Elevated Cardiac Output Research Articles

Unmasking High-Output Heart Failure: Beyond Conventional Paradigms.

Heart failure (HF) poses a significant medical challenge, affecting millions of adults in the United States. High-output heart failure (HOHF) is a distinct subtype characterized by elevated cardiac output exceeding 8 L/min or a cardiac index >4 L/min/m². Patients with HOHF often present similarly to those with heart failure with reduced ejection fraction and heart failure with preserved ejection fraction. However, the underlying pathophysiology differs; triggered by a progressive decline in systemic vascular resistance, the ensuing elevation of cardiac output eventually leads to left ventricular remodeling and HF. Failure to differentiate HOHF from other variant forms of HF has implications for management, particularly relating to the use of vasodilator medications with potentially deleterious consequences, ensuing from the unrestrained adoption of societal guideline-directed medical therapy recommendations. Despite its clinical importance, HOHF remains under-examined in literature, with limited recognition and understanding among clinicians. This review aims to provide a comprehensive analysis of knowledge surrounding HOHF, exploring its definition, etiopathology, and underlying pathophysiological mechanisms. Recognizing the challenges in diagnosing HOHF, we propose a novel diagnostic algorithm tailored to address the subtleties of this often-misdiagnosed variant of HF.

Evaluation of Severe ultrasound and gene diagnosis in cardiac index and shock patient index of shock patients.

The kidney is the most vulnerable organ in severe patients. In severe cases, the fatality rate of acute kidney damage is as high as 30% ∼ 60%. Severe ultrasound is a non-invasive method to evaluate renal blood flow. It can give a semi-quantitative score of renal blood flow and measure the Resistance Index (RI), which can reflect renal artery blood flow to a certain extent. There is little literature on hemodynamic regulation in septic shock patients, but almost no research report on the relationship between hemodynamics and RI exists. Therefore, this paper proposed the analysis of severe ultrasound and gene diagnosis in cardiac index and peripheral vascular RI of shock patients. This paper mainly expounded on detecting renal function parameters and RI in patients with viral shock to understand further the correlation between them and renal flow and RI. It could be seen from the experimental results that the P values before and after resuscitation in the two groups with and without elevated Cardiac Output (CO) were 0.41 and 0.12, respectively, which were more significant than 0.05. RI had no apparent relationship with CO, and RI could not be used as an evaluation index for patients with early septic shock.

Ultrasonographic placental edematous changes as predictive markers of unplanned preterm birth in post-Fontan pregnancies: A single-center observational study.

Fontan surgery is a palliative procedure commonly performed for functional single-ventricle heart diseases. Fontan circulation is characterized by elevated central venous pressure and low cardiac output. It causes placental hypoxia, which could lead to poor obstetric outcomes. During post-Fontan pregnancies, ultrasonography may detect abnormal appearance of the placenta. We have focused on higher incidences of unexpected onset of labor when this ultrasonographic finding is present. In this study, we aimed to investigate whether this finding could be an indicator of premature delivery before pre-scheduled dates in post-Fontan pregnancies. During post-Fontan pregnancies, the placenta exhibits a mosaic pattern with areas of low and high echogenicity and unusually thick on ultrasonography. We refer to these changes as "ultrasonographic placental edematous changes." We retrospectively analyzed clinical charts and ultrasonograms for post-Fontan pregnancies between 2015 and 2022. Fifteen patients were included in this study. Ultrasonographic placental edematous changes in the placenta during pregnancy were detected in eight cases (53%). Six (75%) of these patients experienced unexpected premature labor. Two patients underwent vaginal delivery because of sudden onset of labor. Four patients underwent emergency cesarean sections. Two patients underwent planned preterm cesarean sections. In the seven pregnancies without placental edematous changes, all deliveries occurred on the pre-scheduled dates determined based on the maternal heart condition. Pregnancies with ultrasonographic placental edematous changes have a higher risk of unexpected preterm delivery than those without these changes. Ultrasonographic placental edematous changes may serve as predictive markers for unplanned preterm births in post-Fontan pregnancies.

