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Takotsubo Syndrome (TTS) is a potentially life-threatening disease characterized by a transient left ventricular apical akinesia in response to β-adrenergic overstimulation. Since a genetic predisposition is assumed, we generated an iPSC-line carrying a p.F189L mutation in the calcium buffering protein Calsequestrin 2 (CasQ2). This missense mutation was previously discovered in a TTS patient and further described in a family with Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT). The established cell line is used to investigate the main mechanisms leading to TTS and CPVT using a patient-specific stem cell approach., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Katrin Streckfuss-Boemeke reports a relationship with BioNtech that includes: funding grants. Katrin Streckfuss-Boemeke reports a relationship with Novartis that includes: speaking and lecture fees. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Background: Takotsubo Cardiomyopathy (TCM) is a transient heart condition often precipitated by stress and characterized by atypical ventricular ballooning. The interplay between TCM and Adrenal Insufficiency (AI), particularly the influence of catecholamine excess and glucocorticoid deficiency on TCM's pathogenesis in individuals with AI, warrants comprehensive exploration for a better understanding of TCM pathophysiology and establishment of potential therapeutic strategies., Methods: We conducted an extensive literature search via PubMed and Google Scholar, targeting reports on AI, heart failure, and cardiomyopathy, supplemented by forward and backward citation tracing. We analyzed 46 cases from 45 reports, assessing the clinical presentation and outcomes in the context of AI categorization., Results: In patients with AI, a glucocorticoid deficit appears to exacerbate the myocardial vulnerability to catecholamine toxicity, precipitating TCM. Most conditions were reversible; however, three pre-1990 cases resulted in irreversible outcomes., Conclusions: The investigation into the AI and TCM intersection highlights the pathogenic significance of catecholamines in the absence of glucocorticoids. The data consolidates the hypothesis that glucocorticoid scarcity exacerbates the cardiac susceptibility to catecholaminergic toxicity, potentially triggering TCM. The study affirms glucocorticoids' cardioprotective roles and elucidates how catecholamine surges contribute to TCM pathogenesis, suggesting strategic clinical management adjustments for AI patients to reduce TCM incidence., Competing Interests: Declaration of competing interest None., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: ST-elevation myocardial infarction (STEMI) and Takotsubo syndrome (TS) are two distinct cardiac conditions that both result in sudden loss of cardiac dysfunction and that are difficult to distinguish clinically. This study compared plasma protein changes in 24 women with STEMI and 12 women with TS in the acute phase (days 0-3 post symptom onset) and the stabilization phase (days 7, 14, and 30) to examine the molecular differences between these conditions., Methods: Plasma proteins from STEMI and TS patients were extracted during the acute and stabilization phases and analyzed via quantitative proteomics. Differential expression and functional significance were assessed. Data are accessible on ProteomeXchange, ID PXD051367., Results: During the acute phase, STEMI patients showed higher levels of myocardial inflammation and tissue damage proteins compared to TS patients, along with reduced tissue repair and anti-inflammatory proteins. In the stabilization phase, STEMI patients exhibited ongoing inflammation and disrupted lipid metabolism. Notably, ADIPOQ was consistently downregulated in STEMI patients in both phases. When comparing the acute to the stabilization phase, STEMI patients showed increased inflammatory proteins and decreased structural proteins. Conversely, TS patients showed increased proteins involved in inflammation and the regulatory response to counter excessive inflammation. Consistent protein changes between the acute and stabilization phases in both conditions, such as SAA2, CRP, SAA1, LBP, FGL1, AGT, MAN1A1, APOA4, COMP, and PCOLCE, suggest shared underlying pathophysiological mechanisms., Conclusions: This study presents protein changes in women with STEMI or TS and identifies ADIPOQ, SAA2, CRP, SAA1, LBP, FGL1, AGT, MAN1A1, APOA4, COMP, and PCOLCE as candidates for further exploration in both therapeutic and diagnostic contexts.

Competing Interests: Declaration of competing interest None.

Introduction: The pathophysiology of Takotsubo syndrome (TTS) is not completely understood and the role of chronic stress is among the main mechanistic links. The aim of this study was to explore whether accumulating hair cortisol concentration (HCC), a novel biomarker of chronic stress, is associated with the occurrence of TTS., Methods: A consecutive series of 18 TTS patients and 36 age and sex matched healthy controls were included in our analysis. Hair samples were collected from participants'' vertex. The proximal 2.5 cm of hair was cut in equal parts of 0.5 cm, reflecting mean cortisol levels in time intervals of 0-15, 15-30, 30-45, 45-60 and 60-75 days prior to hair collection., Results: HCC was higher in TTS group compared to controls at any time point and increased over time starting from 75 days prior to the event. The rate of HCC increase was significantly higher in TTS patients versus controls (beta of interaction = 0.48; 95%CI: 0.36-0.60; p < 0.001)., Conclusions: The steadily increasing trend of HCC in TTS patients suggests that the additive effect of multiple stressful events over several weeks prior TTS onset may disrupt cortisol homeostasis and play a role in TTS pathophysiology., Competing Interests: Declaration of competing interest The authors report there are no competing interests to declare., (Copyright © 2023. Published by Elsevier B.V.)

Takotsubo syndrome (TTS) is a particular form of acute heart failure that can be challenging to distinguish from acute coronary syndrome at presentation. TTS was previously considered a benign self-limiting condition, but it is now known to be associated with substantial short- and long-term morbidity and mortality. Because of the poor understanding of its underlying pathophysiology, there are few evidence-based interventions to treat TTS. The hypotheses formulated so far can be grouped into endogenous adrenergic surge, psychological stress or preexisting psychiatric illness, coronary vasospasm with microvascular dysfunction, metabolic and energetic alterations, and inflammatory mechanisms. Current evidence demonstrates that the infiltration of immune cells such as macrophages and neutrophils play a pivotal role in TTS. At baseline, resident macrophages were the dominant subset in cardiac macrophages, however, it underwent a shift from resident macrophages to monocyte-derived infiltrating macrophages in TTS. Depletion of macrophages and monocytes in mice strongly protected them from isoprenaline-induced cardiac dysfunction. It is probable that immune cells, especially macrophages, may be new targets for the treatment of TTS., (© 2024 The Author(s). Journal of Cellular and Molecular Medicine published by Foundation for Cellular and Molecular Medicine and John Wiley & Sons Ltd.)

