid concentration; namely, low-intensity water flow, high-intensity water flow, debris flood, debris flow and earth flow, are considered. The intrinsic physics of building damage by these flow-like mass movements is compared. The frontal walls and side walls are vulnerable to any type of flow. A forward pushover failure mode, which is a global failure of the building frame, is observed in the high-intensity water flow and debris flood cases. Upon impact by an earth flow, progressive local failure of the columns at the ground floor can occur and lead to backward collapse of the building. Upon impact by a debris flow, both the local column failure and the global pushover collapse of building can occur, as debris flows with high solid contents are an intermediate flow sharing characteristics of both floods and earth flows. The in-depth study of the physics of building damage provides a solid basis to develop generic vulnerability models for such flow-like mass movements of varying solid contents.

P1361 Loading conditions might mimic right ventricular longitudinal dysfunction in patients with chronic left heart disease and forward failure

Abstract Background and aim Right ventricular failure (RVF) in patients with chronic left heart disease (LHD) has important prognostic implications. RV longitudinal function parameters (tricuspid annular plane systolic excursion, TAPSE; peak systolic longitudinal strain, RV-Str; tricuspid annulus systolic velocity, TAPSm) are today commonly used to define RV dysfunction. In the present study we hypothesized that longitudinal RV dysfunction (LDF) might be due to loading conditions and not necessarily RV dysfunction. Methods We retrospectively included 66 patients with LHD (age 52 ± 13 years, males 79%) that underwent right heart catheterization (RHC), ergospirometry (n = 47) and echocardiography (Echo) within 48 hours. Patients were divided into three groups from Echo data: normal RV function (TAPSE ≥17 mm + normal central venous pressure (CVP) from collapsibility of cava inferior, n = 18); LDF (TAPSE &amp;lt; 17 mm + normal CVP, n = 22) and RVF (CVP≥10 mmHg, n = 26). Results Patients with RVF had compared with normal and LDF lower peak VO2, more advanced LHD, enlarged RV and higher RV afterload (Table). Patients with LDF had compared with normal reduced stroke volume index (SVI). The patients with normal and LDF did not differ regarding right atrial pressure (RAP) response during exercise (P = 0.84). The longitudinal parameters did not differ between patients with LDF and RVF. Conclusions Longitudinal parameters in patients with chronic LHD and normal CVP should be interpreted with caution. Loading conditions with reduced stroke volume might mimic LDF. Normal (n = 18) LDF (n = 22) RVF (n = 26) Overall P-value Normal vs LDF Normal vs RVF LDF vs RVF Peak VO2 (mlO2/min/m2) 14.8 ± 3.3 13.5 ± 3 11 ± 2 0.001 0.29 &amp;lt;0.001 0.005 RAP (mmHg) 4 ± 3 4 ± 4 12 ± 3 &amp;lt;0.001 0.55 &amp;lt;0.001 &amp;lt;0.001 PASP (mmHg) 32 ± 13 37 ± 14 47 ± 11 &amp;lt;0.001 0.28 &amp;lt;0.001 0.002 PCWP (mmHg) 10 ± 6 14 ± 7 22 ± 5 &amp;lt;0.001 0.03 &amp;lt;0.001 &amp;lt;0.001 SVI(ml/m2) 43 ± 10 34 ± 6 30 ± 9 &amp;lt;0.001 &amp;lt;0.001 &amp;lt;0.001 0.15 PVR (Wood unit) 2.0 ± 1.1 2.0 ± 0.8 2.3 ± 1.1 0.29 - - - RVdA (cm2) 19 ± 3 22 ± 7 26 ± 7 0.003 0.16 &amp;lt;0.001 0.04 RVsax (mm) 23 ± 4 25 ± 8 34 ± 8 &amp;lt;0.001 0.42 &amp;lt;0.001 &amp;lt;0.001 TAPSE (mm) 21 ± 4 12 ± 3 12 ± 3 &amp;lt;0.001 &amp;lt;0.001 &amp;lt;0.001 0.98 TAPSm (cm/s) 11 ± 3 8 ± 2 8 ± 2 &amp;lt;0.001 &amp;lt;0.001 &amp;lt;0.001 0.55 RV-Str (%) -24 ± 5 -16 ± 5 -15 ± 5 &amp;lt;0.001 &amp;lt;0.001 &amp;lt;0.001 0.87 PASP, pulmonary systolic pressure; PCWP, pulmonary capillary wedge pressure; PVR, pulmonary vascular resistance; RVdA, RV diastolic area; RVsax, RV short axis diameter.