Comparison of Hemodynamic Performance, Three-Dimensional Flow Fields, and Turbulence Levels for Three Different Heart Valves at Three Different Hemodynamic Conditions

The hemodynamic performance of different prosthetic heart valves is difficult to compare among studies due to a variety of test conditions and experimental techniques. Existing studies are typically limited to one family of valves (biological or mechanical) and testing conditions of 5l/min and often lack sufficient spatial resolution. To address these limitations, a pulse duplicator with a multi-view imaging system (Tomo-PIV) was employed to investigate the three-dimensional flow field in the aortic root of three different valves: a tri-leaflet mechanical heart valve (TRIFLO, Novostia), a bi-leaflet mechanical heart valve (On-X, Artivion), and a biological heart valve (Perimount, Edwards Lifesciences). The valves were tested at low (3 l/min), normal (5 l/min), and elevated (7 l/min) cardiac output (CO)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$(CO)$$\\end{document} under hypotensive (40/60mmHg), normotensive (80/120mmHg), and moderate hypertensive (105/170mmHg) pressure conditions, respectively. Compared to the Perimount, peak mean velocity was − 33%, − 24%, − 18% for the TRIFLO and − 32%, − 20%, − 11% for the On-X at low, moderate, and elevated CO\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$CO$$\\end{document}, respectively. Corresponding peak TKE\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$TKE$$\\end{document} values decreased by − 66%, − 57%, − 44% (TRIFLO) and − 60%, − 50%, − 36% (On-X). At low CO\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$CO$$\\end{document}, EOA\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$EOA$$\\end{document} was lower for Perimount (1.07cm2) than for TRIFLO (1.47cm2) and On-X (1.52cm2), while it increased for elevated CO\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$CO$$\\end{document} to 2.75cm2 (TRIFLO) and 2.16cm2 (Perimount and On-X). For all valves, increasing CO\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$CO$$\\end{document} led to increased flow velocities, higher EOA,\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$EOA,$$\\end{document} and higher levels of turbulence, and the spatial influence of the valve on the flow field in the ascending aorta was extended. TKE\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$TKE$$\\end{document} peaked closer to the STJ than for TRIFLO and Perimount.

Cardiovascular Adaptation in Fetal Growth Restriction: A Longitudinal Study From Fetuses at Term to the First Year of Life.

To investigate longitudinal trends in fetal and offspring cardiovascular adaptation in fetal growth restriction (FGR). Prospective longitudinal study. Fetal Medicine Unit. Thirty-five FGR pregnancies and 37 healthy controls assessed as term fetuses (mean age 37 ± 1 weeks) and again in infancy (mean age 8 ± 2 months). Conventional echocardiographic techniques, tissue Doppler imaging and speckle tracking echocardiography. Left ventricular (LV) and right ventricular (RV) geometry and function. Echocardiographic parameters were normalised by ventricular size adjusting for differences in body weight between groups. Compared to healthy controls, late FGR fetuses showed significant alterations in cardiac geometry with more globular LV chamber (LV sphericity index, 0.56 vs. 0.52), increase in biventricular global longitudinal systolic contractility (MAPSE, 0.29 vs. 0.25 mm; TAPSE, 0.42 vs. 0.37 mm) and elevated cardiac output (combined CO: 592 vs. 497 mL/min/kg, p < 0.01 for all). Indices of LV diastolic function in FGR fetuses were significantly impaired with myocardial diastolic velocities (LV A', 0.30 vs. 0.26 cm/s; IVS E', 0.19 vs. 0.16 cm/s) and LV torsion (1.2 vs. 3.5 deg./cm, p < 0.01 for all). At postnatal assessment, FGR offspring revealed persistently increased SAPSE (0.27 vs. 0.24 mm), LV longitudinal strain (-19.0 vs. -16.0%), reduced LV torsion (1.6 vs. 2.1 deg./cm) and elevated CO (791 vs. 574 mL/min/kg, p < 0.01 for all). Perinatal cardiac remodelling and myocardial dysfunction in late FGR fetuses is most likely due to chronic placental hypoxaemia. Persistent changes in cardiac geometry and function in FGR offspring may reflect fetal cardiovascular maladaptation that could predispose to long-term cardiovascular complications in later life.