In acute sympathetic stress, catecholamine overload can lead to stress cardiomyopathy. We tested the hypothesis that cardiomyocyte NOX4 (NADPH oxidase 4)-dependent mitochondrial oxidative stress mediates inflammation and diastolic dysfunction in stress cardiomyopathy. Isoproterenol (ISO; 5 mg/kg) injection induced sympathetic stress in wild-type and cardiomyocyte (CM)-specific Nox4 knockout (Nox4 CM-/- ) mice. Wild-type mice treated with ISO showed higher CM NOX4 expression, H 2 O 2 levels, inflammasome activation, and IL18, IL6, CCL2, and TNFα levels than Nox4 CM-/- mice. Spectral flow cytometry and t-SNE analysis of cardiac cell suspensions showed significant increases in pro-inflammatory and pro-fibrotic embryonic-derived resident (CCR2 - MHCII hi CX3CR1 hi ) macrophages in wild-type mice 3 days after ISO treatment, whereas Nox4 CM-/- mice had a higher proportion of embryonic-derived resident tissue-repair (CCR2 - MHCII lo CX3CR1 lo ) macrophages. A significant increase in cardiac fibroblast activation and interstitial collagen deposition and a restrictive pattern of diastolic dysfunction with increased filling pressure was observed in wild-type hearts compared with Nox4 CM-/- 7 days post-ISO. A selective NOX4 inhibitor, GKT137831, reduced myocardial mitochondrial ROS, macrophage infiltration, and fibrosis in ISO-injected wild-type mice, and preserved diastolic function. Our data suggest sympathetic overstimulation induces resident macrophage (CCR2 - MHCII + ) activation and myocardial inflammation, resulting in fibrosis and impaired diastolic function mediated by CM NOX4-dependent ROS., Competing Interests: Declaration of competing interest Marschall S. Runge is a member of the Board of Directors at Eli Lilly and Company. Other authors have declared that no conflict of interest exists., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

Takotsubo syndrome (TTS) is an acute heart failure syndrome that mimics the symptoms of acute myocardial infarction and is often preceded by emotional and/or physical stress. There is currently no treatment for TTS. Here we show that injection of 2.5 mg kg -1 of epinephrine (EPI) into mice recapitulates numerous features of human TTS, including increased myocardial damage and mortality in males. Gene set enrichment analysis of myocardial RNA sequencing after EPI injection revealed significant enrichment of calcineurin-dependent pro-inflammatory gene networks, which was more pronounced in male than in female mice, in agreement with observed sex discrepancies in the mouse phenotype. An increase in calcineurin activity was detected in the circulating cells of patients with TTS, suggesting a systemic nature of the syndrome. Preventive and therapeutic treatment of mice injected with EPI using calcineurin inhibitors cyclosporine and tacrolimus improved heart function and reduced myocardial injury. Our findings suggest that calcineurin inhibition could be a potential therapy for TTS., (© 2023. The Author(s).)

Takotsubo cardiomyopathy is a stress-induced cardiovascular disease with symptoms comparable to those of an acute coronary syndrome but without coronary obstruction. Takotsubo was initially considered spontaneously reversible, but epidemiological studies revealed significant long-term morbidity and mortality, the reason for which is unknown. Here, we show in a female rodent model that a single pharmacological challenge creates a stress-induced cardiomyopathy similar to Takotsubo. The acute response involves changes in blood and tissue biomarkers and in cardiac in vivo imaging acquired with ultrasound, magnetic resonance and positron emission tomography. Longitudinal follow up using in vivo imaging, histochemistry, protein and proteomics analyses evidences a continued metabolic reprogramming of the heart towards metabolic malfunction, eventually leading to irreversible damage in cardiac function and structure. The results combat the supposed reversibility of Takotsubo, point to dysregulation of glucose metabolic pathways as a main cause of long-term cardiac disease and support early therapeutic management of Takotsubo., (© 2023. The Author(s).)

Intracranial hemorrhage results in devastating forms of cerebral damage. Frequently, these results also present with cardiac dysfunction ranging from ECG changes to Takotsubo syndrome (TTS). This suggests that intracranial bleeding due to subarachnoid hemorrhage (SAH) disrupts the neuro-cardiac axis leading to neurogenic stress cardiomyopathy (NSC) of different degrees. Following this notion, SAH and secondary TTS could be directly linked, thus contributing to poor outcomes. We set out to test if blood circulation is the driver of the brain-heart axis by investigating serum samples of TTS patients. We present a novel in vitro model combining SAH and secondary TTS to mimic the effects of blood or serum, respectively, on blood-brain barrier (BBB) integrity using in vitro monolayers of an established murine model. We consistently demonstrated decreased monolayer integrity and confirmed reduced Claudin-5 and Occludin levels by RT-qPCR and Western blot and morphological reorganization of actin filaments in endothelial cells. Both tight junction proteins show a time-dependent reduction. Our findings highlight a faster and more prominent disintegration of BBB in the presence of TTS and support the importance of the bloodstream as a causal link between intracerebral bleeding and cardiac dysfunction. This may represent potential targets for future therapeutic inventions in SAH and TTS.

