Beta-block the septic heart

Ivabradine in Septic Shock: A Narrative Review

In patients with septic shock, compensatory tachycardia initially serves to maintain adequate cardiac output and tissue oxygenation but may persist despite appropriate fluid and vasopressor resuscitation. This sustained elevation in heart rate and altered heart rate variability, indicative of autonomic dysfunction, is a well-established independent predictor of adverse outcomes in critical illness. Elevated heart rate exacerbates myocardial oxygen demand, reduces ventricular filling time, compromises coronary perfusion during diastole, and impairs the isovolumetric relaxation phase of the cardiac cycle, contributing to ventricular-arterial decoupling. This also leads to increased ventricular and atrial filling pressures, with a heightened risk of arrhythmias. Ivabradine, a highly selective inhibitor of the sinoatrial node's pacemaker current (If or "funny" current), mitigates heart rate by modulating diastolic depolarization slope without affecting contractility. By exerting a selective chronotropic effect devoid of negative inotropic properties, ivabradine shows potential for improving hemodynamics in septic shock patients with cardiac dysfunction. This review evaluates the plausible mechanisms and existing evidence regarding the utility of ivabradine in managing patients with septic shock.

Exploring the Impact of Prior Beta-Blocker and Calcium Channel Blocker Usage on Clinical Outcomes in Critically Ill Patients With Sepsis: An Observational Study

Background Sepsis is associated with increased Ca++ levels in many cell types that can cause cytotoxicity and cell death through multiple mechanisms. In patients with sepsis, limiting beta-adrenergic stimulation may also be beneficial. The intense adrenergic stimulation of sepsis results in cardiac and extra-cardiac effects. In the intensive care unit (ICU), the question of whether to continue calcium channel blockers (CCBs) and beta-blockers in patients with sepsis who were using these medications before ICU admission is of significant concern. Methodology In this prospective observational study, we have included 114 patients who met the inclusion criteria of being diagnosed as having sepsis, aged 18 to 65 years, and expected to stay in the ICU for more than 72 hours. These patients were divided into three groups: group 1 consisted of patients taking CCBs before admission, group 2 included those taking beta-blockers before admission, and group 3 served as the control group, comprising patients who had not taken either of these medications before admission. Disease severity in the ICU was assessed and documented by the Sequential Organ Failure Assessment (SOFA) score. Clinical outcomes among three groups were compared regarding the need for vasopressor support, serum procalcitonin (PCT), serum lactate, serum quantitative C-reactive protein (qCRP), SOFA score, and 28 days mortality. Parametric data were expressed as mean ± standard deviation. The Kruskal-Wallis test was used to analyze parametric data between the two groups and among three groups. Results Mortality was found lower in group 1 (21.05%) and group 2 (26.31%) than in group 3 (47.36%), and this association was found to be statistically significant (P = 0.033). We also found a significant difference in mortality between groups 1 and 3 (P = 0.015) and no significant difference between groups 2 and 3 (P = 0.057). Mortality was found to be significantly associated with high SOFA scores on days 1, 3, and 7. Conclusions From the aforementioned results, we concluded that the mortality rate in patients with sepsis was improved when they were pretreated with beta-blockers or CCBs before admission to the ICU and that medication should be continued if not contraindicated in the ICU course.

Ageing and the Autonomic Nervous System

The vertebrate nervous system is divided into central (CNS) and peripheral (PNS) components. In turn, the PNS is divided into the autonomic (ANS) and enteric (ENS) nervous systems. Ageing implicates time-related changes to anatomy and physiology in reducing organismal fitness. In the case of the CNS, there exists substantial experimental evidence of the effects of age on individual neuronal and glial function. Although many such changes have yet to be experimentally observed in the PNS, there is considerable evidence of the role of ageing in the decline of ANS function over time. As such, this chapter will argue that the ANS constitutes a paradigm for the physiological consequences of ageing, as well as for their clinical implications.

EvaLuation of early CRRT and beta-blocker InTervention in patients with ECMO (ELITE) trial: study protocol for a 2 × 2 partial factorial randomized controlled trial

Background

In critically ill patients requiring extracorporeal membrane oxygenation (ECMO) therapy, early initiation of continuous renal replacement therapy (CRRT) and beta-blockade of catecholamine-induced inotropic effects may improve outcomes.

Methods

A 2 × 2 partial factorial randomized controlled trial in eligible ECMO patients without a clear indication or contraindication to either intervention is centrally randomly assigned to (A) early or conventional-indicated CRRT and/or (B) beta-blocker or usual care. The primary outcome is all-cause mortality at 30 days for both arms. A total of 496 participants provides 80% power to determine a 20% risk reduction in mortality at 30 days with 5% type I error.

Discussion

This trial will help define the role of early CRRT and beta-blockade in ECMO patients. There have been 89 patients enrolled at 10 hospitals in study A and is ongoing. However, study B was stopped in August 2019 in the absence of any patients being enrolled.

Trial registration

ClinicalTrials.govNCT03549923. Registered on 8 June 2018. World Health Organization International Clinical Trials Registry Platform (WHO ICTEP) network. The Ethics Committee of Beijing Anzhen Hospital Approval ID is 2018013.

Troponin I Cutoff for Non-ST-Segment Elevation Myocardial Infarction in Sepsis

The diagnostic value and optimal cutoff level of cardiac troponin I in patients with sepsis have not been studied. In this single hospital retrospective study, we assessed the optimal cutoff value of troponin I for diagnosing non-ST-segment elevation myocardial infarction (NSTEMI) with type 1 myocardial infarction (MI) in patients with sepsis who had undergone a percutaneous coronary intervention from 2009 to 2019. In total, 5,341 patients (excluding patients with chronic kidney disease) were included, of whom 277 had sepsis or septic shock. Of the 123 patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS) and sepsis, 77 (62.6%) were diagnosed with NSTEMI with type 1 MI. The receiver-operating characteristic curve showed an area under the curve (AUC) of 0.705 for diagnosis of NSTEMI with type 1 MI with a troponin I cutoff of >300 ng/L (sensitivity: 68.4%, specificity: 70.2%, Youden index: 0.386). Multiple linear regression showed no significant predictors of NSTEMI with type 1 MI. Troponin level and the Global Registry of Acute Coronary Events (GRACE) scores were correlated (R² = 0.0625, p = 0.032) and showed comparable predictive value for 6-month mortality (AUC: 0.637 and 0.611, respectively, p = 0.7651). The optimal troponin I cutoff to effectively diagnose NSTEMI with type 1 MI in patients with sepsis was 300 ng/L.

Evaluation of efficacy and safety of esmolol in treating patients with septic shock: A protocol for systematic review and meta-analysis

BACKGROUND

In septic shock cases, tachycardia and a hyperdynamic hemodynamic profile are characteristics of the condition. It has been reported that using beta antagonist esmolol constitutes a form of treatment to reduce heart rate to improve diastolic filling time and elevate cardiac output, which reduces vasopressor support. Still, there are controversial results. Therefore, in this study, the primary objective is to perform a meta-analysis by systematically evaluating the efficiency and security of using esmolol to treat septic shocks.