Perinatal Cardiac Functional Adaptation in Hypoplastic Left Heart Syndrome: A Longitudinal Analysis

The perinatal transition is characterized by acute changes in cardiac loading. Compared with normal newborn combined cardiac output (CCO), single right ventricular (RV) output of neonates with hypoplastic left heart syndrome (HLHS) is markedly greater. The aim of this study was to examine the mechanisms of cardiac adaptation that facilitate this perinatal transition from late fetal to early neonatal life in HLHS. Prospectively recruited pregnancies complicated by fetal HLHS (n=35) and healthy control subjects (Ctrl; n=17) underwent serial echocardiography in late gestation (38±1weeks) and 6, 24, and 48hours after birth. Cardiac function was assessed using conventional, Doppler tissue, and speckle-tracking echocardiography. Term fetuses with HLHS had RV output comparable with Ctrl CCO via higher stroke volume. Compared with both left ventricular and RV indices of Ctrl, they exhibited globular and dilated right ventricles with reduced relative wall thickness (0.40±0.08 vs 0.49±0.10, P<.01), increased Tei index' (HLHS vs Ctrl left ventricle/Ctrl right ventricle: sphericity index, 0.9±0.25 vs 0.5±0.10/0.6±0.11; RV area index, 28±6 vs 15±3/17±5cm2/m2; Tei index', 0.65±0.11 vs 0.43±0.07/0.45±0.09; P<.0001 for all). Neonates with HLHS generated elevated RV cardiac output compared with Ctrl CCO via higher heart rate and stroke volume, with further RV dilatation, increased longitudinal systolic strain at 48hours (-17±4% vs -14±3%/14±5%) with reduced circumferential and rotational myocardial deformation and altered diastolic function. Neonates with HLHS also demonstrated right atrial enlargement with increased longitudinal strain: 6hours (33±12% vs 26±6%), 24hours (37±15% vs 26± 13%), and 48hours (38±11% vs 24±13%) (P<.0001). Term fetuses with HLHS exhibit altered RV geometry and RV systolic and diastolic functional parameters. After birth, further alterations in these cardiac parameters likely reflect adaptation to acutely altered RV loading from increasing cardiac output and pulmonary artery flow demands.

Ciliated Epibionts Modify the Cardiac Stress Reaction to Perceived Predation in Daphnia.

When animals perceive an acute stressor like a predator, they typically undergo a suite of physiological changes that function to improve survival during the encounter, such as elevation in cardiac output, to supply more energy to muscles. If bodily energy is limited, such as by parasites or infections, these functions could become less efficient and lessen host survival. In the aquatic world of microorganisms, individuals can become colonized by other organisms on their surface (epibionts), which could sap energy from their host from their weight, or even compete with the host for food. Here, we tested if one epibiont (a ciliated protozoan, Vorticella spp.) affects its hosts' ability to mount a physiological stress reaction. We collected wild daphnia (Daphnia ambigua) that had varying burdens of these on their bodies and exposed them to a simulated stressor (crushed daphnia, to simulate nearby predation) under a microscope while monitoring for changes in their heart rates in real time. Out of 121 daphnia, those with no Vorticella epibionts showed no meaningful changes in their heart rate after exposure, but those with light or heavy burdens showed immediate elevations (within 5 min). Moreover, the heart rates of heavily burdened daphnia continued to rise for 1.5 h thereafter, to as much as 17% higher than at baseline. These patterns were unexpected, as they suggest that the ciliated epibionts act to elevate their hosts' physiological reaction, rather than dampen it, perhaps by churning the water column around the host, thereby enhancing the chemical alarm cue. The procedures used in this study may be useful for future investigations into the acute stress reactions of daphnia or other microorganisms.

The Contemporary Role of Speckle Tracking Echocardiography in Cirrhotic Cardiomyopathy.

Cirrhotic cardiomyopathy (CCM) is characterized by elevated cardiac output at rest, an inability to further increase contractility under stress, and diastolic dysfunction. The diagnosis of CCM is crucial as it can lead to complications during liver transplantation. However, its recognition poses challenges with conventional echocardiography techniques. Speckle tracking echocardiography (STE), particularly global longitudinal strain (GLS), is a novel index that enhances the diagnostic efficacy of echocardiography for both ischemic and non-ischemic cardiomyopathies. GLS proves more sensitive in identifying early systolic dysfunction and is also influenced by advanced diastolic dysfunction. Consequently, there is an expanding scope for GLS utilization in cirrhotic cases, with newly updated diagnostic criteria for CCM incorporating GLS. Specifically, systolic dysfunction is now defined as either a left ventricular ejection fraction below 50% or an absolute GLS below 18%. However, conflicting data on GLS alterations in liver cirrhosis patients persist, as many individuals with advanced disease and a poor prognosis exhibit a hyperdynamic state with preserved or increased GLS. Consequently, the presence of CCM, according to the updated criteria, does not exhibit a significant association-in the majority of studies-with the severity of liver disease and prognosis. Furthermore, information on other indices measured with STE, such as left atrial and right ventricular strain, is promising but currently limited. This review aims to offer a critical assessment of the existing evidence concerning the application of STE in patients with liver cirrhosis.