Aims: Cardiac energetic impairment is a major finding in takotsubo patients. We investigate specific metabolic adaptations to direct future therapies., Methods and Results: An isoprenaline-injection female rat model (vs. sham) was studied at Day 3; recovery assessed at Day 7. Substrate uptake, metabolism, inflammation, and remodelling were investigated by 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography, metabolomics, quantitative PCR, and western blot (WB). Isolated cardiomyocytes were patch-clamped during stress protocols for redox states of NAD(P)H/FAD or [Ca2+]c, [Ca2+]m, and sarcomere length. Mitochondrial respiration was assessed by seahorse/Clark electrode (glycolytic and β-oxidation substrates). Cardiac 18F-FDG metabolic rate was increased in takotsubo (P = 0.006), as was the expression of GLUT4-RNA/GLUT1/HK2-RNA and HK activity (all P < 0.05), with concomitant accumulation of glucose- and fructose-6-phosphates (P > 0.0001). Both lactate and pyruvate were lower (P < 0.05) despite increases in LDH-RNA and PDH (P < 0.05 both). β-Oxidation enzymes CPT1b-RNA and 3-ketoacyl-CoA thiolase were increased (P < 0.01) but malonyl-CoA (CPT-1 regulator) was upregulated (P = 0.01) with decreased fatty acids and acyl-carnitines levels (P = 0.0001-0.02). Krebs cycle intermediates α-ketoglutarate and succinyl-carnitine were reduced (P < 0.05) as was cellular ATP reporter dihydroorotate (P = 0.003). Mitochondrial Ca2+ uptake during high workload was impaired on Day 3 (P < 0.0001), inducing the oxidation of NAD(P)H and FAD (P = 0.03) but resolved by Day 7. There were no differences in mitochondrial respiratory function, sarcomere shortening, or [Ca2+] transients of isolated cardiomyocytes, implying preserved integrity of both mitochondria and cardiomyocyte. Inflammation and remodelling were upregulated-increased CD68-RNA, collagen RNA/protein, and skeletal actin RNA (all P < 0.05)., Conclusion: Dysregulation of glucose and lipid metabolic pathways with decreases in final glycolytic and β-oxidation metabolites and reduced availability of Krebs intermediates characterizes takotsubo myocardium. The energetic deficit accompanies defective Ca2+ handling, inflammation, and upregulation of remodelling pathways, with the preservation of sarcomeric and mitochondrial integrity., (© The Author(s) 2021. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Takotsubo syndrome (TTS) is identified as an acute severe ventricular systolic dysfunction, which is usually characterized by reversible and transient akinesia of walls of the ventricle in the absence of a significant obstructive coronary artery disease (CAD). Patients present with chest pain, ST-segment elevation or ischemia signs on ECG and increased troponin, similar to myocardial infarction. Currently, the known mechanisms associated with the development of TTS include elevated levels of circulating plasma catecholamines and their metabolites, coronary microvascular dysfunction, sympathetic hyperexcitability, inflammation, estrogen deficiency, spasm of the epicardial coronary vessels, genetic predisposition and thyroidal dysfunction. However, the real etiologic link remains unclear and seems to be multifactorial. Currently, the elusive pathogenesis of TTS and the lack of optimal treatment leads to the necessity of the application of experimental models or platforms for studying TTS. Excessive catecholamines can cause weakened ventricular wall motion at the apex and increased basal motion due to the apicobasal adrenoceptor gradient. The use of beta-blockers does not seem to impact the outcome of TTS patients, suggesting that signaling other than the beta-adrenoceptor-associated pathway is also involved and that the pathogenesis may be more complex than it was expected. Herein, we review the pathophysiological mechanisms related to TTS; preclinical TTS models and platforms such as animal models, human-induced pluripotent stem cell-derived cardiomyocyte (hiPSC-CM) models and their usefulness for TTS studies, including exploring and improving the understanding of the pathomechanism of the disease. This might be helpful to provide novel insights on the exact pathophysiological mechanisms and may offer more information for experimental and clinical research on TTS.

Cerebrovascular diseases such as ischemic stroke, brain hemorrhage, and subarachnoid hemorrhage provoke cardiac complications such as heart failure, neurogenic stress-related cardiomyopathy and Takotsubo cardiomyopathy. With regards to the pathophysiology of stroke-induced heart injury, several mechanisms have been postulated to contribute to this complex interaction between brain and heart, including damage from gut dysbiosis, immune and systematic inflammatory responses, microvesicle- and microRNA-mediated vascular injury and damage from a surge of catecholamines. All these cerebrovascular diseases may trigger pronounced catecholamine surges through diverse ways, including stimulation of hypothalamic-pituitary adrenal axis, dysregulation of autonomic system, and secretion of adrenocorticotropic hormone. Primary catecholamines involved in this pathophysiological response include norepinephrine (NE) and epinephrine. Both are important neurotransmitters that connect the nervous system with the heart, leading to cardiac damage via myocardial ischemia, calcium (Ca 2+ ) overload, oxidative stress, and mitochondrial dysfunction. In this review, we will aim to summarize the molecular mechanisms behind catecholamine-induced cardiotoxicity including Ca 2+ overload, oxidative stress, apoptosis, cardiac hypertrophy, interstitial fibrosis, and inflammation. In addition, we will focus on how synchronization among these pathways evokes cardiotoxicity., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Takotsubo cardiomyopathy (TTC), a persistently obscure dysfunctional condition of the left ventricle, is uniquely transient but nevertheless dangerous. It features variable ventricular patterns and is predominant in women. For 30 years, pathophysiologic investigations have progressed only slowly and with inadequate focus. It was initially proposed that sudden-onset spastic obliteration of coronary flow induced myocardial ischemia with residual stunning and thus TTC. Later, it was generally accepted without proof that, in the presence of pain or emotional stress, the dominant mechanism for TTC onset was a catecholamine surge that had a direct, toxic myocardial effect. We think that the manifestations of TTC are more dynamic and complex than can be assumed from catecholamine effects alone. In addition, after reviewing the recent medical literature and considering our own clinical observations, especially on spasm, we theorize that atherosclerotic coronary artery disease modulates and physically opposes obstruction during spasm. This phenomenon may explain the midventricular variant of TTC and the lower incidence of TTC in men. We continue to recommend and perform acetylcholine testing to reproduce TTC and to confirm our theory that coronary spasm is its initial pathophysiologic factor. An improved understanding of TTC is especially important because of the condition's markedly increased incidence during the ongoing COVID-19 pandemic., (© 2021 by the Texas Heart® Institute, Houston.)