P899 Reduced right ventricular longitudinal function in patients with chronic left ventricular disease can be due to left ventricular forward failure and not right ventricular dysfunction

Abstract Background and aim The occurrence of right ventricular failure (RVF) in patients with chronic left heart disease (LHD) has important therapeutic and prognostic consequences. Echocardiography (Echo) parameters describing the RV longitudinal function (tricuspid annular plane systolic excursion, TAPSE; peak systolic free wall longitudinal strain, RV-Str; tricuspid annulus peak systolic velocity, TAPSm) are today commonly used to define RV dysfunction. In the present study we hypothesised that these parameters are load dependent. Methods We retrospectively included 66 patients with LHD (age 52 ± 13 years, males 79%) that underwent right heart catheterization (RHC) and Echo within 48 hours. RHC was performed as part of diagnostic- or pre-transplant work-up. Fifty-six patients (85%) had left ventricular ejection fraction &amp;lt; 40%. From RHC data the patients were divided into three groups: Patients with RV decompensation and increased right atrial pressure (RAP) ≥10 mmHg (iRAP, n = 21), with normal RAP but reduced stroke volume index (SVI &amp;lt; 35 mL/m2) (rSVI, n = 21) and with normal RAP and normal SVI (nSVI, n = 24). Results Patients with iRAP had compared with rSVI/nSVI more advanced LHD with higher PAMP, PCWP and larger RV diastolic area (RVdA). TAPSE, RV-Str and FAC did not differ between iRAP and rSVI patients. The ratio RVdA/RV-Str was significantly higher in iRAP patients compared with rSVI and nSVI. The rSVI and nSVI patients did not differ regarding RAP response during supine exercise (P = 0.84). Conclusions Reduced RV longitudinal function in patients with chronic LHD and normal RAP can be due to left ventricular forward failure and not RV systolic dysfunction. iRAP (n = 21) rSVI (n = 21) nSVI (n = 24) Overall P-value iRAP vs rSVI iRAP vs nSVI rSVI vs nSVI RAP (mmHg) 13 ± 2 5 ± 3 4 ± 2 &amp;lt;0.001 &amp;lt;0.001 &amp;lt;0.001 0.34 PAMP (mmHg) 33 ± 8 24 ± 8 22±] &amp;lt;0.001 0.001 &amp;lt;0.001 0.34 PCWP (mmHg) 22 ± 5 16 ± 8 11 ± 6 &amp;lt;0.001 0.003 &amp;lt;0.001 0.025 CI (l/min/m2) 2.2 ± 0.4 2.2 ± 0.4 2.8 ± 0.5 &amp;lt;0.001 0.75 &amp;lt;0.001 &amp;lt;0.001 PVR (Wood unit) 2.6 ± 1.2 1.5 ± 1.6 1.9 ± 1.0 0.032 0.022 0.035 0.60 RVdA (cm2) 26 ± 7 21 ± 7 21 ± 5 0.012 0.007 0.017 0.63 TAPSE (mm) 12 ± 3 13 ± 3 18 ± 6 &amp;lt;0.001 0.28 &amp;lt;0.001 0.001 TAPSm (cm/s) 8 ± 2 8 ± 2 10 ± 4 0.06 - - - RV-str (%) -15 ± 5 -17 ± 5 -21 ± 6 0.002 0.11 0.001 0.028 FAC (%) 28 ± 9 29 ± 11 39 ± 11 &amp;lt;0.001 0.72 0.001 0.003 RVdA/RV-str (cm2/%) 2.2 ± 1.3 1.3 ± 0.7 1.1 ± 0.6 &amp;lt;0.001 0.013 0.001 0.27

Decongestive diuresis using combination intravenous loop diuretics plus chlorothiazide in type 1 acute cardiorenal syndrome and worsening acute kidney injury; a neglected paradigm in resource-poor settings

Over the last decade or more, there has grown a body of evidence demonstrating that renal dysfunction in heart failure is a combination of forward failure from reduced cardiac output and therefore reduced glomerular filtration rate, as well as "congestive renal failure" secondary to renal venous hypertension. We had demonstrated the efficacy of combination intravenous loop diuretics used concurrently with intravenous chlorothiazide to achieve significant renal salvage in such patients at the Mayo Clinic Health System in Northwestern Wisconsin. We describe a similar recent experience with three consecutive elderly patients at the University of Vermont Medical Center, Burlington, VT, USA. We posit that this paradigm of care is underutilized. We argue that aggressive decongestive therapy with combination intravenous loop and thiazide diuretics is a neglected and underutilized mechanism and must be utilized more frequently in the treatment of worsening renal failure with type 1 cardiorenal syndrome. This imperative is even most compelling in resource-poor settings where mechanical ultrafiltration with dialysis or similar machines is not available or simply not affordable. Moreover, we had also demonstrated that accelerated rising Pro B natriuretic peptide (Pro-BNP) in such patients portends a good prognosticator for renal salvage. We present here three consecutive elderly patients recently so managed successfully at the University of Vermont Medical Center in Burlington, VT, USA.