Cardiohemodynamic responses and heart rate variability following an active orthostatic test among male residents of the North with different NOS3 (rs2070744) genotypes

AIM: This study explored associations between the -786TC (rs2070744) genetic polymorphism of the NOS3 gene and the main indices of systemic hemodynamics and heart rate variability following an active orthostatic test in men living in the North. MATERIAL AND METHODS: Eighty-three healthy men aged 33.5±1.5 yеаrs on average, who were permanent residents of the Magadan Region, comprised the sample. The participants underwent both resting and active orthostatic testing modes. Cardiovascular system variables were recorded using an automatic tonometer. Hemodynamic indices were then calculated. Short-term heart rate variability in frequency and spectral areas was simultaneously measured using the Varikard hardsoft complex unit. Genotyping was conducted using polymerase chain reaction. The sample was then divided into two groups: Group 1 consisted of homozygotes with the TT genotype (n=34), while Group 2 comprised carriers of the NOS3*C allele variant (genotypes TC+CC) associated with reduced nitric oxide production (n=49). RESULTS: By examining the complex vasomotor, chrono- and inotropic reactions of hemodynamic and heart rate variables during the active orthostatic test, we were able to discern unique patterns in the response of the two groups under study. Men in Group 1 demonstrated an elevated cardiac output response during orthostatic changes, while maintaining consistent vascular resistance values. This was accompanied by a shift towards sympathetic autonomic activity and an increase in the very low-frequency component of heart rate variability. In Group 2, individuals with sympathetic insufficiency and increased vascular resistance during the orthostatic test showed a 35% increase in the low-frequency component of the cardiac rhythm reflecting the importance of this indicator as a stimulator of blood pressure rhythm fluctuations mediated by baroreflex mechanisms. CONCLUSION: Our findings suggest that men lacking the NOS3*С allele variant in their genotype demonstrate more favorable responses to the active orthostatic test. This may reflect higher level of cardiovascular functional reserves. The 786TC (rs2070744) polymorphism of the NOS3 gene can be considered as a marker of cardiohemodynamic status and autonomic regulations during functional exercise, such as an active orthostatic test.

Abstract 16047: Quantifying the Cardiovascular Burden of Extreme Heat: A Meta-Analysis of Over 400 Laboratory-Based Heat Exposure Studies

Background: Heat waves are associated with increased fatalities from cardiovascular events, which has been attributed to increased cardiac strain secondary to the effects of heat on cardiac function. However, our understanding of these adjustments has come primarily from laboratory research employing insulated/encapsulated heating modalities (hot water perfusion suits). We evaluated whether the cardiac responses seen in this work reflect those experienced in studies exposing participants to high ambient temperatures. Methods: We systematically reviewed studies published up to January 2023 examining cardiac outcomes in adults rendered hyperthermic with water perfusion suits or unencapsulated exposure in a climate chamber. Mixed effects meta-analyses were conducted to evaluate whether changes in each outcome with increasing core temperature were modified by heating modality. We also estimated associations (natural spline) between ambient heat index and thermal and cardiac responses in the climate chamber studies. Results: 584 effect estimates of the heat-induced increase in heart rate (primary outcome) from 406 studies were included (~6800 participant exposures). Heart rate was 7 beats/min [95% CI: 3, 13] greater in the perfusion suit vs. climate chamber studies for similar increases in core temperature (P&lt;0.001). Likewise, there were greater elevations in cardiac output (slope difference: 1.2 L/min/°C [0.1, 2.3]), systolic pressure (14 mm Hg/°C [3, 24]), and rate pressure product (2923 mm Hg·beats/min/°C [1027, 4808]) with rises in core temperature in the perfusion suit compared to climate chambers studies (P≤0.036). In the climate chamber studies, core temperature and heart rate increased as much as 1.0°C [0.8, 1.3] and 31 beats/min [16, 37] (P&lt;0.001) in conditions reflective of deadly North American heat waves (heat index: 50-67°C). Conclusions: Our understanding of the effect of heat on cardiovascular responses primarily comes from encapsulated heating modalities, which we show overestimate heat-induced cardiac burden. To support public health research on extreme heat, we provide the first empirical estimates demonstrating considerable thermal and cardiac strain is experienced in conditions reflective of deadly heat waves.