Stress cardiomyopathy (SC) is an increasingly recognized form of acute heart failure, which has been linked to a wide variety of emotional and physical triggers. The pathophysiological mechanisms of the disease remain incompletely understood, however, inflammation has been recently shown to play a pivotal role. This review summarizes the most notable findings of myocardial inflammation, demonstrated from biopsies and cardiac magnetic resonance imaging in humans. In the acute stage macrophage infiltration appears to represent the substrate for myocardial edema, together defining the local myocardial inflammation. This appears to evolve into a low grade systemic chronic inflammation which could explain the protracted clinical course of these patients and raises hope for finding a specific SC cardiac biomarker as well as a therapeutic breakthrough. As a parallel to the human findings the review covers some of the emerging mechanistic insights from experimental models, which, albeit not proven in the human condition, highlight the possible importance in pursuing distinct paths of investigation such as the beta-receptor signaling, aberrations of nitric oxide generation and signaling and the contribution of the vascular endothelium/permeability to edema and inflammation during the acute stage., (Copyright © 2020. Published by Elsevier Inc.)

Background: Takotsubo (TTS) syndrome is an acute cardiac condition characterized by transient and reversible left ventricle dysfunction that mainly affects postmenopausal women. Catecholamine burst is the most accredited mechanism underpinning TTS onset and leading to endothelial dysfunction and platelet activation. Even if the use of low dose acetylsalycilic acid (ASA) in this clinical setting is based on both clinical presentation and unfavorable long-term prognosis, its efficacy has been recently challenged., Aim: This study was designed to assess endothelial function, residual thromboxane formation and platelet aggregation in TTS women on low-dose ASA treatment at long-term follow-up., Methods: Twenty-eight females with previously diagnosis of TTS syndrome were enrolled. Data were compared to those obtained from 23 coronary artery disease (CAD) women with a history of acute myocardial infarction, and 26 control subjects with no TTS or clinically evident CAD. Psychological and clinical profile were assessed in all study groups at the enrollment. Main metabolites involved in L-arginine/nitric oxide pathway, urinary prostacyclin, serum and urine thromboxane metabolites were measured by LCMS/MS methods. Thrombomodulin levels were quantified using an ELISA kit, and platelet aggregation, carried out on platelet rich-plasma, was induced by ADP or by epinephrine (EPI), norepinephrine (NORE) and TRAP-6, alone or in association with ADP and evaluated by Born's method., Results: In TTS women an endothelial derangement, characterized by reduced citrulline production and increased thrombomodulin concentration, with no perturbation in prostacyclin levels, was evidenced. In addition, despite ASA treatment, TTS displayed a higher residual thromboxane formation, in parallel with an enhanced platelet response to compared to CAD., Conclusions: Our study highlighted the presence of endothelial perturbation in TTS patients even at long-term from the index event. The residual thromboxane production and platelet aggregation still leave open the question about the use of low dose ASA in this clinical setting., (Copyright © 2021 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Innumerable physical stress factors including externally administered catecholamines, and pheochromocytomas and paragangliomas (PPGLs) have been reported to trigger Takotsubo syndrome (TS). A systematic search of PubMed/MEDLINE identified 156 patients with catecholamine-induced TS up to December 2017. Data were compared within the catecholamine-induced TS cohort, but some comparisons were also done to a previously published large all-TS cohort (n = 1750). The mean age was 46.4 ± 16.4 years (72.3% women). The clinical presentation was dramatic with high complication rates in (68.2%, n = 103; multiple complications 34.6%, n = 54). The most common TS ballooning pattern was apical or mid-apical (45.2%, n = 69), followed by basal pattern (28.8%, n = 45), global pattern (16.0%, n = 25), mid-ventricular (8.3%, n = 13), focal (0.6%, n = 1), and unidentified pattern (1.9%, n = 3). There was an increase in the prevalence of apical sparing ballooning pattern compared to all-TS population (37.7% vs 18.3%, P < .00001). Higher complication rates were observed in TS with global ballooning pattern compared to apical ballooning pattern (23/25, 92% vs 38/65, 58.5%; P = .0022). Higher complication rates were observed in patients with age < 50 years than patients >50 years (73/92, 79.3% vs 29/56, 51.8%, P = 0.0009). Recurrence occurred exclusively in patients with PPGL-induced TS (18/107 patients, 16.8%). PPGL-induced TS was characterized by more global ballooning's pattern (22/104, 21.2% vs 3/49, 6.1%, P = 0.02), and lower left ventricular ejection fraction (25.54 ± 11.3 vs 31.82 ± 9.93, P = 0.0072) compared to exogenous catecholamine-induced TS. In conclusion, catecholamine-induced TS was characterized by a dramatic clinical presentation with extensive left ventricular dysfunction, and high complication rate., (© 2020 The Authors. Clinical Cardiology published by Wiley Periodicals, Inc.)