Phenotyping progression of secondary mitral regurgitation in chronic systolic heart failure.

BackgroundSecondary mitral regurgitation (sMR) drives adverse cardiac remodelling in patients with heart failure with reduced ejection fraction (HFrEF). Progression in severity over time contributes to a transition towards more advanced HF stages. Early identification of patients at risk for sMR progression remains challenging. We therefore sought to assess a broad spectrum of neurohumoral biomarkers in patients with HFrEF to explore their ability to predict progression of sMR.MethodsA total of 249 HFrEF patients were enrolled. Biomarkers encompassing key neurohumoral pathways in heart failure were sampled at baseline, and sMR progression was assessed over 3 years of follow‐up.ResultsOf 191 patients with nonsevere sMR at baseline, 18% showed progressive sMR within three years after study enrolment. Progression of sMR was associated with higher levels of MR‐proADM (adj.OR 2.25, 95% CI 1.29‐3.93; P = .004), MR‐proANP (adj.OR 1.84, 95% CI 1.14‐3.00; P = .012), copeptin (adj.OR 1.66, 95% CI 1.04‐2.67; P = .035) and CT‐pro‐ET1 (adj.OR 1.68, 95% CI 1.06‐2.68; P = .027) but not with NT‐proBNP (P = .54).ConclusionIncreased plasma levels of neurohumoral cardiac biomarkers are predictors of sMR progression in patients with HFrEF and add easily available incremental prognostic information for risk stratification. Importantly, NT‐proBNP was not useful to predict progressive sMR in the present analysis. On the contrary, MR‐proANP, primarily produced in the atria, copeptin partly triggered by intra‐cardiac and intra‐arterial pressures and MR‐proADM, a marker of forward failure and peripheral released vasoactive CT‐proET1, increase based on a progressive loading burden by sMR and may thus serve as better predictors of sMR progression.

COPD and heart failure: differential diagnosis and comorbidity.

Heart failure (HF) and chronic obstructive pulmonary disease (COPD) represent the most important differential diagnoses of dyspnea in elderly people. Heart failure is the inability of the heart to pump sufficient amounts of blood through the cardiovascular system. Pump failure is caused by compromised contractility and/or filling of the ventricles leading to forward and backward failure and subsequently to dyspnea. In COPD, the destruction and remodeling processes of the bronchiolar architecture inhibit proper exhalation of air, thereby leading to exhaustion of the thoracic muscles, insufficient oxygen diffusion, and dyspnea. Despite these fundamental differences in the pathophysiology of both disorders, their clinical presentation may be very similar. This renders accurate and timely diagnosis and therapy, especially in patients with coexisting disease, difficult. This clinical review summarizes typical problems in the diagnosis of COPD, HF, and coincident disease, and describes strategies that help avoid misdiagnosis and ineffective treatment.

Discrete element modeling of cultivator sweep-to-soil interaction: Worn and hardened edges effects on soil-tool forces and soil flow

Simulation of tool-to-soil interaction provides opportunities to accelerate new equipment design and evaluate performance of tillage tools. Simulation based evaluation of worn tillage tools performance on soil flow has not been done. Discrete Element Modelling (DEM) has a potential to simulate worn tool to soil interaction problems, where worn tools CAD can be generated using 3D scanning. The DEM parameters of Hertz-Mindlin with Parallel Bond model were calibrated to match draft force and soil failure zone measured from a tool bar moving at 0.22 m/s and 38 mm cutting depth. The draft force and soil forward failure zone were predicted at 7% and 24% relative errors compared to measured values, respectively. Using the optimized DEM soil model, the interaction of three 3D reconstructed sweeps (new sweep, carbide treated-worn, untreated-worn) with soil were simulated to compare their geometric wear dimensional loss, performance on soil forces and soil flow. Results showed that the carbide treated-worn sweep had similar soil draft force and soil forward failure distance as the new sweep. The untreated-worn sweep showed lower vertical force (less suction) and its wing induced soil failure zone (front and lateral) showed poor soil tilth quality compared with the carbide treated-worn sweep and the new sweep.