Monoclonal antibodies neutralizing alpha-hemolysin, bicomponent leukocidins, and clumping factor A protected against Staphylococcus aureus-induced acute circulatory failure in a mechanically ventilated rabbit model of hyperdynamic septic shock.

Patients with septic shock caused by Staphylococcus aureus have mortality rates exceeding 50%, despite appropriate antibiotic therapy. Our objectives were to establish a rabbit model of S. aureus septic shock and to determine whether a novel immunotherapy can prevent or halt its natural disease progression. Anesthetized rabbits were ventilated with lung-protective low-tidal volume, instrumented for advanced hemodynamic monitoring, and characterized for longitudinal changes in acute myocardial dysfunction by echocardiography and sepsis-associated biomarkers after S. aureus intravenous challenge. To demonstrate the potential utility of this hyperdynamic septic shock model for preclinical drug development, rabbits were randomized for prophylaxis with anti-Hla/Luk/ClfA monoclonal antibody combination that neutralizes alpha-hemolysin (Hla), the bicomponent pore-forming leukocidins (Luk) including Panton-Valentine leukocidin, leukocidin ED, and gamma-hemolysin, and clumping factor A (ClfA), or an irrelevant isotype-matched control IgG (c-IgG), and then challenged with S. aureus. Rabbits challenged with S. aureus, but not those with saline, developed a hyperdynamic state of septic shock characterized by elevated cardiac output (CO), increased stroke volume (SV) and reduced systemic vascular resistance (SVR), which was followed by a lethal hypodynamic state characterized by rapid decline in mean arterial pressure (MAP), increased central venous pressure, reduced CO, reduced SV, elevated SVR, and reduced left-ventricular ejection fraction, thereby reproducing the hallmark clinical features of human staphylococcal septic shock. In this model, rabbits pretreated with anti-Hla/Luk/ClfA mAb combination had 69% reduction in mortality when compared to those pretreated with c-IgG (P<0.001). USA300-induced acute circulatory failure-defined as >70% decreased in MAP from pre-infection baseline-occurred in only 20% (2/10) of rabbits pretreated with anti-Hla/Luk/ClfA mAb combination compared to 100% (9/9) of those pretreated with c-IgG. Prophylaxis with anti-Hla/Luk/ClfA mAb combination halted progression to lethal hypodynamic shock, as evidenced by significant protection against the development of hyperlactatemia, hypocapnia, hyperkalemia, leukopenia, neutropenia, monocytopenia, lymphopenia, as well as biomarkers associated with acute myocardial injury. These results demonstrate the potential utility of a mechanically ventilated rabbit model that reproduced hallmark clinical features of hyperdynamic septic shock and the translational potential of immunotherapy targeting S. aureus virulence factors for the prevention of staphylococcal septic shock.

Ketone body 3-hydroxybutyrate elevates cardiac output through peripheral vasorelaxation and enhanced cardiac contractility

The ketone body 3-hydroxybutyrate (3-OHB) increases cardiac output and myocardial perfusion without affecting blood pressure in humans, but the cardiovascular sites of action remain obscure. Here, we test the hypothesis in rats that 3-OHB acts directly on the heart to increase cardiac contractility and directly on blood vessels to lower systemic vascular resistance. We investigate effects of 3-OHB on (a) in vivo hemodynamics using echocardiography and invasive blood pressure measurements, (b) isolated perfused hearts in Langendorff systems, and (c) isolated arteries and veins in isometric myographs. We compare Na-3-OHB to equimolar NaCl added to physiological buffers or injection solutions. At plasma concentrations of 2–4 mM in vivo, 3-OHB increases cardiac output (by 28.3±7.8%), stroke volume (by 22.4±6.0%), left ventricular ejection fraction (by 13.3±4.6%), and arterial dP/dtmax (by 31.9±11.2%) and lowers systemic vascular resistance (by 30.6±11.2%) without substantially affecting heart rate or blood pressure. Applied to isolated perfused hearts at 3–10 mM, 3-OHB increases left ventricular developed pressure by up to 26.3±7.4 mmHg and coronary perfusion by up to 20.2±9.5%. Beginning at 1–3 mM, 3-OHB relaxes isolated coronary (EC50=12.4 mM), cerebral, femoral, mesenteric, and renal arteries as well as brachial, femoral, and mesenteric veins by up to 60% of pre-contraction within the pathophysiological concentration range. Of the two enantiomers that constitute racemic 3-OHB, D-3-OHB dominates endogenously; but tested separately, the enantiomers induce similar vasorelaxation. We conclude that increased cardiac contractility and generalized systemic vasorelaxation can explain the elevated cardiac output during 3-OHB administration. These actions strengthen the therapeutic rationale for 3-OHB in heart failure management.