Introduction: Takotsubo syndrome (TTS) is a stress-induced cardiomyopathy, but the accurate cause of this syndrome is still unknown., Methods: β-adrenergic agonist isoproterenol (ISO) is used to establish the TTS rats model. TTS rats were treated with or without LY294002 or Rapamycin. The rat cardiomyoblast cell line H9C2 was subjected to infect with constitutively active Akt (myr-Akt) or dominant-negative mutant Akt (dn-Akt) and then, treated with ISO. Cell apoptosis was assessed using the Bax/ Bcl-2 ratio. In addition, reactive oxygen species (ROS) levels were measured using dihydroethidium (DHE). Mitochondrial superoxide generation and membrane potential were assayed by MitoSOX and JC-1 fluorescence intensity., Results: ISO might induce the erratic acute cardiac dysfunction and overexpression of PI3K/AKT/mTOR. Moreover, it also increased the oxidative stress and apoptosis in TTS rats. The Akt inhibitor significantly reversed the cardiac injury effect, which triggered by ISO treatment. In H9C2 cells, the inhibition of Akt provides a protective role against ISO-induced injury by reducing oxidative stress, apoptosis and mitochondrial dysfunction., Conclusion: This study provided new insight into the protective effects of myocardial dysfunction in TTS rats via chronic inhibition of the PI3K/AKT/mTOR expression, which could reduce mitochondrial ROS and oxidative stress-induced apoptosis. PI3K/AKT/mTOR inhibitor could be a therapeutic target to treat cardiovascular dysfunction induced by stress cardiomyopathy., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Purpose of Review: Recently, an association between cannabis use and Takotsubo (stress) cardiomyopathy (TTC) has been shown. With the current trend of legalization of cannabis, it is important to understand brain effects of cannabis use that could lead to cardiac disease, such as TTC. Here we review recent brain imaging studies in order to search for the evidence supporting the association between cannabis use, stress, and TTC., Recent Findings: There exist brain imaging studies showing similar findings across TTC, stress, and cannabis use. These similar findings are mainly centered on a key central autonomic network region amygdala, i.e., amygdala hyperactivity/hyperconnectivity when exposed to challenge, stress, or negative stimuli. This similarity supports a close association among cannabis use, stress, and TTC. Amygdala-centered neuronal circuits could underlie cannabis use as risk factor to TTC. Based on the findings, several directions for future studies are proposed.

Background: An association between Tako-Tsubo cardiomyopathy (TTC) and underlying malignancies has been observed, suggesting that TTC might be the consequence of paraneoplastic phenomena. This study investigates the presence of autoantibodies against cardiomyocytes as well as adrenergic (β 1 , β 2 ) and muscarinic (M2) receptors in patients with TTC., Methods and Results: Serum from 20 TTC patients and 20 controls with ischemic heart disease was obtained. Indirect immunofluorescence testing for intracellular autoantibodies against cardiomyocytes showed a homogenous distribution, as in both groups 9 of 20 sera displayed a characteristic binding pattern of antibodies including vascular walls and intracellular structures. Flow cytometry analysis revealed no difference between TTC and controls in the binding of autoantibodies to the surface antigens of cardiomyocyte HL-1 cells (p = 0.569, t-test). Flow cytometry analysis of nontransfected wild type cells (p = 0.633, t-test), M2 receptor-transfected cells (p = 0.687, t-test), β 1 receptor-transfected cells (p = 0.444, t-test) and β 2 receptor-transfected cells (p = 0.632, t-test) showed similar results for control and TTC sera. Likewise, the binding pattern of TTC patients with a history of neoplasia compared to those without or to controls did not differ significantly (p > 0.05, u-test)., Conclusion: Findings suggest that the presumed paraneoplastic etiology of TTC cannot be attributed to the formation of these antibodies., (Copyright © 2018. Published by Elsevier GmbH.)

Activation of neutrophils is a critically important component of the innate immune response to bacterial and chemical stimuli, and culminates in the "neutrophil burst", which facilitates neutrophil phagocytosis via the release of superoxide anion radical (O₂ - ) from NADPH oxidase. Excessive and/or prolonged neutrophil activation results in substantial tissue injury and increases in vascular permeability-resulting in sustained tissue infiltration with neutrophils and monocytes, and persistent vasomotor dysfunction. Cardiovascular examples of such changes include acute and chronic systolic and diastolic heart failure ("heart failure with preserved ejection fraction"), and the catecholamine-induced inflammatory disorder takotsubo syndrome. We have recently demonstrated that B-type natriuretic peptide (BNP), acting via inhibition of activation of neutrophil NADPH oxidase, is an important negative modulator of the "neutrophil burst", though its effectiveness in limiting tissue injury is partially lost in acute heart failure. The potential therapeutic implications of these findings, regarding the development of new means of treating both acute and chronic cardiac injury states, are discussed.

