Pharmacological inhibition of GSK-3β produces late phase of cardioprotection in hyperlipidemic rat: possible involvement of HSP 72

PM2.5-Induced Cardiac Structural Modifications and Declined Pro-Survival Signalling Pathways Are Responsible for the Inefficiency of GSK-3β Inhibitor in Attenuating Myocardial Ischemia-Reperfusion Injury in Rats

Circulatory GSK3β is recognized as a biomarker and therapeutic target for diseases, including myocardial diseases. However, its potential as a target for myocardial ischemia-reperfusion injury (IR) in the presence of PM2.5 exposure is unclear. Wistar rats underwent IR following either a 21-day or single exposure to PM2.5 at a concentration of 250 µg/m3. The effects of GSK3β inhibitor on cardiac physiology, tissue injury, mitochondrial function, and the PI3K/AKT/GSK3β signalling axis were examined. The inhibitor was not effective in improving hemodynamics or reducing IR-induced infarction in the myocardium exposed to PM2.5 for 21 days. However, for a single-day exposure, the inhibitor showed potential in mitigating cardiac injury. In normal hearts undergoing IR, the inhibitor activated the PI3K/AKT signalling pathway, improved mitochondrial function, and reduced oxidative stress. These positive effects were not observed in PM2.5-exposed rats. Furthermore, the inhibitor stimulated autophagy in hearts exposed to PM2.5 for 21 days and subjected to IR, resulting in increased mTOR expression and decreased AMPK expression. In normal hearts and those exposed to a single dose of PM2.5, the inhibitor effectively activated the PI3K/Akt/AMPK axis. These findings suggest that GSK3β may not be a reliable therapeutic target for IR in the presence of chronic PM2.5 exposure.

Preclinical multi-target strategies for myocardial ischemia-reperfusion injury

Despite promising breakthroughs in diagnosing and treating acute coronary syndromes, cardiovascular disease’s high global mortality rate remains indisputable. Nearly half of these patients died of ischemic heart disease. Primary percutaneous coronary intervention (PCI) and coronary artery bypass grafting can rapidly restore interrupted blood flow and become the most effective method for salvaging viable myocardium. However, restoring blood flow could increase the risk of other complications and myocardial cell death attributed to myocardial ischemia-reperfusion injury (IRI). How to reduce the damage of blood reperfusion to ischemic myocardium has become an urgent problem to be solved. In preclinical experiments, many treatments have substantial cardioprotective effects against myocardial IRI. However, the transition from these cardioprotective therapies to clinically beneficial therapies for patients with acute myocardial infarction remains elusive. The reasons for the failure of the clinical translation may be multi-faceted, and three points are summarized here: (1) Our understanding of the complex pathophysiological mechanisms of myocardial IRI is far from enough, and the classification of specific therapeutic targets is not rigorous, and not clear enough; (2) Most of the clinical patients have comorbidities, and single cardioprotective strategies including ischemia regulation strategies cannot exert their due cardioprotective effects under conditions of hyperglycemia, hypertension, hyperlipidemia, and aging; (3) Most preclinical experimental results are based on adult, healthy animal models. However, most clinical patients had comorbidities and received multiple drug treatments before reperfusion therapy. In 2019, COST Action proposed a multi-target drug combination initiative for prospective myocardial IRI; the optimal cardioprotective strategy may be a combination of additive or synergistic multi-target therapy, which we support. By establishing more reasonable preclinical models, screening multi-target drug combinations more in line with clinical practice will benefit the translation of clinical treatment strategies.

Quercetin: A Bioactive Compound Imparting Cardiovascular and Neuroprotective Benefits: Scope for Exploring Fresh Produce, Their Wastes, and By-Products

Quercetin, a bioactive secondary metabolite, holds incredible importance in terms of bioactivities, which has been proved by in vivo and in vitro studies. The treatment of cardiovascular and neurological diseases by quercetin has been extensively investigated over the past decade. Quercetin is present naturally in appreciable amounts in fresh produce (fruits and vegetables). However, today, corresponding to the growing population and global demand for fresh fruits and vegetables, a paradigm shift and focus is laid towards exploring industrial food wastes and/or byproducts as a new resource to obtain bioactive compounds such as quercetin. Based on the available research reports over the last decade, quercetin has been suggested as a reliable therapeutic candidate for either treating or alleviating health issues, mainly those of cardiovascular and neurological diseases. In the present review, we have summarized some of the critical findings and hypotheses of quercetin from the available databases foreseeing its future use as a potential therapeutic agent to treat cardiovascular and neurological diseases. It is anticipated that this review will be a potential reference material for future research activities to be undertaken on quercetin obtained from fresh produce as well as their respective processing wastes/byproducts that rely on the circular concept.