Efectos del reto de líquidos sobre el acople ventrículo arterial en un biomodelo porcino de choque endotóxico

Introduction: fluid challenges (FCs) consist of measuring hemodynamic response through changes in cardiac output (CO) after fluid administration, although only measuring CO proves insufficient. Ventriculo-arterial coupling (V-A) (effective arterial elastance / tele-systolic elastance: E(a)/Ets) are variables used for a comprehensive cardiac and circulatory status appraisal. Objective: to evaluate V-A in an endotoxic shock bio-model by FCs. Materials and methods: an endotoxic shock bio-model (9 pigs). Hemodynamic variables were measured every hour from time 0 (T0) to T6. Five FCs were performed between T0 and T4. Hypotension time was referred to as HT. The median differences in variables between T0-T4 were calculated. Challenges were classified into two groups according to V-A delta (post-challenge V-A - pre-challenge V-A). In ΔV-A≤0 o&gt;0, variables were measured before and after each FC. The lactate to pyruvate (L/P) ratio was determined at T0, T3 and T6. Correlations between the LP T6-T0 difference and hemodynamic variables, were established. Results: V-A increased (1.58 to 2,02, p=0.042) as Eae increased (1.74 to 2.55; p=0.017). CO (4.32 to 5.46, p=0.032) and cardiac power (CP) (0.61 to 0.77, p=0,028) increased, in the ΔV-AC≤0 group. The ΔLP correlated with the systolic and diastolic shock index (r=0.73), but not with V-A. Conclusion: V-A increased significantly during endotoxic shock. The ΔAVA≤0 group, showed elevated CO and CP during FC. ΔLP did not correlate with any of the V-A variables.

A mathematical model of vascular and hemodynamics changes in early and late forms of preeclampsia.

Preeclampsia-eclampsia syndrome is a leading cause of maternal mortality. The precise etiology of preeclampsia is still not well-defined and different forms exist, including early and late forms or preeclampsia, which may arise via distinctly different mechanisms. Low-dose aspirin administered at the end of the first trimester in women identified as high risk has been shown to reduce the incidence of early, but not late, preeclampsia; however, current risk factors show only fair predictive capability. There is a pressing need to develop accurate descriptions for the different forms of preeclampsia. This paper presents 1D fluid, solid, growth, and remodeling models for pregnancies complicated with early and late forms of preeclampsia. Simulations affirm a broad set of literature results that early forms of preeclampsia are characterized by elevated uterine artery pulsatility index (UA-PI) and total peripheral resistance (TPR) and lower cardiac output (CO), with modestly increased mean arterial blood pressure (MAP) in the first half of pregnancy, with elevation of TPR and MAP beginning at 20 weeks. Conversely, late forms of preeclampsia are characterized by only slightly elevated UA-PI and normal pre-term TPR, and slightly elevated MAP and CO throughout pregnancy, with increased TPR and MAP beginning after 34 weeks. Results suggest that preexisting arterial stiffness may be elevated in women that develop both early forms and late forms of preeclampsia; however, data that verify these results are lacking in the literature. Pulse wave velocity increases in early- and late-preeclampsia, coincident with increases in blood pressure; however, these increases are mainly due to the strain-stiffening response of larger arteries, rather than arterial remodeling-derived changes in material properties. These simulations affirm that early forms of preeclampsia may be associated with abnormal placentation, whereas late forms may be more closely associated with preexisting maternal cardiovascular factors; simulations also highlight several critical gaps in available data.