Myocardial damage in catecholamine cardiomyopathy, characterized by patchy myocyte necrosis commonly with contraction band appearances, interstitial fibrosis, and varying degrees of inflammatory infiltrates, has been well documented. However, coronary vascular pathology has not been recognized. Autopsy of a 43-year-old housewife who died of acute apical anteroseptal myocardial infarction revealed the incidental finding of a left adrenal pheochromocytoma. The epicardial and intramyocardial median- and small-sized coronary arteries exhibited myointimal dysplasia in the form of fibroblastic proliferation in the intima and media, resulting in thickened dysplastic vessels with marked luminal narrowing, occasionally leading to near-total occlusion. The distal left anterior descending artery showed features of recanalization after prior embolic occlusion. The density and severity of vascular involvement revealed a decreasing gradient from apical to basal region, mainly affecting the left ventricle, but the proximal coronary arteries were minimally affected. Myointimal dysplasia was not seen in control cases of hypertensive heart, and despite its presence in hearts with hypertrophic cardiomyopathy, it lacked the distinctive pattern of distribution and the epicardial vessels are uninvolved. Myointimal dysplasia probably results from reactive fibroplasia in response to the vasoconstrictive effect of circulating or local neurosecretory catecholamine and appears crucial in the pathogenesis of various types of catecholamine cardiomyopathy, including Takotsubo or stress cardiomyopathy. Together with the direct catecholamine cardiotoxicity, they result in diffuse microscopic ischemic necrosis and fibrosis. Depending on the type of catecholamine overproduction and action, together with the characteristic anatomic distribution and density of the various types of adrenergic receptors in the ventricles, different regions of the heart are variously affected so that different patterns of ventricular dysfunction are produced, with the subsequent angiographic appearances ranging from apical through midventricular to basal ballooning. Additional complications from the myointimal dysplasia include spontaneous coronary dissection, acute myocardial infarction, and superimposed thrombus formation in the dysplastic vessels and dyskinetic ventricle, with the risk of further damage from embolic events., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Accumulating evidence indicates alteration of the β-adrenoceptor (AR), such as desensitization and subtype switching of its coupling G protein, plays a role in the protection against catecholamine toxicity in heart failure. However, in human takotsubo syndrome (TTS), which is associated with a surge of circulating catecholamine in the acute phase, there is no histologic evidence of β-AR alteration. The purpose of this study was to investigate the involvement of alteration of β-AR signaling in the mechanism of TTS development. Left ventricular (LV) biopsied samples from 26 patients with TTS, 19 with normal LV function, and 26 with dilated cardiomyopathy (DCM) were studied. G protein-coupled receptor kinase 2 (GRK2) and β-arrestin2, which initiate the alteration of β-AR signaling, were more abundantly expressed in the myocardium in acute-phase TTS than in those of DCM and normal control as indicated by immunohistochemistry. The percentage of cardiomyocytes that showed positive membrane staining for GRK2 and β-arrestin2 was also significantly higher in acute-phase TTS. Sequential biopsies in the recovery-phase for two patients with TTS revealed that membrane expression of GRK2 and β-arrestin2 faded over time. This study provided the first histologic evidence of the involvement of alteration of β-ARs in the development of TTS.

Takotsubo syndrome (TTS) is a poorly recognized heart disease that was initially regarded as a benign condition. Recently, it has been shown that TTS may be associated with severe clinical complications including death and that its prevalence is probably underestimated. Since current guidelines on TTS are lacking, it appears timely and important to provide an expert consensus statement on TTS. The clinical expert consensus document part I summarizes the current state of knowledge on clinical presentation and characteristics of TTS and agrees on controversies surrounding TTS such as nomenclature, different TTS types, role of coronary artery disease, and etiology. This consensus also proposes new diagnostic criteria based on current knowledge to improve diagnostic accuracy.

Aims: Toll-like receptors (TLR) and apoptosis were indicated as important factors in heart failure. Our aim was to characterize the morphological pattern of apoptosis, TLR2, TLR4, and TLR6 expression in female rat hearts in the model of takotsubo syndrome (TTS)., Main Methods: 60 Sprague-Dawley female rats were treated with a single dose of 150 mg/kg b.wt. of isoprenaline (ISO) or 0.9% NaCl (controls). Hearts were collected 24, 48, 72 h and 7 days post-ISO injection. 32/60 hearts were used in immunohistopathological studies and 28/60 in real time., Key Findings: Apoptosis was observed 24 h post-ISO in cardiomyocytes, 24, 48, 72 h and 7 days post-ISO in infiltrating inflammatory cells, 7 days post-ISO in endothelial cells of vessels. Diffuse TLR4CD68 (CD68, a macrophage marker) and TLR6CD68 positive cells and TLR2, TLR4, TLR6 mononuclear cells were observed in both acute and recovery phase of TTS. In the foci located in the neighborhood of damaged (necrotic/apoptotic) cardiomyocytes in TTS, high (strong) protein expression of TLR2 (TLR2 high ) was observed: 24, 48, 72 h post-ISO; TLR4 high - 48 and 72 h post-ISO; TLR6 high - 48 h post-ISO. Whereas in cardiomyocytes of remote myocardium: TLR2 high - 72 h post-ISO; TLR4 high - 24 and 72 h post-ISO; TLR6 high - 24 h post-ISO. TLR2 mRNA was down-regulated 48 and 72 h post-ISO whereas TLR4 up-regulated 7 days post-ISO., Significance: The expression pattern of apoptosis and TLR differs in the course of TTS in comparison with the control rats. We hypothesize that innate immunity and apoptosis may play a crucial role in TTS pathophysiology., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Takotsubo cardiomyopathy (TTC) is characterized by transient systolic ventricular dysfunction. It is supposed to be caused by a cathecolaminergic wave which leads to myocardial stunning through a massive action on beta2-adrenoreceptor. Moreover, beta2-receptor hyperactivity negatively influences endothelial function. It can be detected by brachial flow mediated dilation (b-FMD) which assesses endothelium regulated vasomotility. The study aim is to analyze the b-FMD variability during hospitalization in 50 patients admitted with TTC. In addition, we investigated a possible correlation between b-FMD at admission and both length of hospital stay (LOHS) and troponin I peak. We detected b-FMD by measuring the hypoxic induced vasoreactivity through assessing brachial artery dilation after 5 min of iatrogenic ischemia obtained by inflating a sphygmomanometer cuff. Artery diameter modifications were assessed by high-resolution ultrasound, and a dedicated software calculated accurately the percentage of dilation after ischemia by comparing it to the basal. These values were measured at admission and on discharge. The obtained values were compared for each patient to explore their variability during hospitalization. Moreover, the correlation between the b-FMD at admission and both the troponin I peak and the LOHS was investigated. There was a statistical significant difference between mean FMD measured at admission and at discharge (respectively 1.54 ± 0.34 and 8.92 ± 2.48%; p < 0.001). Moreover, we found a significant negative correlation between troponin I peak and FMD values at admission (r = - 0.7645; p < 0.001) and a significant inverse correlation between FMD at admission and LOHS (r = - 0.7543; p < 0.001). There is a significant improvement of b-FMD during hospitalization in patients admitted for Tako-Tsubo Cardiomyopathy. Moreover, for the first time, a direct correlation among b-FMD, troponin I peak and LOHS has been detected.