Influence of cardiometabolic comorbidities on myocardial function, infarction, and cardioprotection: Role of cardiac redox signaling

The morbidity and mortality from cardiovascular diseases (CVD) remain high. Metabolic diseases such as obesity, hyperlipidemia, diabetes mellitus (DM), non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) as well as hypertension are the most common comorbidities in patients with CVD. These comorbidities result in increased myocardial oxidative stress, mainly from increased activity of nicotinamide adenine dinucleotide phosphate oxidases, uncoupled endothelial nitric oxide synthase, mitochondria as well as downregulation of antioxidant defense systems. Oxidative and nitrosative stress play an important role in ischemia/reperfusion injury and may account for increased susceptibility of the myocardium to infarction and myocardial dysfunction in the presence of the comorbidities. Thus, while early reperfusion represents the most favorable therapeutic strategy to prevent ischemia/reperfusion injury, redox therapeutic strategies may provide additive benefits, especially in patients with heart failure. While oxidative and nitrosative stress are harmful, controlled release of reactive oxygen species is however important for cardioprotective signaling. In this review we summarize the current data on the effect of hypertension and major cardiometabolic comorbidities such as obesity, hyperlipidemia, DM, NAFLD/NASH on cardiac redox homeostasis as well as on ischemia/reperfusion injury and cardioprotection. We also review and discuss the therapeutic interventions that may restore the redox imbalance in the diseased myocardium in the presence of these comorbidities.

Quercetin Reverses Cardiac Systolic Dysfunction in Mice Fed with a High-Fat Diet: Role of Angiogenesis

Global consumption of high-fat diets (HFD) is associated with an increased incidence of cardiometabolic syndrome and cardiac injury, warranting identification of cardioprotective strategies. Cardioprotective effects of quercetin (Q) have mostly been evaluated in ischemic heart disease models and attributed to senolysis. We hypothesized that Q could alleviate murine cardiac damage caused by HFD by restoring the myocardial microcirculation. C57BL/6J mice were fed standard chow or HFD for 6 months and then treated with Q (50 mg/kg) or vehicle 5-day biweekly for 10 additional weeks. Left ventricular (LV) cardiac function was studied in vivo using magnetic resonance imaging, and intramyocardial fat deposition, microvascular density, oxidative stress, and senescence were analyzed ex vivo. Additionally, direct angiogenic effects of Q were studied in vitro in HUVECs. HFD increased body weight, heart weight, total cholesterol, and triglyceride levels, whereas Q normalized heart weight and triglycerides. LV ejection fraction was lower in HFD vs. control mice (56.20 ± 15.8% vs. 73.38 ± 5.04%, respectively, P < 0.05), but improved in HFD + Q mice (67.42 ± 7.50%, P < 0.05, vs. HFD). Q also prevented cardiac fat accumulation and reduced HFD-induced cardiac fibrosis, cardiomyocyte hypertrophy, oxidative stress, and vascular rarefaction. Cardiac senescence was not observed in any group. In vitro, ox-LDL reduced HUVEC tube formation activity, which Q effectively improved. Quercetin may directly induce angiogenesis and decrease myocardial oxidative stress, which might account for its cardioprotective effects in the murine HFD-fed murine heart independently from senolytic activity. Furthermore, its beneficial effects might be partly attributed to a decrease in plasma triglycerides and intramyocardial fat deposition.

Potential Implications of Quercetin and its Derivatives in Cardioprotection

Quercetin (QCT) is a natural polyphenolic compound enriched in human food, mainly in vegetables, fruits and berries. QCT and its main derivatives, such as rhamnetin, rutin, hyperoside, etc., have been documented to possess many beneficial effects in the human body including their positive effects in the cardiovascular system. However, clinical implications of QCT and its derivatives are still rare. In the current paper we provide a complex picture of the most recent knowledge on the effects of QCT and its derivatives in different types of cardiac injury, mainly in ischemia-reperfusion (I/R) injury of the heart, but also in other pathologies such as anthracycline-induced cardiotoxicity or oxidative stress-induced cardiac injury, documented in in vitro and ex vivo, as well as in in vivo experimental models of cardiac injury. Moreover, we focus on cardiac effects of QCT in presence of metabolic comorbidities in addition to cardiovascular disease (CVD). Finally, we provide a short summary of clinical studies focused on cardiac effects of QCT. In general, it seems that QCT and its metabolites exert strong cardioprotective effects in a wide range of experimental models of cardiac injury, likely via their antioxidant, anti-inflammatory and molecular pathways-modulating properties; however, ageing and presence of lifestyle-related comorbidities may confound their beneficial effects in heart disease. On the other hand, due to very limited number of clinical trials focused on cardiac effects of QCT and its derivatives, clinical data are inconclusive. Thus, additional well-designed human studies including a high enough number of patients testing different concentrations of QCT are needed to reveal real therapeutic potential of QCT in CVD. Finally, several negative or controversial effects of QCT in the heart have been reported, and this should be also taken into consideration in QCT-based approaches aimed to treat CVD in humans.