METHODS

A systematic literature search for relevant randomized controlled trials that report evaluations on the efficiency and safety of using esmolol to treat septic shock patients from their inception to February 2022 will be conducted in three databases containing publications in Chinese language (WanFang, Chinese BioMedical Literature Database, and China National Knowledge Infrastructure) and four databases containing English language publications (Cochrane Library, PubMed, Web of Science, and EMBASE). The screening of the relevant studies will be performed by a pair of authors independently, and the screening involves examining the title, abstract and full-text stages, data extraction, and bias risk assessment. The results are summarized through the fixed-effects and random-effects models, the respective models will be utilized for data pooling according to the heterogeneity of studies that will be included. Moreover, publication bias is assessed if more than ten studies are considered.

RESULTS

The results are a high-quality synthesis of the most recent evidence for esmolol usage in septic shock treatment.

CONCLUSION

Up-to-date evidence will be provided through the results of this systematic review related to assessing the efficacy and safeness of esmolol usage in treating septic shock.

ETHICS AND DISSEMINATION

Ethical permissions are not required as prepublished data are used.

OSF REGISTRATION NUMBER

DOI 10.17605/OSF.IO/SKEZ7.

Immunohistochemistry in the Postmortem Diagnosis of Sepsis: A Systematic Review

It is not uncommon for the forensic pathologist to question whether a deceased person had experienced sepsis that could have either been the cause of or contributed to the person's death. Often, the missing typical pathologic factors or lack of clinical and circumstantial information on the death render the autopsy of a sepsis-related death a difficult task for the forensic pathologist. Several authors emphasize on how an immunohistochemical analysis could help in diagnosing death related to sepsis. The research we carried out analyzes the main scientific studies in the literature, primarily the tracing of 21 immunohistochemical antigens evaluated to help diagnose death related to sepsis. The purpose of this review was to analyze and summarize the markers studied until now and to consider the limitations of immunohistochemistry that currently exist with regard to this particular field of forensic pathology. Immunohistochemistry provided interesting and promising results, but further studies are needed in order for them to be confirmed, so that they may be applied in standard forensic practice.

The autonomic nervous system in septic shock and its role as a future therapeutic target: a narrative review

The autonomic nervous system (ANS) regulates the cardiovascular system. A growing body of experimental and clinical evidence confirms significant dysfunction of this regulation during sepsis and septic shock. Clinical guidelines do not currently include any evaluation of ANS function during the resuscitation phase of septic shock despite the fact that the severity and persistence of ANS dysfunction are correlated with worse clinical outcomes. In the critical care setting, the clinical use of ANS-related hemodynamic indices is currently limited to preliminary investigations trying to predict and anticipate imminent clinical deterioration. In this review, we discuss the evidence supporting the concept that, in septic shock, restoration of ANS-mediated control of the cardiovascular system or alleviation of the clinical consequences induced by its dysfunction (e.g., excessive tachycardia, etc.), may be an important therapeutic goal, in combination with traditional resuscitation targets. Recent studies, which have used standard and advanced monitoring methods and mathematical models to investigate the ANS-mediated mechanisms of physiological regulation, have shown the feasibility and importance of monitoring ANS hemodynamic indices at the bedside, based on the acquisition of simple signals, such as heart rate and arterial blood pressure fluctuations. During the early phase of septic shock, experimental and/or clinical studies have shown the efficacy of negative-chronotropic agents (i.e., beta-blockers or ivabradine) in controlling persistent tachycardia despite adequate resuscitation. Central α-2 agonists have been shown to prevent peripheral adrenergic receptor desensitization by reducing catecholamine exposure. Whether these new therapeutic approaches can safely improve clinical outcomes remains to be confirmed in larger clinical trials. New technological solutions are now available to non-invasively modulate ANS outflow, such as transcutaneous vagal stimulation, with initial pre-clinical studies showing promising results and paving the way for ANS modulation to be considered as a new potential therapeutic target in patients with septic shock.

An update on levosimendan in acute cardiac care: applications and recommendations for optimal efficacy and safety

Introduction: In the 20 years since its introduction to the palette of intravenous hemodynamic therapies, the inodilator levosimendan has established itself as a valuable asset for the management of acute decompensated heart failure. Its pharmacology is notable for delivering inotropy via calcium sensitization without an increase in myocardial oxygen consumption.Areas covered: Experience with levosimendan has led to its applications expanding into perioperative hemodynamic support and various critical care settings, as well as an array of situations associated with acutely decompensated heart failure, such as right ventricular failure, cardiogenic shock with multi-organ dysfunction, and cardio-renal syndrome. Evidence suggests that levosimendan may be preferable to milrinone for patients in cardiogenic shock after cardiac surgery or for weaning from extracorporeal life support and may be superior to dobutamine in terms of short-term survival, especially in patients on beta-blockers. Positive effects on kidney function have been noted, further differentiating levosimendan from catecholamines and phosphodiesterase inhibitors.Expert opinion:Levosimendan can be a valuable resource in the treatment of acute cardiac dysfunction, especially in the presence of beta-blockers or ischemic cardiomyopathy. When attention is given to avoiding or correcting hypovolemia and hypokalemia, an early use of the drug in the treatment algorithm is preferred.

Use of Levosimendan in Intensive Care Unit Settings: An Opinion Paper

Levosimendan is an inodilator that promotes cardiac contractility primarily through calcium sensitization of cardiac troponin C and vasodilatation via opening of adenosine triphosphate–sensitive potassium (K_ATP) channels in vascular smooth muscle cells; the drug also exerts organ-protective effects through a similar effect on mitochondrial K_ATP channels. This pharmacological profile identifies levosimendan as a drug that may have applications in a wide range of critical illness situations encountered in intensive care unit medicine: hemodynamic support in cardiogenic or septic shock; weaning from mechanical ventilation or from extracorporeal membrane oxygenation; and in the context of cardiorenal syndrome. This review, authored by experts from 9 European countries (Austria, Belgium, Czech republic, Finland, France, Germany, Italy, Sweden, and Switzerland), examines the clinical and experimental data for levosimendan in these situations and concludes that, in most instances, the evidence is encouraging, which is not the case with other cardioactive and vasoactive drugs routinely used in the intensive care unit. The size of the available studies is, however, limited and the data are in need of verification in larger controlled trials. Some proposals are offered for the aims and designs of these additional studies.

Effect of landiolol on sex-related transcriptomic changes in the myocardium during sepsis

Objectives

The aims of this study are to better understand phenotypic differences between male and female rats during sepsis, to characterise the contribution of the beta1-adrenergic blocker landiolol to septic cardiomyopathy and to determine why landiolol induces divergent effects in males and females.