L-Homoarginine (hArg) and guanidinoacetate (GAA) are produced from L-arginine (Arg) by the catalytic action of arginine:glycine amidinotransferase. Guanidinoacetate methyltransferase methylates GAA on its non-guanidine N atom to produce creatine. Arg and hArg are converted by nitric oxide synthase (NOS) to nitric oxide (NO). NO is oxidized to nitrite and nitrate which circulate in the blood and are excreted in the urine. Asymmetric dimethylarginine (ADMA), an NOS inhibitor, is widely accepted to be exclusively produced after asymmetric N G -methylation of Arg residues in proteins and their regular proteolysis. Low circulating and urinary hArg concentrations and high circulating concentrations of ADMA emerged as risk markers in the human renal and cardiovascular systems. While ADMA's distribution and metabolism are thoroughly investigated, such studies on hArg are sparse. The aim of the present pilot study was to investigate the distribution of exogenous hArg in plasma, liver, kidney, lung, and heart in a rat model of takotsubo cardiomyopathy (TTC). hArg hydrochloride solutions in physiological saline were injected intra-peritoneally at potentially pharmacological, non-toxic doses of 20, 220, or 440 mg/kg body weight. Vehicle (saline) served as control. As hArg has been reported to be a pro-oxidant, plasma and tissue malondialdehyde (MDA) was measured as a biomarker of lipid peroxidation. hArg administration resulted in dose-dependent maximum plasma hArg concentrations and distribution in all investigated organs. hArg disappeared from plasma with an elimination half-life ranging between 20 and 40 min. hArg administration resulted in relatively small changes in the plasma and tissue content of Arg, GAA, ADMA, creatinine, and of the NO metabolites nitrite and nitrate. Remarkable changes were observed for tissue GAA, notably in the kidney. Plasma and tissue MDA concentration did not change upon hArg administration, suggesting that even high-dosed hArg is not an oxidant. The lowest hArg dose of 20 mg/kg bodyweight increased 25-fold the mean hArg maximum plasma concentration. This hArg dose seems to be useful as the upper limit in forthcoming studies on the putative cardioprotective effects of hArg in our rat model of TTC.

Background: Takotsubo syndrome (TTS) is characterized by an acute left ventricular dysfunction and is associated with life-threating complications in the acute phase. The underlying disease mechanism in TTS is still unknown. A genetic basis has been suggested to be involved in the pathogenesis., Objectives: The aims of the study were to establish an in vitro induced pluripotent stem cell (iPSC) model of TTS, to test the hypothesis of altered β-adrenergic signaling in TTS iPSC-cardiomyocytes (CMs), and to explore whether genetic susceptibility underlies the pathophysiology of TTS., Methods: Somatic cells of patients with TTS and control subjects were reprogrammed to iPSCs and differentiated into CMs. Three-month-old CMs were subjected to catecholamine stimulation to simulate neurohumoral overstimulation. We investigated β-adrenergic signaling and TTS cardiomyocyte function., Results: Enhanced β-adrenergic signaling in TTS-iPSC-CMs under catecholamine-induced stress increased expression of the cardiac stress marker NR4A1; cyclic adenosine monophosphate levels; and cyclic adenosine monophosphate-dependent protein kinase A-mediated hyperphosphorylation of RYR2-S2808, PLN-S16, TNI-S23/24, and Cav1.2-S1928, and leads to a reduced calcium time to transient 50% decay. These cellular catecholamine-dependent responses were mainly mediated by β 1 -adrenoceptor signaling in TTS. Engineered heart muscles from TTS-iPSC-CMs showed an impaired force of contraction and a higher sensitivity to isoprenaline-stimulated inotropy compared with control subjects. In addition, altered electrical activity and increased lipid accumulation were detected in catecholamine-treated TTS-iPSC-CMs, and were confirmed by differentially expressed lipid transporters CD36 and CPT1C. Furthermore, we uncovered genetic variants in different key regulators of cardiac function., Conclusions: Enhanced β-adrenergic signaling and higher sensitivity to catecholamine-induced toxicity were identified as mechanisms associated with the TTS phenotype. (International Takotsubo Registry [InterTAK Registry] [InterTAK]; NCT01947621)., (Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.)

Takotsubo syndrome (TS), an increasingly recognized acute cardiac disease entity, is characterized by a unique pattern of circumferential and typically regional left ventricular wall motion abnormality resulting in a conspicuous transient ballooning of the left ventricle during systole. The mechanism of the disease remains elusive. However, the sudden onset of acute myocardial stunning in a systematic pattern extending beyond a coronary artery territory; the history of a preceding emotional or physical stress factor in two thirds of cases; the signs of sympathetic denervation at the regions of left ventricular dysfunction on sympathetic scintigraphy; the finding of myocardial edema and other signs consistent with (catecholamine-induced) myocarditis shown by cardiac magnetic resonance imaging; and the contraction band necrosis on histopathological examination all argue strongly for the involvement of the cardiac sympathetic nervous system in the pathogenesis of TS. In this narrative review, extensive evidence in support of local cardiac sympathetic nerve hyperactivation, disruption and norepinephrine spillover causing TS in predisposed patients is provided., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

Transient left ventricular dysfunction in patients under emotional stress, also known as Takotsubo cardiomyopathy, has been recognized as a distinct clinical entity. Recent studies have supported the concept notion that the cardiovascular system is regulated by cortical modulation. A network consisting of the insular cortex (Ic), anterior cingulate gyrus, and amygdala plays a crucial role in the regulation of the central autonomic nervous system in relation to emotional stress such as anxiety, fear and sadness. Because the Ic is located in the region of the middle cerebral arteries, its structure tends to be exposed to a higher risk of cerebrovascular disease. Ic damage has been associated with myocardial injury, increased brain natriuretic peptide, and the incidence of Takotsubo cardiomyopathy. Because Ic damage has been associated with increased sympathetic nervous system activity, Ic damage is suggested to have a pivotal role in the pathophysiology of Takotsubo cardiomyopathy. In this review, we focus on the role of the Ic as a mediator for the cardiovascular system in relation to emotional stress, and we summarizes the current knowledge on the relationships between the Ic and Takotsubo cardiomyopathy., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.)