A Comorbidity Model of Myocardial Ischemia/Reperfusion Injury and Hypercholesterolemia in Rat Cardiac Myocyte Cultures

Introduction

The use of comorbidity models is crucial in cardioprotective drug development. Hypercholesterolemia causes endothelial and myocardial dysfunction, as well as aggravates ischemia/reperfusion (I/R)-induced myocardial injury. Endogenous cardioprotective mechanisms against I/R are impaired in hyperlipidemic and hyperglycemic in vivo animal models. Therefore, our aim was to develop a medium throughput comorbidity cell-based test system of myocardial I/R injury, hypercholesterolemia and hyperglycemia that mimics comorbidity conditions.

Methods

Cardiac myocytes isolated from neonatal or adult rat hearts were cultured in control or in three different hypercholesterolemic media with increasing cholesterol content (hiChol) or hiChol + hyperglycemic medium, respectively. Each group was then subjected to simulated ischemia/reperfusion (SI/R) or corresponding normoxic condition, respectively. Cholesterol uptake was tested by Filipin staining in neonatal cardiac myocytes. Cell viability, total cell count and oxidative stress, i.e., total reactive oxygen species (ROS) and superoxide level were measured by fluorescent assays.

Results

Neonatal cardiac myocytes took up cholesterol from the different hiChol media at a concentration-dependent manner. In normoxia, viability of hiChol neonatal cardiac myocytes was not significantly changed, however, superoxide levels were increased as compared to vehicle. After SI/R, the viability of hiChol neonatal cardiac myocytes was decreased and total ROS level was increased as compared to vehicle. HiChol combined with hyperglycemia further aggravated cell death and oxidative stress in normoxic as well as in SI/R conditions. Viability of hiChol adult cardiac myocytes was significantly decreased and superoxide level was increased in normoxia and these changes were further aggravated by SI/R. HiChol combined with hyperglycemia further aggravated cell death, however level of oxidative stress increased only in normoxic condition.

Conclusion

HiChol rat cardiac myocytes showed reduction of cell viability and increased oxidative stress, which were further aggravated by SI/R and with additional hyperglycemia. This is the first demonstration that the combination of the current hypercholesterolemic medium and SI/R in cardiac myocytes mimics the cardiac pathology of the comorbid heart with I/R and hypercholesterolemia.

Critical Limb Ischaemia Exacerbates Mitochondrial Dysfunction in ApoE-/- Mice Compared with ApoE+/+ Mice, but N-acetyl Cysteine still Confers Protection

OBJECTIVES

The current study was performed in order to determine the influence of hypercholesterolaemia on critical limb ischaemia (CLI) and whether targeting oxidative stress by antioxidant therapies such as N-acetyl cysteine (NAC), considered to be a direct scavenger of reactive oxygen species, could confer muscle protection.

METHODS

Apolipoprotein E (ApoE)-/- mice (n = 9, 29 weeks old) and their genetic controls ApoE+/+ mice (n = 9, 29 weeks old) were submitted to sequential right femoral and iliac ligations; the left limb served as control. ApoE+/+ mice were divided into two groups: Group 1 (n = 4) and Group 2 (n = 5); as well as ApoE-/- mice: Group 3 (n = 3), and Group 4 (n = 6). NAC treatment was administered to Groups 2 and 4 in drinking water. Mice were sacrificed on Day 40 and gastrocnemius muscles were harvested to study mitochondrial respiration by oxygraphy, calcium retention capacity by spectrofluorometry, and production of reactive oxygen species by electron paramagnetic resonance.