Methods

The myocardial transcriptional profiles in male and female Wistar rats were assessed after the induction of sepsis by cecal ligation and puncture and addition of landiolol.

Results

Our results showed major differences in the biological processes activated during sepsis in male and female rats. In particular, a significant decrease in processes related to cell organisation, contractile function, ionic transport and phosphoinositide-3-kinase/AKT (PI3K/AKT) signalling was observed only in males. The transcript of ATPase sarcoplasmic/endoplasmic reticulum Ca²⁺ transporting 3 (SERCA3) was sex-differently regulated. In males, landiolol reversed several signalling pathways dysregulated during sepsis. The expression level of genes encoding tubulin alpha 8 (TUBA8) and myosin heavy chain 7B (MYH7) contractile proteins, phosphatase 2 catalytic subunit alpha (PPP2CA), G protein-coupled receptor kinase 5 (GRK5) and A-kinase anchoring protein 6 (AKAP6) returned to their basal levels. In contrast, in females, landiolol had limited effects.

Conclusion

In males, landiolol reversed the expression of many genes that were deregulated in sepsis. Conversely, sepsis-induced deregulation of gene expression was less pronounced in females than in males, and was maintained in the landiolol-treated females. These findings highlight important sex-related differences and confirm previous observations on the important benefit of landiolol intake on cardiac function in male rats.

Electronic supplementary material

The online version of this article (10.1186/s40635-019-0263-0) contains supplementary material, which is available to authorized users.

[Atrial fibrillation in patients with sepsis and non-cardiac infections]

Atrial fibrillation (AF) is by far the most frequent cardiac arrhythmia associated with sepsis and infections. Newly occurring AF due to infections is associated with a deterioration of the prognosis for acute events and also for the long-term prognosis of patients. The risk of developing AF during an infection depends on general (e.g. age, structural heart disease) as well as infection-specific risk factors (e.g. sepsis severity, vasopressor treatment). Current guidelines do not make specific recommendations on the treatment of infection-associated AF and very few prospective data are available. The use of beta blockers appears to be safe for both prevention and frequency control of AF even in patients requiring catecholamines. For specific antiarrhythmic treatment, the use of class I antiarrhythmic agents is conceivable as an alternative to the predominantly used amiodarone. Newly occurring AF within infections has long been considered a specific entity with a low risk of recurrence, so that only a small proportion of patients received long-term effective anticoagulation; however, data from large retrospective studies suggest significantly higher recurrence rates. Therefore, the question of whether this group of patients benefits from long-term effective anticoagulation and extended monitoring of arrhythmia should be the subject of future research.

Effects of esmolol on systemic hemodynamics and heart rate variability measured using the Analgesia/Nociception Index in resuscitated piglets with Pseudomonas aeruginosa septic shock

OBJECTIVE

To determine the effects of esmolol on hemodynamics and heart rate variability (HRV) in the early stage of sepsis.

DESIGN

Prospective, randomized, controlled, parallel trial.

SETTINGS

Veterinary research laboratory.

ANIMALS

Ten anesthetized piglets.

INTERVENTIONS

Septic shock was induced by infusing a suspension of live Pseudomonas aeruginosa IV in 10 anesthetized piglets. The piglets were resuscitated according to a standardized protocol using Ringer's lactate solution, norepinephrine, and milrinone. Once stabilized, the piglets were randomized to receive IV esmolol, titrated to a heart rate <90/min, or control, receiving saline. A pulmonary artery catheter and an arterial catheter were inserted for hemodynamic measurements. The Analgesia/Nociception Index (ANI) and the normalized HRV frequency domain parameters - high-frequency (HF), low frequency (LF), LF/HF ratio - were recorded using a proprietary monitor.

MEASUREMENTS AND MAIN RESULTS

A significant decrease in cardiac output and heart rate, and a significant increase in systemic vascular resistance were observed over time in the esmolol group in comparison to the control group. No other differences were observed in hemodynamic parameters. No significant differences were observed in ANI variations or HRV parameters over time between groups.

CONCLUSIONS

The administration of esmolol produced significant changes in hemodynamics with no change in ANI values or HRV parameters. Further study is needed to understand the effect of esmolol during sepsis.

Analysis on sarcoglycans expression as markers of septic cardiomyopathy in sepsis-related death

The post-mortem assessment of sepsis-related death can be carry out by many methods recently suggested as microbiological and biochemical investigations. In these cases, the cause of death is a multiple organ dysfunction due to a dysregulated inflammatory response occurring after the failure of infection control process. It was highlighted also that the heart can be a target organ in sepsis which determines the so-called septic cardiomyopathy characterized by myocardial depression. Several mechanisms to explain the pathophysiology of septic cardiomyopathy were suggested, but very few studies about the structural alterations of cardiac cells responsible for myocardial depression were carried out. The aim of this study was to evaluate whether sarcoglycans (SG) were involved in septic cardiac damage analyzing their expression in sepsis-related deaths and, particularly, if these proteins can be used as markers of septic myocardial dysfunction. Cases of septic-related death confirmed by clinical and autopsy records were investigated and compared to a control group of traumatic deaths. Indirect immunofluorescence analysis was performed to analyze α-SG, β-SG, δ-SG, ζ-SG, ε-SG, and γ-SG. Decrease of fluorescence staining pattern for all tested sarcoglycans was observed in the septic-related deaths compared to normal fluorescence staining pattern of control group. These results provide new findings about the myocytes structural alterations due to sepsis and suggest that these proteins could be used in forensic assessment of septic cardiomyopathy.

If Channel Inhibition With Ivabradine Does Not Improve Cardiac and Vascular Function in Experimental Septic Shock

OBJECTIVE

Previous studies have suggested that lowering heart rate (HR) by selective β1-blockers improves sepsis-induced cardiac and vascular dysfunction primarily by decreasing proinflammatory pathways. However, the impact of isolated heart rate reduction (HRR) on hemodynamics and inflammatory pathways remains unknown. The present study was designed to assess the effects of HRR by ivabradine, an If channel inhibitor, on cardiovascular function and inflammatory pathways in peritonitis-induced septic shock in rats.

DESIGN

Randomized animal study.

SETTING

University research laboratory.

INTERVENTIONS

Four hours after cecal ligation and puncture (CLP), Wistar rats were randomly allocated to the following groups: CLP (n = 8) and CLP + ivabradine (n = 8, administered per os 4 h after the surgery). Another eight Wistar male rats underwent sham operation. All rats received a continuous infusion of saline (10 mL kg h), analgesic (nalbuphine: 0.2 mg kg h), and antibiotics (imipenem and cilastatin sodium: 10 mg kg) 4 h after the surgery. Assessment at 18 h included hemodynamics, in vivo cardiac function by echocardiography, and ex vivo vasoreactivity by myography. Circulating cytokine levels (TNF-α, IL-6, and IL-10) were measured by ELISA, whereas cardiac and vascular protein expressions of NF-κB/IκBα/iNOS and Akt/eNOS were assessed by Western blotting.