Does altered thyroid hormone status affect resting systolic blood pressure significantly in premenopausal women? - A cross-sectional comparative study

Background: Hypothyroid or hyperthyroid state affects all the physiological systems including cardiovascular system, central nervous system, digestive system, and blood. Among all adverse changes, systolic blood pressure (SBP) can also be affected in patients with thyroid disorders. Aims and Objectives: The present study was carried out to compare SBP in newly diagnosed patients of hypothyroidism, hyperthyroidism and age and gender matched euthyroid subjects and to assess correlation between Tri-iodothyronine (T3) level and resting SBP. Materials and Methods: The present study was carried out in 90 female subjects in the age group of 30 to 45 years. Diagnosis of hypothyroidism and hyperthyroidism was based on both clinical and biochemical criteria. Subjects were divided in euthyroid, hypothyroid and hyperthyroid groups with each group containing 30 subjects. Resting SBP was measured in all the groups. Results: Hyperthyroid group had significantly higher SBP as compared to euthyroid group and hypothyroid group. The difference in SBP between euthyroid and hypothyroid group was statistically non-significant. There was a significant correlation between Total T3 level and resting SBP. Conclusion: Elevated levels of thyroid hormone increases the cardiac output by increasing heart rate and increasing force of contraction. This elevated cardiac output in hyperthyroid subject is reflected as increase in resting SBP. Hence, thyroid hormone concentration should be kept within normal limits by appropriate therapeutic measures so as to prevent ill effects of resultant elevated SBP.

Abstract 10098: Assessment of a Rate Pressure Product Target During Stress Echocardiograms in Patients With Advanced Cirrhosis

Introduction: Dobutamine and exercise stress echo are routinely performed on patients with advanced cirrhosis though have low sensitivity in this patient population, even when target heart rate is achieved. This is in part due to their unique cardiovascular physiology which is frequently marked by reduced peripheral vascular resistance with low blood pressure, impaired chronotropic response to stress, hyperdynamic left ventricular systolic function and elevated cardiac output. In the general population, achieving a rate pressure product (RPP), defined as peak systolic blood pressure multiplied by peak heart rate, &gt; 25,000 is typically considered a high level of stress and is an adequate workload to detect ischemia, however this has not been validated in patients with advanced cirrhosis. We aimed to assess the impact of achieving a RPP &gt; 25,000 on the ability of stress echo to detect obstructive coronary artery disease (CAD) in patients with advanced cirrhosis. Methods: We performed a case-control study on patients with advanced cirrhosis where 88 had and 97 did not have CAD based on invasive coronary angiography. A total of 159 patients (85.9%, 77 with CAD and 82 without) had dobutamine and 26 (14.1%, 11 with CAD and 15 without) had exercise as their stress modality. Continuous variables were compared by means of Wilcoxon Rank Sum test. Categorical variables were expressed as numbers and percentages and compared by means of chi-square and Fisher exact tests. Results: The average maximum RPP was 19,999 ± 4,969.4 with 32 patients (17.3%) achieving a RPP &gt; 25,000 (14 with and 18 without CAD, P = 0.63). The average percent of maximum predicted HR (MPHR) achieved was 86.7 ± 9.2% with 136 patients (73.5%) achieving &gt; 85% of MPHR. Achieving a maximum RPP &gt; 25,000 (OR 0.83, 95% CI 0.39 - 1.79, P = 0.63) or a MPHR &gt; 85% (OR 1.04, 95% CI 0.54 - 1.99, P = 0.92) did not improve the ability of stress echo to detect obstructive CAD. Conclusions: Achieving a maximum RPP &gt; 25,000 did not improve the ability of stress echo to detect obstructive CAD in patients with advanced cirrhosis.

Cardiovascular consequences of sickle cell disease.

Sickle cell disease (SCD) is an inherited blood disorder caused by a single point mutation within the beta globin gene. As a result of this mutation, hemoglobin polymerizes under low oxygen conditions causing red blood cells to deform, become more adhesive, and increase in rigidity, which affects blood flow dynamics. This process leads to enhanced red blood cell interactions with the endothelium and contributes to vaso-occlusion formation. Although traditionally defined as a red blood cell disorder, individuals with SCD are affected by numerous clinical consequences including stroke, painful crisis episodes, bone infarctions, and several organ-specific complications. Elevated cardiac output, endothelium activation along with the sickling process, and the vaso-occlusion events pose strains on the cardiovascular system. We will present a review of the cardiovascular consequences of sickle cell disease and show connections with the vasculopathy related to SCD. We will also highlight biophysical properties and engineering tools that have been used to characterize the disease. Finally, we will discuss therapies for SCD and potential implications on SCD cardiomyopathy.

The effect of impedance cardiography directed antihypertensive therapy on fetal growth restriction rates and perinatal mortality in women with chronic hypertension.