RESULTS

CLI associated with ApoE deficiency resulted in more severe mitochondrial dysfunction: maximum oxidative capacity and calcium retention capacity were decreased (-42.9% vs. -25.1%, p = .010; and -73.1% vs. -40.3%, p = .003 respectively) and production of reactive oxygen species was enhanced (+63.6% vs. +41.4%, p = .03) in ApoE-/- mice compared with ApoE+/+ mice respectively. Antioxidant treatment restored oxidative capacity, calcium retention capacity and decreased production of reactive oxygen species in both mice strands.

CONCLUSIONS

In this small murine study, hypercholesterolaemia exacerbated mitochondrial dysfunction, as clinically expected; but antioxidant therapy appeared protective, which is counter to clinical experience. Further work is clearly needed.

Preoperative oral thyroid hormones to prevent euthyroid sick syndrome and attenuate myocardial ischemia-reperfusion injury after cardiac surgery with cardiopulmonary bypass in children: A randomized, double-blind, placebo-controlled trial

BACKGROUND

Both euthyroid sick syndrome and myocardial ischemia-reperfusion injury are common and have been significantly associated with morbidity and mortality after pediatric cardiac surgery with cardiopulmonary bypass. This single-center, prospective, double-blind, randomized placebo-controlled clinical pilot trial was designed to assess if preoperative oral thyroid hormone therapy could prevent the occurrence of euthyroid sick syndrome (ESS) and attenuate myocardial ischemia-reperfusion injury (IRI) after cardiac surgery with cardiopulmonary bypass (CPB) in children.

METHODS

Forty children aged 3 to 12 year, scheduled for elective congenital heart disease repair surgery with CPB, were randomized into 2 groups of equal size to receive the following treatments in a double-blind manner: placebo (control group) and thyroid tablet 0.4 mg/kg (trial group) taken orally once a day for 4 days before surgery. The perioperative serum thyroid hormone levels and hemodynamic variables were determined. The extubation time, duration of intensive care unit (ICU) stay, and use of inotropic drugs in the ICU were recorded. The myocardial expressions of heat shock protein 70 (HSP70), myosin heavy chain (MHC) mRNA, and thyroid hormone receptor (TR) mRNA were detected. The serum creatine kinase-MB (CK-MB) activity and troponin I (TnI) positive ratio at 24 hour after surgery were assessed.

RESULTS

There were no significant differences in hemodynamic variables at all observed points, extubation time, and duration of ICU stay between groups. As compared with baselines on administration, serum triiodothyronine (T3) and free T3 (FT3) levels on the first, second, and fourth postoperative day, and serum thyrotropic-stimulating hormone (TSH), tetraiodothyronine (T4), and free T4 (FT4) levels on the first postoperative day were significantly decreased in the 2 groups. Serum T3, FT3, and T4 levels on the first and second postoperative day, and serum FT4 level on the first postoperative day were significantly higher in the trial group than in control group. As compared with the control group, the number of patients requiring inotropic drugs in the ICU, serum CK-MB activity, serum positive TnI ratio, and myocardial expression of MHCβ mRNA were significantly decreased, and myocardial expressions of both HSP70 and MHCα mRNA were significantly increased in the trial group.

CONCLUSIONS

In children undergoing cardiac surgery with CPB, preoperative oral small-dose thyroid hormone therapy reduces severity of postoperative ESS and provides a protection against myocardial IRI by increasing HSP70 and MHCα expression.

Food Bioactive HDAC Inhibitors in the Epigenetic Regulation of Heart Failure

Approximately 5.7 million U.S. adults have been diagnosed with heart failure (HF). More concerning is that one in nine U.S. deaths included HF as a contributing cause. Current HF drugs (e.g., β-blockers, ACEi) target intracellular signaling cascades downstream of cell surface receptors to prevent cardiac pump dysfunction. However, these drugs fail to target other redundant intracellular signaling pathways and, therefore, limit drug efficacy. As such, it has been postulated that compounds designed to target shared downstream mediators of these signaling pathways would be more efficacious for the treatment of HF. Histone deacetylation has been linked as a key pathogenetic element for the development of HF. Lysine residues undergo diverse and reversible post-translational modifications that include acetylation and have historically been studied as epigenetic modifiers of histone tails within chromatin that provide an important mechanism for regulating gene expression. Of recent, bioactive compounds within our diet have been linked to the regulation of gene expression, in part, through regulation of the epi-genome. It has been reported that food bioactives regulate histone acetylation via direct regulation of writer (histone acetyl transferases, HATs) and eraser (histone deacetylases, HDACs) proteins. Therefore, bioactive food compounds offer unique therapeutic strategies as epigenetic modifiers of heart failure. This review will highlight food bio-actives as modifiers of histone deacetylase activity in the heart.