RESULTS

Compared with sham animals, CLP induced tachycardia, hypotension, decreased cardiac output, hyperlactatemia, and vascular hyporesponsiveness to vasopressors. Compared with the CLP group, adjunction of ivabradine decreased the HR without any impact on blood pressure, lactatemia, or vascular responsiveness to vasopressors. Adjunction of ivabradine to CLP rats had no impact on TNF-α, IL-6, and IL-10 cytokines, or on the protein expression levels of phosphorylated forms of NF-κB, Akt, eNOS, and degradation of IκBα in cardiac and vascular tissues.

CONCLUSION

Isolated HRR by ivabradine in an experimental model of septic shock does not appear to be associated with any effect on the tested parameters of cardiac function or on vascular responsiveness to vasopressors. Moreover, in this setting, ivabradine does not alter the circulating levels of selected pro/anti-inflammatory cytokines or cardiac and vascular NF-κB/IκBα protein expression levels.

The apelinergic system as an alternative to catecholamines in low-output septic shock

Catecholamines, in concert with fluid resuscitation, have long been recommended in the management of septic shock. However, not all patients respond positively and controversy surrounding the efficacy-to-safety profile of catecholamines has emerged, trending toward decatecholaminization. Contextually, it is time to re-examine the “maintaining blood pressure” paradigm by identifying safer and life-saving alternatives. We put in perspective the emerging and growing knowledge on a promising alternative avenue: the apelinergic system. This target exhibits invaluable pleiotropic properties, including inodilator activity, cardio-renal protection, and control of fluid homeostasis. Taken together, its effects are expected to be greatly beneficial for patients in septic shock.

Landiolol for managing atrial fibrillation in intensive care

Landiolol is an injectable ultrashort acting beta-blocker with high beta1 selectivity indicated for heart rate control of atrial fibrillation in the emergency and critical care setting. Accordingly, landiolol is associated with a significantly reduced risk of arterial hypotension and negative inotropic effects. Based on this particular profile along with the clinical experience in Japan for more than a decade landiolol represents a promising agent for the management of elevated heart rate and atrial fibrillation in intensive care patients even with catecholamine requirements. This article provides a review and perspective of landiolol for heart rate control in intensive care patients based on the current literature.

The immune system's role in sepsis progression, resolution, and long-term outcome

Sepsis occurs when an infection exceeds local tissue containment and induces a series of dysregulated physiologic responses that result in organ dysfunction. A subset of patients with sepsis progress to septic shock, defined by profound circulatory, cellular, and metabolic abnormalities, and associated with a greater mortality. Historically, sepsis-induced organ dysfunction and lethality were attributed to the complex interplay between the initial inflammatory and later anti-inflammatory responses. With advances in intensive care medicine and goal-directed interventions, early 30-day sepsis mortality has diminished, only to steadily escalate long after "recovery" from acute events. As so many sepsis survivors succumb later to persistent, recurrent, nosocomial, and secondary infections, many investigators have turned their attention to the long-term sepsis-induced alterations in cellular immune function. Sepsis clearly alters the innate and adaptive immune responses for sustained periods of time after clinical recovery, with immune suppression, chronic inflammation, and persistence of bacterial representing such alterations. Understanding that sepsis-associated immune cell defects correlate with long-term mortality, more investigations have centered on the potential for immune modulatory therapy to improve long-term patient outcomes. These efforts are focused on more clearly defining and effectively reversing the persistent immune cell dysfunction associated with long-term sepsis mortality.

Efficacy and Safety of Esmolol in Treatment of Patients with Septic Shock

Background:

Previous studies have suggested that β1-receptor blockers benefit septic shock patients. This study aimed to determine whether β1-receptor blockers benefit tissue perfusion in sepsis and to identify parameters to reduce the risk of this drug in sepsis.

Methods:

Consecutive septic shock patients were recruited from the Intensive Care Unit of Peking Union Medical College Hospital within 48 h of diagnosis. All patients were hemodynamically stable and satisfactorily sedated with a heart rate (HR) ≥100 beats/min. Esmolol therapy achieved the target HR of 10–15% lower than the baseline HR. Clinical and physiological data of patients were collected prospectively within 1 h prior to esmolol therapy and 2 h after achieving the targeted HR.

Results:

Sixty-three patients were recruited. After esmolol therapy, blood pressure was unaltered, whereas stroke volume (SV) was increased compared with before esmolol therapy (43.6 ± 22.7 vs. 49.9 ± 23.7 ml, t = −2.3, P = 0.047). Tissue perfusion, including lactate levels (1.4 ± 0.8 vs. 1.1 ± 0.6 mmol/L, t = 2.6, P = 0.015) and the central venous-to-arterial carbon dioxide difference (5.6 ± 3.3 vs. 4.3 ± 2.2 mmHg, t = 2.6 P = 0.016), was also significantly decreased after esmolol therapy. For patients with increased SV (n = 42), cardiac efficiency improved, and esmolol therapy had a lower risk for a decrease in cardiac output (CO). Therefore, pretreatment cardiac systolic and diastolic parameters with (n = 42)/without (n = 21) an increase in SV were compared. Mitral lateral annular plane systolic excursion (MAPSElat) in patients with increased SV was significantly higher than that in those without increased SV (1.3 ± 0.3 vs. 1.1 ± 0.2 cm, t = 2.4, P = 0.034).

Conclusions:

SV of septic shock patients is increased following esmolol therapy. Although CO is also decreased with HR, tissue perfusion is not worse. MAPSElat can be used to predict an increase in SV before esmolol use.

Trial Registration:

ClinicalTrials.gov, NCT01920776; https://clinicaltrials.gov/ct2/show/NCT01920776?term=NCT01920776&rank=1.