We sought to determine the effect of impedance cardiography directed medical antihypertensive therapy on fetal growth restriction and perinatal mortality in women with chronic hypertension. A retrospective study was conducted on 958 women referred to the Maternal Hypertension Center at Cabell Huntington Hospital between 2005 and 2014 for the indication of chronic hypertension. Serial assessments of maternal hemodynamics were obtained using non-invasive impedance cardiography. Vasodilators were initiated for increased systemic vascular resistance. Elevated cardiac output was treated with beta blockade. Blood pressure at initial visit was used to stratify patients into five groups. Initial blood pressure of <130 systolic or <80 diastolic had 24 cases of growth restriction (6.8%) and 6 perinatal deaths (1.7%), 130-139 systolic or 80-89 diastolic resulted in 29 cases of growth restriction (9.3%) and 9 perinatal deaths (2.9%), 140-149 systolic or 90-99 diastolic 14 cases of growth restriction (6.5%) and 3 perinatal deaths (1.4%), 150-159 systolic or 100-109 diastolic had 5 cases of growth restriction (8.6%) and 4 perinatal deaths (6.89%), and >160 systolic or >110 diastolic 3 cases of growth restriction (13%) with no perinatal deaths. There were no differences in growth restriction (p=.59) or perinatal death (p=.15) between the groups. The rates of IUGR and perinatal mortality did not increase even with increasing severity of maternal hypertension. This low cost and non-invasive test should be considered for optimizing rates of growth restriction and perinatal mortality in pregnancies complicated by chronic hypertension.

Cardiodynamic Profiles of Gravidas with Obesity in Early Gestation

Background Obesity is a significant contributor to adverse maternal and perinatal outcomes, increasing the risk of spontaneous miscarriage, stillbirth, preterm delivery, fetal malformations, gestational diabetes, fetal macrosomia, cesarean section, maternal thromboembolic complications, and hypertensive complications. Historical data indicate that nonpregnant individuals with obesity typically have an elevated cardiac output, increase in total and central blood volume, and low peripheral vascular resistance. Studies measuring hemodynamic parameters in pregnant patients with obesity is lacking. Methods A retrospective study was conducted in 796 pregnant patients referred to the Maternal Hypertension Center at Cabell Huntington Hospital; 335 had a Body Mass Index (BMI) of &lt; 30kg/m2, 171 had a BMI of 30kg/m2 - 34.9kg/m2, 154 had a BMI of 35kg/m2 - 39.9kg/m2, and 136 had a BMI &gt;4 40kg/m2. Results The maternal hemodynamic parameters showed significant differences in systolic blood pressure (p value &lt;.01), mean arterial pressure (p value = 0.01), cardiac output (p value &lt;0.01), and systemic vascular resistance (p value &lt;0.01). There were no significant differences in maternal heart rate (p value = 0.2093) or diastolic blood pressure between groups (p value = 0.1139). Conclusion Non-invasive hemodynamic testing offers the opportunity to further explore pathologic cardiovascular alterations of pregnant patients with obesity. Further research is needed to categorize hemodynamic parameters, with an attempt to explore potential interventions to improve pregnancy outcomes for gravidas with obesity.

Vasoplegia Following Complex Spine Surgery: Incidence and Risk.

Retrospective cohort study. Vasoplegia is a life-threatening form of distributive or vasodilatory shock that is characterized by reduced systemic vascular resistance with resultant hypotension and normal to elevated cardiac output affecting morbidity and mortality. Vasoplegia in the context of Spine Surgery has not been described previously. The purpose of this case series is to determine incidence, risk factors, complications and postoperative outcome in patients with vasoplegia after complex multi-level thoraco-lumbar spine surgery. A retrospective review of the electronic medical records at our institution was conducted between January 2014 and June 2018. All patients undergoing multi-level spine surgery (>6 levels) were screened for intraoperative hypotension. Patient demographics, surgical characteristics, neurological status, blood loss, risk factors, medical treatment, complications, hospital course and mortality were collected. All patients included in this study had a minimum follow-up period of 3 months. Out of 8521 surgically treated patients, 994 patients with multi-level thoraco-lumbar spine surgery were identified. A total of 41 patients had intraoperative hypotensive events. Of those, 5 patients with vasoplegia could be identified after elimination of all other potential contributing factors. Vasoplegia did not influence the neurological outcome. One major and three minor complications occurred. All patients showed full recovery. The risk factors identified for vasoplegia include prolonged surgery with osteotomies. Vasoplegia is a rare condition with an incidence of .6%. Patients experiencing vasoplegia did not appear to experience worse surgical outcomes. The use of special intraoperative hemodynamic monitoring should be considered in selected cases.