Effects of enteral different-dose levothyroxinesodium pretreatment on serum thyroid hormone levels and myocardial ischemia-reperfusion injury

INTRODUCTION

The available evidence shows that perioperative oral thyroid hormone can significantly attenuate the postoperative decline in the serum hormone level and improve postoperative hemodynamic and prognostic parameters. However, there has been no study assessing the effects of preoperative oral different-dose thyroid hormone on serum hormone levels and myocardial ischemia-reperfusion injury (IRI) after cardiac surgery.

METHODS

Forty-eight healthy Wistar rats, aged 35 days, were randomly allocated into six groups: Group BC, Group C and four pretreatment groups in which the rats were given levothyroxine-sodium of 10 μg, 20 μg, 40 μg and 80 μg/100 g. On the eighth day, the serum thyroid hormone levels were determined and then an isolated heart ischemia-reperfusion model was established with a Langendorff apparatus.

RESULTS

Compared with Groups BC and C, serum thyroid hormone levels on the eighth day did not significantly change in Group 10 μg, but were significantly increased in Groups 20 μg, 40 μg and 80 μg. The cardiac enzyme myocardial-bound creatine kinase levels in the coronary effluent during reperfusion were significantly lower in Groups 10 μg and 20 μg and 40 μg than in Group C. The recovery rates of + dp/dt_max and - dp/dt_max at 30 min during reperfusion were significantly lower in Groups 40 μg and 80 μg than in Groups 10 μg and 20 μg. Compared with Group C, myocardial expressions of heat shock protein 70 and myosin heavy chain α were increased in the four experiment groups and myocardial expression of thyroid hormone receptor α1 was significantly increased in Groups 20 μg, 40 μg and 80 μg.

CONCLUSIONS

The pretreatment with enterally smaller doses levothyroxine-sodium does not significantly affect serum thyroid hormone levels and produces protection against myocardial IRI, whereas pretreatment with enterally larger doses of levothyroxine-sodium can only provide an attenuated or insignificant cardioprotection because of hyperthyroxinemia. Cardioprotection by levothyroxine-sodium pretreatment is probably attributable to increased myocardial expression of heat shock protein 70 and myosin heavy chain α.

Interaction of risk factors, comorbidities, and comedications with ischemia/reperfusion injury and cardioprotection by preconditioning, postconditioning, and remote conditioning

Pre-, post-, and remote conditioning of the myocardium are well described adaptive responses that markedly enhance the ability of the heart to withstand a prolonged ischemia/reperfusion insult and provide therapeutic paradigms for cardioprotection. Nevertheless, more than 25 years after the discovery of ischemic preconditioning, we still do not have established cardioprotective drugs on the market. Most experimental studies on cardioprotection are still undertaken in animal models, in which ischemia/reperfusion is imposed in the absence of cardiovascular risk factors. However, ischemic heart disease in humans is a complex disorder caused by, or associated with, cardiovascular risk factors and comorbidities, including hypertension, hyperlipidemia, diabetes, insulin resistance, heart failure, altered coronary circulation, and aging. These risk factors induce fundamental alterations in cellular signaling cascades that affect the development of ischemia/reperfusion injury per se and responses to cardioprotective interventions. Moreover, some of the medications used to treat these risk factors, including statins, nitrates, and antidiabetic drugs, may impact cardioprotection by modifying cellular signaling. The aim of this article is to review the recent evidence that cardiovascular risk factors and their medication may modify the response to cardioprotective interventions. We emphasize the critical need to take into account the presence of cardiovascular risk factors and concomitant medications when designing preclinical studies for the identification and validation of cardioprotective drug targets and clinical studies. This will hopefully maximize the success rate of developing rational approaches to effective cardioprotective therapies for the majority of patients with multiple risk factors.

Neuroprotective role of Indirubin-3'-monoxime, a GSKβ inhibitor in high fat diet induced cognitive impairment in mice