Sepsis-induced cardiac dysfunction and β-adrenergic blockade therapy for sepsis

Despite recent advances in medical care, mortality due to sepsis, defined as life-threatening organ dysfunction caused by a dysregulated host response to infection, remains high. Fluid resuscitation and vasopressors are the first-line treatment for sepsis in order to optimize hemodynamic instability caused by vasodilation and increased vascular permeability. However, these therapies, aimed at maintaining blood pressure and blood flow to vital organs, could have deleterious cardiac effects, as cardiomyocyte damage occurs in the early stages of sepsis. Recent experimental and clinical studies have demonstrated that a number of factors contribute to sepsis-induced cardiac dysfunction and the degree of cardiac dysfunction is one of the major prognostic factors of sepsis. Therefore, strategies to prevent further cardiomyocyte damage could be of crucial importance in improving the outcome of sepsis. Among many factors causing sepsis-induced cardiac dysfunction, sympathetic nerve overstimulation, due to endogenous elevated catecholamine levels and exogenous catecholamine administration, is thought to play a major role. β-adrenergic blockade therapy is widely used for ischemic heart disease and chronic heart failure and in the prevention of cardiovascular events in high-risk perioperative patients undergoing major surgery. It has also been shown to restore cardiac function in experimental septic animal models. In a single-center randomized controlled trial, esmolol infusion in patients with septic shock with persistent tachycardia reduced the 28-day mortality. Furthermore, it is likely that β-adrenergic blockade therapy may result in further beneficial effects in patients with sepsis, such as the reduction of inflammatory cytokine production, suppression of hypermetabolic status, maintenance of glucose homeostasis, and improvement of coagulation disorders. Recent accumulating evidence suggests that β-adrenergic blockade could be an attractive therapy to improve the prognosis of sepsis. We await a large multicenter randomized clinical trial to confirm the beneficial effects of β-adrenergic blockade therapy in sepsis, of which mortality is still high.

Effects of low doses of esmolol on cardiac and vascular function in experimental septic shock

Background

Administration of a selective β1-blocker, such as esmolol, in human septic shock has demonstrated cardiovascular protective effects related to heart rate reduction. Certain experimental data also indicate that esmolol exerts systemic anti-inflammatory and beneficial effects on vascular tone. Thus, the present study aimed to determine whether a non-chronotropic dose of esmolol maintains its protective cardiovascular and anti-inflammatory effects in experimental septic shock.

Methods

Four hours after cecal ligation and puncture (CLP), Wistar male rats were randomly allocated to the following groups (n = 8): CLP, CLP + E-1 (esmolol: 1 mg.kg⁻¹.h⁻¹), CLP + E-5 (esmolol: 5 mg.kg⁻¹.h⁻¹), CLP + E-18 (esmolol: 18 mg.kg⁻¹.h⁻¹). An additional eight rats underwent sham operation. All rats received a continuous infusion of saline, analgesic and antibiotics 4 hours after the surgery. Assessment at 18 hours included in vivo cardiac function assessed by echocardiography and ex vivo vasoreactivity assessed by myography. Circulating cytokine levels (IL-6 and IL-10) were measured by ELISA. Cardiac and vascular protein expressions of p-NF-κB, IκBα, iNOS, p-AKT/AKT and p-eNOS/eNOS were assessed by western blotting.

Results

CLP induced tachycardia, hypotension, cardiac output reduction, hyperlactatemia and vascular hypo-responsiveness to vasopressors. Compared to CLP animals, heart rate was unchanged in CLP + E-1 and CLP + E-5 but was reduced in CLP + E-18. Stroke volume, cardiac output, mean arterial pressure and lactatemia were improved in CLP + E-1 and CLP + E-5, while vascular responsiveness to phenylephrine was only improved in CLP + E-5 and CLP + E-18. Plasma IL-6 levels were decreased in all esmolol groups. p-NF-κB was decreased in both cardiac and vascular tissues in CLP + E-5 and CLP + E-18.

Conclusion

In experimental septic shock, low doses of esmolol still improved cardiac function and vasoreactivity. These benefits appear to be associated with a modulation of inflammatory pathways.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-016-1580-2) contains supplementary material, which is available to authorized users.

Effects of dexmedetomidine and esmolol on systemic hemodynamics and exogenous lactate clearance in early experimental septic shock

BACKGROUND

Persistent hyperlactatemia during septic shock is multifactorial. Hypoperfusion-related anaerobic production and adrenergic-driven aerobic generation together with impaired lactate clearance have been implicated. An excessive adrenergic response could contribute to persistent hyperlactatemia and adrenergic modulation might be beneficial. We assessed the effects of dexmedetomidine and esmolol on hemodynamics, lactate generation, and exogenous lactate clearance during endotoxin-induced septic shock.

METHODS

Eighteen anesthetized and mechanically ventilated sheep were subjected to a multimodal hemodynamic/perfusion assessment including hepatic and portal vein catheterizations, total hepatic blood flow, and muscle microdialysis. After monitoring, all received a bolus and continuous infusion of endotoxin. After 1 h they were volume resuscitated, and then randomized to endotoxin-control, endotoxin-dexmedetomidine (sequential doses of 0.5 and 1.0 μg/k/h) or endotoxin-esmolol (titrated to decrease basal heart rate by 20 %) groups. Samples were taken at four time points, and exogenous lactate clearance using an intravenous administration of sodium L-lactate (1 mmol/kg) was performed at the end of the experiments.

RESULTS

Dexmedetomidine and esmolol were hemodynamically well tolerated. The dexmedetomidine group exhibited lower epinephrine levels, but no difference in muscle lactate. Despite progressive hypotension in all groups, both dexmedetomidine and esmolol were associated with lower arterial and portal vein lactate levels. Exogenous lactate clearance was significantly higher in the dexmedetomidine and esmolol groups.

CONCLUSIONS

Dexmedetomidine and esmolol were associated with lower arterial and portal lactate levels, and less impairment of exogenous lactate clearance in a model of septic shock. The use of dexmedetomidine and esmolol appears to be associated with beneficial effects on gut lactate generation and lactate clearance and exhibits no negative impact on systemic hemodynamics.

The Modification Effect of Influenza Vaccine on Prognostic Indicators for Cardiovascular Events after Acute Coronary Syndrome: Observations from an Influenza Vaccination Trial

Introduction. The prognosis of acute coronary syndrome (ACS) patients has been improved with several treatments such as antithrombotics, beta-blockers, and angiotensin-converting enzyme inhibitors (ACEI) as well as coronary revascularization. Influenza vaccination has been shown to reduce adverse outcomes in ACS, but no information exists regarding the interaction of other treatments. Methods. This study included 439 ACS patients from Phrommintikul et al. A single dose of inactivated influenza vaccine was given by intramuscular injection in the vaccination group. The cardiovascular outcomes were described as major cardiovascular events (MACEs) which included mortality, hospitalization due to ACS, and hospitalization due to heart failure (HF). The stratified and multivariable Cox's regression analysis was performed. Results. The stratified Cox's analysis by influenza vaccination for each cardiovascular outcome and discrimination of hazard ratios showed that beta-blockers had an interaction with influenza vaccination. Moreover, the multivariable hazard ratios disclosed that influenza vaccine is associated with a significant reduction of hospitalization due to HF in patients who received beta-blockers (HR = 0.05, 95% CI = 0.004–0.71, P = 0.027), after being adjusted for prognostic indicators (sex, dyslipidemia, serum creatinine, and left ventricular ejection fraction). Conclusions. The influenza vaccine was shown to significantly modify the effect of beta-blockers in ACS patients and to reduce the hospitalization due to HF. However, further study of a larger population and benefits to HF patients should be investigated.