Takotsubo syndrome is typically characterized by acute reversible impairment of apical and mid -left ventricular systolic function. The pathophysiology is complex and remains to be completely understood. A catecholamine surge appears to be a central feature. Patients with prior history of psychiatric disorders have a predisposition. The putative role of a switch in b-adrenoceptor signalling resulting in negative inotropy remains uncertain. Downregulation of noncritical cellular functions may offer some protection in preventing irreversible cellular necrosis. Microvascular function is a common occurrence in these patients., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Takotsubo syndrome is a unique clinical condition of acute heart failure and reversible left ventricular dysfunction frequently precipitated by sudden emotional or physical stress. There is growing evidence that exaggerated sympathetic stimulation is central to the pathogenesis of this syndrome. Precisely how catecholamines mediate myocardial stunning in takotsubo syndrome remains incompletely understood; but possible mechanisms include epicardial spasm, microvascular dysfunction, direct adrenergic-receptor-mediated myocyte injury, and systemic vascular effects that alter ventricular-arterial coupling. Risk factors that increase sympathetic tone and/or catecholamine sensitivity may render individuals particularly susceptible to takotsubo syndrome during episodes of acute stress., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Recent literature has implicated severe neurologic injuries, such as aneurysmal subarachnoid hemorrhage, as a cause of cardiac dysfunction, impaired hemodynamic function, and poor outcomes. Mechanistic links between the brain and the heart have been explored in detail over the past several decades, and catecholamine excess, neuroendocrine dysfunction, and unchecked inflammation all likely contribute to the pathophysiologic process. Although cardiac dysfunction has also been described in other disease paradigms, including septic shock and thermal injury, there is likely a common underlying pathophysiology. In this review, we will examine the pathophysiology of cardiac dysfunction after neurologic injury, discuss the evidence surrounding cardiac dysfunction after different neurologic injuries, and suggest future research goals to gain knowledge and improve outcomes in this patient population., (Copyright © 2016 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.)

The low molecular weight protein tyrosine phosphatase (LMPTP), encoded by the ACP1 gene, is a ubiquitously expressed phosphatase whose in vivo function in the heart and in cardiac diseases remains unknown. To investigate the in vivo role of LMPTP in cardiac function, we generated mice with genetic inactivation of the Acp1 locus and studied their response to long-term pressure overload. Acp1(-/-) mice develop normally and ageing mice do not show pathology in major tissues under basal conditions. However, Acp1(-/-) mice are strikingly resistant to pressure overload hypertrophy and heart failure. Lmptp expression is high in the embryonic mouse heart, decreased in the postnatal stage, and increased in the adult mouse failing heart. We also show that LMPTP expression increases in end-stage heart failure in humans. Consistent with their protected phenotype, Acp1(-/-) mice subjected to pressure overload hypertrophy have attenuated fibrosis and decreased expression of fibrotic genes. Transcriptional profiling and analysis of molecular signalling show that the resistance of Acp1(-/-) mice to pathological cardiac stress correlates with marginal re-expression of fetal cardiac genes, increased insulin receptor beta phosphorylation, as well as PKA and ephrin receptor expression, and inactivation of the CaMKIIδ pathway. Our data show that ablation of Lmptp inhibits pathological cardiac remodelling and suggest that inhibition of LMPTP may be of therapeutic relevance for the treatment of human heart failure., (© 2015 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.)

Takotsubo cardiomyopathy (Tc) is a transient left ventricular apical ballooning syndrome, with symptoms and signs of acute myocardial infarction. Tc syndrome, which occurs predominantly in postmenopausal women, is characterized by increase of sympathetic activity. Studies on the gender-specific differences in sympatho-vagal regulation and functional cerebral asymmetry (FCA) imply that female pattern of dominance is characterized by the left hemisphere, which is believed to have parasympathetic predominance, whereas male pattern indicates dominance of the right hemisphere, which is believed to have sympathetic predominance. Fluctuating levels of female sex steroids are supposed to change FCA, modulating transcallosal inter-hemispheric inhibition across the menstrual cycle. The findings suggest that FCA is enhanced during the low steroid phase (menstrual phase), whereas, during high estrogen and/or progesterone phases (follicular and luteal phase) FCA is reduced. This theory is in line with concept of decreased magnitude of inter-hemispheric cortical lateralization in premenopausal women compared to men and postmenopausal women. Therefore, if postmenopausal women are more lateralized for a variety of cerebral functions, they have less balanced equilibrium between the right-sided sympathetic and left-sided parasympathetic predominance. Decrease of endogenous female sex steroid levels in postmenopausal women leads to reduced influence of estrogens to the left hemisphere, which is believed to have parasympathetic predominance. If both of these mechanisms result in sympatho-vagal imbalance, increasing sympathetic system activity in postmenopausal women, it seems reasonable why postmenopausal women became more susceptible to sympathetically-mediated syndromes such as Takotsubo cardiomyopathy., (Copyright © 2015 Elsevier Ltd. All rights reserved.)