Recent studies have highlighted that diabetes mellitus (DM) is a strong risk factor for Alzheimer's disease (AD). Insulin resistance and/or hyperinsulinemia is one of the main characteristics of type 2 DM. Numerous epidemiological studies have demonstrated that insulin resistance contributes to AD pathogenesis. However the molecular mechanisms of association between these still remain elusive. Among the various possible mechanisms, the GSK-3β activity has been reported to be impaired in insulin-resistance, type 2 DM and AD. Thus, the present study was designed to explore the neuroprotective role of GSK3 β inhibitor, Indirubin-3'-monoxime (IMX) in insulin resistance induced cognitive impairment. Further, we have explored the possible molecular mechanism involved in cognitive impairment associated with insulin resistance. The mice subjected to high fat diet exhibited characteristic features of insulin resistance viz. increased serum glucose, triglycerides, cholesterol, insulin levels and impaired spatial learning and memory ability along with reduced brain insulin level, elevated oxidative stress and acetylcholinesterase (AChE) activity. The observed changes occurred concurrently with reduced brain derived neurotrophic factor. In contrast, the mice treated with IMX showed a significant reduction in plasma glucose, triglycerides, cholesterol, insulin levels and improvement in learning and memory performance, attenuated the oxidative stress and AChE activity. Moreover, IMX dose dependently augment the brain insulin and BDNF levels in HFD fed mice. Based upon these findings it could be suggested that GSK3 β inhibition could prove to be beneficial in insulin resistance induced cognitive deficit and this neuroprotection could be the result of enhanced BDNF based synaptic plasticity.

Pharmacologic prophylactic treatment for perioperative protection of skeletal muscle from ischemia-reperfusion injury in reconstructive surgery

BACKGROUND

In autogenous muscle transplantation, unpredictable complications can cause prolonged ischemia, resulting in ischemia-reperfusion injury. The authors investigated the efficacy and mechanism of nicorandil, a nitrovasodilator and adenosine triphosphate-sensitive potassium channel opener, in inducing perioperative protection of muscle flaps from ischemia-reperfusion injury.

METHODS

Pigs (18.2 ± 2.4 kg) were assigned to one control and eight treatment groups. Bilateral latissimus dorsi muscle flaps were raised after saline administration (control) and 0, 4, 8, 12, 24, 48, 72, and 96 hours after nicorandil administration. Subsequently, flaps were subjected to 4 hours of ischemia and 48 hours of reperfusion. Viability was assessed, and biochemical probes were used to study nicorandil-induced infarct protection.

RESULTS

Protection by nicorandil was biphasic. Infarction reduced from 40.2 ± 1.9 percent (control) to 27.3 ± 1.7 percent and 24.0 ± 2.3 percent (p < 0.05) 0 and 4 hours after nicorandil administration, respectively (early phase protection). No difference was seen between control and treatment groups between 8 and 12 hours after nicorandil administration compared with the control. Infarct protection increased again (p < 0.05) at 24 (22.4 ± 2.0 percent), 48 (25.1 ± 2.1 percent), and 72 hours (28.5 ± 2.1 percent) but not at 96 hours (43.9 ± 4.6 percent) compared with control (late phase protection). The sarcolemmal and mitochondrial channels played a central role in the trigger and mediator mechanisms, respectively. Late protection was associated with lower myeloperoxidase activity and mitochondrial calcium overload and higher adenosine triphosphate content (p < 0.05).

CONCLUSIONS

Nicorandil induced 48-hour uninterrupted muscle infarct protection, starting 24 hours after intravenous administration. This category of clinical drug is a potential prophylactic treatment against skeletal muscle ischemia-reperfusion injury in reconstructive surgery.

Possible Strategies for the Diagnosis of Fatal Excited Delirium Syndrome

Excited Delirium Syndrome (ExDS) is a term traditionally used in forensic literature to describe the symptoms and signs seen in a subgroup of patients with delirium who die in an agitated state. Components of this syndrome are altered mental status, combativeness and/or aggressiveness, increased tolerance to significant pain, tachypnea, profuse sweating, severe agitation, elevated temperature, delirium, and noncompliance with law enforcement and medical personnel. The individual may display “superhuman” strength and wear clothing inappropriate for the environment. Patients with this presentation are almost guaranteed to cause difficulties for law enforcement officers and medical staff. This review is written in hopes of minimizing some of these difficulties by 1) increasing general awareness and specific knowledge about this condition, 2) explaining the neurochemical and neuroanatomical alterations that have been shown to cause those symptoms, and 3) by suggesting new lines of research that might identify easily measured biomarkers for the disease. If the disease mechanism can be deciphered, then it should be possible to devise effective strategies for treatment. It would also be of enormous value to the legal system. When defending a diagnosis before the court, physical evidence always trumps knowledge and experience. It would be far better to be able to present physical proof than to opine that the decedent's behavior was typical for the disease. In this aspect, ExDS is analogous to myocardial infarction: if a man dies suddenly, it is much easier to prove the cardiac origin of the event if an occlusive thrombus is found in a major coronary artery.