Shock Management for Cardio-surgical Intensive Care Unit Patient: The Silver Days

Shock in cardio-surgical intensive care unit (ICU) patients requires prompt identification of the underlying condition and timely therapeutic interventions. Management during the first 6 hours, also referred to as "the golden hours", is of paramount importance to reverse the shock state and improve the patient's outcome. The authors have previously described a state-of-the-art diagnostic work-up and discussed how to optimise preload, vascular tone, contractility, heart rate and oxygen delivery during this phase. Ideally, shock can be reversed during this initial period. However, some patients might have developed multiple organ dysfunction, which persists beyond the first 6 hours despite the early haemodynamic treatment goals having been accomplished. This period, also referred to as "the silver days", is the focus of this review. The authors discuss how to reduce vasopressor load and how to minimise adrenergic stress by using alternative inotropes, extracorporeal life-support and short acting beta-blockers. The review incorporates data on fluid weaning, safe ventilation, daily interruption of sedation, delirium management and early rehabilitation. It includes practical recommendations in areas where the evidence is scarce or controversial. Although the focus is on cardio-surgery ICU patients, most of the considerations apply to critical ill patients in general.

β1-Adrenergic Inhibition Improves Cardiac and Vascular Function in Experimental Septic Shock

OBJECTIVE

Preliminary experimental data suggest that selective β1-blockers may improve ex vivo cardiac function in animal sepsis. Currently, the effects of esmolol on in vivo cardiac function and on vascular function are unknown. The present study was designed to examine the effects of the β1-selective blocker esmolol on myocardial and vascular function in peritonitis-induced septic rats and to explore the inflammatory pathways involved in this process.

DESIGN

Randomized animal study.

SETTING

University research laboratory.

SUBJECTS

Male Wistar rats.

INTERVENTIONS

Four hours after cecal ligation and puncture, Wistar rats were randomly allocated to the following groups: control, esmolol, norepinephrine (started at 18 hr after the surgery), and esmolol (started at 4 hr after the surgery) + norepinephrine (started at 18 hr after the surgery). Assessment at 18 hours after surgery was focused on cardiac contractility and vascular ex vivo function. Cardiac and vascular protein expressions of nuclear factor κB and endothelial nitric oxide synthase/Akt/inducible nitric oxide synthase pathways were assessed by Western blotting.

MEASUREMENTS AND MAIN RESULTS

When compared with sham-operated animals, cecal ligation and puncture animals developed hypotension, cardiac depression, and vascular hyporesponsiveness to vasopressor treatment. Esmolol infusion increased cardiac contractility and restored mesenteric vasoreactivity. This effect was associated with a decrease in nuclear factor κB activation, an increase in Akt and endothelial nitric oxide synthase phosphorylation, and a decrease in inducible nitric oxide synthase expression both at the cardiac and vessel level. Esmolol infusion was also associated with an up-regulation in α1-vascular adrenoreceptors.

CONCLUSION

Adjunction of selective β1-blockade to standard septic shock management enhances intrinsic cardiac contractility and vascular responsiveness to catecholamines. These protective cardiovascular effects are likely predominantly attributed to the anti-inflammatory effect of esmolol.

Is It Time to Beta Block the Septic Patient?

Beta blockers are some of the most studied drugs in the pharmacopoeia. They are already widely used in medicine for treating hypertension, chronic heart failure, tachyarrhythmias, and tremor. Whilst their use in the immediate perioperative patient has been questioned, the use of esmolol in the patients with established septic shock has been recently reported to have favourable outcomes. In this paper, we review the role of the adrenergic system in sepsis and the evidence for the use of beta stimulation and beta blockers from animal models to critically ill patients.

Phosphoinositide 3-kinase gamma controls inflammation-induced myocardial depression via sequential cAMP and iNOS signalling

AIMS

Sepsis-induced myocardial depression (SIMD), an early and frequent event of infection-induced systemic inflammatory response syndrome (SIRS), is characterized by reduced contractility irrespective of enhanced adrenergic stimulation. Phosphoinositide-3 kinase γ (PI3Kγ) is known to prevent β-adrenergic overstimulation via its scaffold function by activating major cardiac phosphodiesterases and restricting cAMP levels. However, the role of PI3Kγ in SIRS-induced myocardial depression is unknown. This study is aimed at determining the specific role of lipid kinase-dependent and -independent functions of PI3Kγ in the pathogenesis of SIRS-induced myocardial depression.

METHODS AND RESULTS

PI3Kγ knockout mice (PI3Kγ(-/-)), mice expressing catalytically inactive PI3Kγ (PI3Kγ(KD/KD)), and wild-type mice (P3Kγ(+/+)) were exposed to lipopolysaccharide (LPS)-induced systemic inflammation and assessed for survival, cardiac autonomic nervous system function, and left ventricular performance. Additionally, primary adult cardiomyocytes were used to analyse PI3Kγ effects on myocardial contractility and inflammatory response. SIRS-induced adrenergic overstimulation induced a transient hypercontractility state in PI3Kγ(-/-) mice, followed by reduced contractility. In contrast, P3Kγ(+/+) mice and PI3Kγ(KD/KD) mice developed an early and ongoing myocardial depression despite exposure to similarly increased catecholamine levels. Compared with cells from P3Kγ(+/+) and PI3Kγ(KD/KD) mice, cardiomyocytes from PI3Kγ(-/-) mice showed an enhanced and prolonged cAMP-mediated signalling upon norepinephrine and an intensified LPS-induced proinflammatory response characterized by nuclear factor of activated T-cells-mediated inducible nitric oxide synthase up-regulation.

CONCLUSIONS

This study reveals the lipid kinase-independent scaffold function of PI3Kγ as a mediator of SIMD during inflammation-induced SIRS. Activation of cardiac phosphodiesterases via PI3Kγ is shown to restrict myocardial hypercontractility early after SIRS induction as well as the subsequent inflammatory responses.

β-blockers in critically ill patients: from physiology to clinical evidence

This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency Medicine 2015 and co-published as a series in Critical Care. Other articles in the series can be found online at http://ccforum.com/series/annualupdate2015. Further information about the Annual Update in Intensive Care and Emergency Medicine is available from http://www.springer.com/series/8901.

Impact of β-adrenoceptor blockade on systemic inflammation and coagulation disturbances in rats with acute traumatic coagulopathy

BACKGROUND

Sympathetic hyperactivity occurs early in acute traumatic coagulopathy (ATC) and is closely related to its development. β-adrenoceptor antagonists are known to alleviate adverse sympathetic effects and improve outcome in various diseases. We investigated whether β-blockers have protective effects against inflammation and endothelial and hemostatic disorders in ATC.

MATERIAL AND METHODS

ATC was induced in male Sprague-Dawley rats by trauma and hemorrhagic shock. Rats were randomly assigned to the sham, ATCC (ATC control), and ATCB (ATC with beta-adrenoceptor blockade) groups. Rats were injected intraperitoneally with propranolol or vehicle at baseline. Heart rate variability (HRV) and markers of inflammation, coagulation, and endothelial activation were measured, and Western blotting analysis of nuclear factor (NF)-κB was done after shock. Separate ATCC and ATCB groups were observed to compare overall mortality.

RESULTS

HRV showed enhanced sympathetic tone in the ATCC group, which was reversed by propranolol. Propranolol attenuated the induction of pro-inflammatory cytokines TNF-α and IL-6, as well as fibrinolysis markers plasmin antiplasmin complex and tissue-type plasminogen activator. The increased serum syndecan-1 and soluble thrombomodulin were inhibited by propranolol, and the NF-κB expression was also decreased by propranolol pretreatment. But propranolol did not alter overall mortality in rats with ATC after shock.

CONCLUSIONS

Beta-adrenoceptor blockade can alleviate sympathetic hyperactivity and exert anti-inflammatory, anti-fibrinolysis, and endothelial protective effects, confirming its pivotal role in the pathogenesis of ATC. Its mechanism in ATC should be explored further.

Beta-blockers in septic shock: a review

In septic shock, high adrenergic stress is associated with cardiovascular and systemic adverse effects, which can negatively affect the results. Beta-adrenergic receptor block has been shown to be effective in controlling the disproportionate increase in heart rate, maintaining a favorable hemodynamic profile and apparently improving the efficiency of the cardiovascular system in order to maintain tissue perfusion. They have also been shown to modulate favorably catecholamine-induced immunosuppression and to decrease insulin resistance, protein catabolism, and proinflammatory cytokine expression associated with cardiovascular dysfunction. Selective beta-1 blockers appear to provide better results than non-selective blockers, even suggesting a positive impact on mortality. Future clinical trials are still needed to confirm these findings and define the scope of their benefits.

Inhibition of sepsis-induced inflammatory response by β1-adrenergic antagonists

BACKGROUND

Although previous studies have described potential benefits of nonselective β-adrenergic antagonist therapy in sepsis, there is a paucity of data on the use of β1-selective antagonists (B1AA). The purposes of this study were to describe the effects of B1AA on survival in septic animals and to explore for molecular mechanisms of potential treatment benefit.

METHODS

C57BL/6 male mice received intraperitoneal injection of lipopolysaccharide. Continuous infusion of a B1AA (esmolol) or an equal volume of saline (control) was initiated at 4 hours after injection. Kaplan-Meier survival analysis at 120 hours was used to explore for mortality differences. A subgroup of animals was sacrificed for microarray expression analysis. Top candidate genes were validated in vitro and in silico. Expression of our candidate genes in a human microarray database (GSE28750) was explored.

RESULTS

B1AA infusion resulted in increased survival (p = 0.001) at 120 hours. Mean survival difference was 23.6 hours (p = 0.002). Hazard ratio for mortality with B1AA is 0.43 (95% confidence interval, 0.26-0.72). Immunologic disease (p = 0.0003-0.036) and cell death/survival (p = 0.0001-0.042) were significantly associated with improved survival in septic mice treated with B1AA. Further analysis of the gene structure revealed that eight genes shared common promoter activating sequence for NFKB and/or BRCA1 motifs. Analysis of a human sepsis database identified the up-regulation of CAMP (p = 0.032) and TNFSF10 (p = 0.001) genes in septic patients compared with healthy controls.

CONCLUSION

Continuous infusion of a B1AA initiated after septic insult improves survival at 5 days in a murine model. Benefits may be caused by modulation of gene expression in immunologic pathways leading to an increase in CAMP and TNFSF10 expression. This observed effect may be explained by the activation of NFKB and BRCA1 genes involved in immune response and cell repair pathways. Our findings support further investigation of the use of B1AA in the treatment of sepsis.

Early diastolic dysfunction is associated with intensive care unit mortality in cancer patients presenting with septic shock

BACKGROUND

Cancer patients present a high risk of sepsis and are exposed to cardiotoxic drugs during chemotherapy. Myocardial dysfunction is common during septic shock and can be evaluated at bedside using echocardiography. The aim of this study was to identify early cardiac dysfunctions associated with intensive care unit (ICU) mortality in cancer patients presenting with septic shock.

METHODS

Seventy-two cancer patients admitted to the ICU underwent echocardiography within 48 h of developing septic shock. History of malignancies, anticancer treatments, and clinical characteristics were prospectively collected.

RESULTS

ICU mortality was 48%. Diastolic dysfunction (e' ≤8 cm s(-1)) was an independent echocardiographic parameter associated with ICU mortality {odds ratio (OR) 7.7 [95% confidence interval (CI), 2.58-23.38]; P<0.001}. Overall, three factors were independently associated with ICU mortality: sepsis-related organ failure assessment score at admission [OR 1.35 ( 95% CI, 1.05-1.74); P=0.017], occurrence of diastolic dysfunction [OR 16.6 (95% CI, 3.28-84.6); P=0.001], and need for conventional mechanical ventilation [OR 16.6 (95% CI, 3.6-77.15); P<0.001]. Diastolic dysfunction was not associated with exposure to cardiotoxic drugs.

CONCLUSIONS

Early diastolic dysfunction is a strong and independent predictor of mortality in cancer patients presenting with septic shock. It is not associated with exposure to cardiotoxic drugs. Further studies incorporating monitoring of diastolic function and therapeutic interventions improving cardiac relaxation need to be evaluated in cancer patients presenting with septic shock.

Early propranolol treatment induces lung heme-oxygenase-1, attenuates metabolic dysfunction, and improves survival following experimental sepsis

Introduction

Pharmacological agents that block beta-adrenergic receptors have been associated with improved outcome in burn injury. It has been hypothesized that injuries leading to a hypermetabolic state, such as septic shock, may also benefit from beta-blockade; however, outcome data in experimental models have been contradictory. Thus, we investigated the effect of beta-blockade with propranolol on survival, hemodynamics, lung heat shock protein (HSP) expression, metabolism and inflammatory markers in a rat cecal ligation and puncture (CLP) model of sepsis.

Methods

Sprague-Dawley rats receiving either repeated doses (30 minutes pre-CLP and every 8 hours for 24 hours postoperatively) of propranolol or control (normal saline), underwent CLP and were monitored for survival. Additionally, lung and blood samples were collected at 6 and 24 hours for analysis. Animals also underwent monitoring to evaluate global hemodynamics.

Results

Seven days following CLP, propranolol improved survival versus control (P < 0.01). Heart rates in the propranolol-treated rats were approximately 23% lower than control rats (P < 0.05) over the first 24 hours, but the mean arterial blood pressure was not different between groups. Metabolic analysis of lung tissue demonstrated an increase in lung ATP/ADP ratio and NAD+ content and a decreased ratio of polyunsaturated fatty acids to monounsaturated fatty acids (PUFA/MUFA). Cytokine analysis of the inflammatory cytokine tumor necrosis factor alpha (TNF-alpha) demonstrated decreased expression of TNF-alpha in both lung and plasma at 24 hours post CLP induced sepsis. Finally, propranolol led to a significant increase in lung hemeoxygenase-1 expression, a key cellular protective heat shock protein (HSP) in the lung. Other lung HSP expression was unchanged.

Conclusions

These results suggest that propranolol treatment may decrease mortality during sepsis potentially via a combination of improving metabolism, suppressing aspects of the inflammatory response and enhancing tissue protection.

Initial fractal exponent of heart rate variability is associated with success of early resuscitation in patients with severe sepsis or septic shock: a prospective cohort study

INTRODUCTION

Heart rate variability (HRV) reflects autonomic nervous system tone as well as the overall health of the baroreflex system. We hypothesized that loss of complexity in HRV upon intensive care unit (ICU) admission would be associated with unsuccessful early resuscitation of sepsis.

METHODS

We prospectively enrolled patients admitted to ICUs with severe sepsis or septic shock from 2009 to 2011. We studied 30 minutes of electrocardiogram, sampled at 500 Hz, at ICU admission and calculated heart rate complexity via detrended fluctuation analysis. Primary outcome was vasopressor independence at 24 hours after ICU admission. Secondary outcome was 28-day mortality.

RESULTS

We studied 48 patients, of whom 60% were vasopressor independent at 24 hours. Five (10%) died within 28 days. The ratio of fractal alpha parameters was associated with both vasopressor independence and 28-day mortality (P = .04) after controlling for mean heart rate. In the optimal model, Sequential Organ Failure Assessment score and the long-term fractal α parameter were associated with vasopressor independence.

CONCLUSIONS

Loss of complexity in HRV is associated with worse outcome early in severe sepsis and septic shock. Further work should evaluate whether complexity of HRV could guide treatment in sepsis.

Lipoteichoic acid from Staphylococcus aureus directly affects cardiomyocyte contractility and calcium transients

Lipoteichoic acid (LTA) is the key pathogenic factor of gram-positive bacteria and contributes significantly to organ dysfunction in sepsis, a frequent complication in critical care patients. We hypothesized that LTA directly affects cardiomyocyte function, thus contributing to cardiac failure in sepsis. This study was designed to evaluate the effects of LTA on contractile properties and calcium-transients of isolated adult rat cardiomyocytes. When myocytes were exposed to LTA for 1h prior to analysis, the amplitudes of calcium-transients as well as sarcomere shortening increased to 130% and 142% at 1 Hz stimulation frequency. Relengthening of sarcomeres as well as decay of calcium-transients was accelerated after LTA incubation. Exposure to LTA for 24 h resulted in significant depression of calcium-transients as well as of sarcomere shortening compared to controls. One of the major findings of our experiments is that LTA most likely affects calcium-handling of the cardiomyocytes. The effect is exacerbated by reduced extracellular calcium, which resembles the clinical situation in septic patients. Functionally, an early stimulating effect of LTA with increased contractility of the cardiomyocytes may be an in vitro reflection of early hyperdynamic phases in clinical sepsis. Septic disorders have been shown to induce late hypodynamic states of the contractile myocardium, which is also supported at the single-cell level in vitro by results of our 24h-exposure to LTA.

The cardiopulmonary effects of vasopressin compared with norepinephrine in septic shock

BACKGROUND

Vasopressin is known to be an effective vasopressor in the treatment of septic shock, but uncertainty remains about its effect on other hemodynamic parameters.

METHODS

We examined the cardiopulmonary effects of vasopressin compared with norepinephrine in 779 adult patients with septic shock recruited to the Vasopressin and Septic Shock Trial. More detailed cardiac output data were analyzed for a subset of 241 patients managed with a pulmonary artery catheter, and data were collected for the first 96 h after randomization. We compared the effects of vasopressin vs norepinephrine in all patients and according to severity of shock (< 15 or ≥ 15 μg/min of norepinephrine) and cardiac output at baseline.

RESULTS

Equal BPs were maintained in both treatment groups, with a significant reduction in norepinephrine requirements in the patients treated with vasopressin. The major hemodynamic difference between the two groups was a significant reduction in heart rate in the patients treated with vasopressin (P <.0001), and this was most pronounced in the less severe shock stratum (treatment × shock stratum interaction, P =.03). There were no other major cardiopulmonary differences between treatment groups, including no difference in cardiac index or stroke volume index between patients treated with vasopressin and those treated with norepinephrine. There was significantly greater use of inotropic drugs in the vasopressin group than in the norepinephrine group.

CONCLUSIONS

Vasopressin treatment in septic shock is associated with a significant reduction in heart rate but no change in cardiac output or other measures of perfusion.

TRIAL REGISTRY

ISRCTN Register; No.: ISRCTN94845869; URL: www.isrctn.org

Stress-related cardiomyopathies

Stress-related cardiomyopathies can be observed in the four following situations: Takotsubo cardiomyopathy or apical ballooning syndrome; acute left ventricular dysfunction associated with subarachnoid hemorrhage; acute left ventricular dysfunction associated with pheochromocytoma and exogenous catecholamine administration; acute left ventricular dysfunction in the critically ill. Cardiac toxicity was mediated more by catecholamines released directly into the heart via neural connection than by those reaching the heart via the bloodstream. The mechanisms underlying the association between this generalized autonomic storm secondary to a life-threatening stress and myocardial toxicity are widely discussed. Takotsubo cardiomyopathy has been reported all over the world and has been acknowledged by the American Heart Association as a form of reversible cardiomyopathy. Four "Mayo Clinic" diagnostic criteria are required for the diagnosis of Takotsubo cardiomyopathy: 1) transient left ventricular wall motion abnormalities involving the apical and/or midventricular myocardial segments with wall motion abnormalities extending beyond a single epicardial coronary artery distribution; 2) absence of obstructive epicardial coronary artery disease that could be responsible for the observed wall motion abnormality; 3) ECG abnormalities, such as transient ST-segment elevation and/or diffuse T wave inversion associated with a slight troponin elevation; and 4) the lack of proven pheochromocytoma and myocarditis. ECG changes and LV dysfunction occur frequently following subarachnoid hemorrhage and ischemic stroke. This entity, referred as neurocardiogenic stunning, was called neurogenic stress-related cardiomyopathy. Stress-related cardiomyopathy has been reported in patients with pheochromocytoma and in patients receiving intravenous exogenous catecholamine administration. The role of a huge increase in endogenous and/or exogenous catecholamine level in critically ill patients (severe sepsis, post cardiac resuscitation, post tachycardia) to explain the onset of myocardial dysfunction was discussed. Further research is needed to understand this complex interaction between heart and brain and to identify risk factors and therapeutic and preventive strategies.