Exploring the Pathophysiology of Takotsubo Cardiomyopathy

Stabilization of low-cost phase change materials for thermal energy storage applications

Sodium sulfate decahydrate (Na₂SO₄^.10H₂O, SSD), a low-cost phase change material (PCM), can store thermal energy. However, phase separation and unstable energy storage capacity (ESC) limit its use. To address these concerns, eight polymer additives-sodium polyacrylate (SPA), carboxymethyl cellulose (CMC), Fumed silica (SiO₂), potassium polyacrylate (PPA), cellulose nanofiber (CNF), hydroxyethyl cellulose (HEC), dextran sulfate sodium (DSS), and poly(sodium 4-styrenesulfonate) (PSS)-were used to explore several stabilization mechanisms. The ESC of PCMs deteriorated when thickeners, SPA, PPA, and CNF, were added. DSS-modified PCMs exhibited greater stability up to 150 cycles. Rheology measurements indicated that DSS did not impact SSD viscosity significantly during stabilization. Dynamic light scattering showed that DSS reduces SSD particle size and electrostatically suspends salt particles in a stable homogeneous solution, avoiding phase separation. This study proposes a promising method to improve the thermal stability of salt hydrate PCMs by utilizing polyelectrolyte-salt hydrate mixture for thermal energy storage applications.

Age-sex effect on in-hospital complications and mortality in patients with Takotsubo syndrome. Insights from the National Inpatient Sample

Age and sex differences in Takotsubo syndrome (TTS) are still a matter of debate. The present study aimed to evaluate the difference in cardiovascular (CV) risk factors, CV disease, in-hospital complications, and death within different sex-age groups. Using the National Inpatient Sample database between 2012 and 2016, 32,474 patients older than 18 years of age hospitalized with the primary diagnosis of TTS were identified. A total of 32,474 patients were enrolled; 27,611 (85.04%) were female. CV risk factors were higher in females, while CV diseases and in-hospital complications were significantly higher in males. The mortality in males was twice as high as that of female patients (9.83% versus 4.58%, p<0.01), and in the logistic regression model after adjustment for confounders, the odds ratio (OR) was 1.79, the confidence interval was 1.60-2.02, and p<0.01. After dividing the group based on age, in-hospital complications were inversely related to age in both sexes, and the length of in-hospital stay was double in the youngest group compared to the oldest one. Mortality increased progressively with age in both groups but was constantly higher in males for each age group. Multiple logistic regression analysis for mortality was performed for the two sexes separately and for the three age groups, considering the youngest one as the reference group. In females, the OR was 1.59 and 2.88, respectively, for groups 2 and 3; for males, the OR was 1.92 and 3.15, all of them statistically significant (p<0.01). In-hospital complications were more common in younger patients with TTS, particularly in males. Mortality was positively correlated with age for both sexes, but mortality was higher in males compared to females in all age groups.

The Cardiovascular Side Effects of Electroconvulsive Therapy and Their Management

ABSTRACT

Electroconvulsive therapy (ECT) remains stigmatized in the broader medical community because of misunderstandings about treatment procedures, mortality rates, and cardiovascular complications. Electroconvulsive therapy causes periprocedural hemodynamic variability because of the surges in parasympathetic and sympathetic nervous systems after the administration of the electrical charge. Patients experience an increase in cardiac workload, which is potentially dangerous for patients with preexisting heart disease. Several findings suggest that cardiac complications occur most frequently in patients with underlying cardiovascular disease. We describe the cardiovascular complications that may result from ECT treatment and offer insight on how to mitigate these concerns if they occur. PubMed was queried using terms "electroconvulsive therapy" and "cardiovascular adverse effects." A table is provided with the common cardiovascular side effects of ECT and the most recent evidence-based treatment strategies to manage them. Generally, ECT is a safe procedure in which complications are minor and manageable. Most major complications caused by ECT are related to the cardiovascular system; however, with an appropriate pre-ECT evaluation and a comprehensive multidisciplinary team approach, the cardiovascular complications can be well managed and minimized. Providing proper cardiac clearance can prevent cardiac complications and provide timely care to treatment-resistant populations who are at risk for excessive morbidity and suicide.

The Impact of COVID-19 on Nuclear Medicine Operations Including Cardiovascular Manifestations in the USA

The pandemic of coronavirus 2019 disease (COVID-19) not only directly causes high morbidity and mortality of the disease, but also indirectly affects patients with pre-existing medical conditions, particularly cardiovascular diseases, with delayed or deferred outpatient care and procedure including nuclear medicine studies because of concerns about exposure to the virus. In this article, the impact of COVID-19 on hospital operation and nuclear medicine practice in the United States along with recommendations and guidance from major academic organizations are presented. Safe operation of specific nuclear medicine scans, such as lung scintigraphy and nuclear cardiac imaging, are reviewed in the context of balancing benefits to patients against the risk of exacerbating the spread of the virus. Thoughtful reintroduction of nuclear medicine services are discussed based on ethical considerations that maximize benefits to those who are likely to benefit most, taking into consideration baseline health inequities, and ensuring that all decisions reflect best available evidence with transparent communication. Finally, potential correlation between decreased volume of nuclear cardiac studies performed during the pandemic and corresponding increased deaths from ischemic and hypertensive cardiac disease is discussed.

Blood norepinephrine/epinephrine/dopamine measurements in 108 patients with takotsubo syndrome from the world literature: pathophysiological implications

OBJECTIVES

Release of norepinephrine (NE) from neuronal cardiac nerve endings and/or blood-borne catecholamines (CATs), mainly epinephrine (EPI), may mediate TTS. The aim of this study was to document the levels of NE, EPI, and dopamine (DA) in patients with TTS.

MATERIALS AND METHODS

A qualitative/quantitative meta-analysis of CATs and their relationship to age, gender, and triggers, was carried out, employing the world literature on TTS, published in PubMed.

RESULTS

NE/EPI/DA in108 patients with TTS, 65.2 ± 16.4 years old, 89 (82.4%) women, revealed that: NE was measured more frequently than EPI, and EPI than DA; the timing of the measurements was variable; CATs were reported variably (qualitatively/quantitatively/with/without upper limits of normal); NE/EPI or NE/EPI/DA rose to the same degree; CATs were normal, or mildly/moderately elevated, with only 6 patients showing markedly elevated NE/EP/DA; NE, EPI, and DA were similar in patients with physical triggers and NE was similar in patients with physical, emotional, or no triggers (p = 0.47); EPI was higher than NE in patients with emotional triggers and EPI was higher in patients with emotional than physical triggers (p = 0.012); NE, EPI, and DA rose to the same proportion in men and women; types of TTS triggers were distributed proportionally in men and women.

CONCLUSION

NE, EPI, and DA rise proportionally in patients with TTS; CATs are mildly/moderately, and rarely markedly elevated; measurements of CATs should become more systematised; although CATs may not be essential for TTS diagnosis, they may contribute to prognosis and elucidation of the pathophysiology of TTS.

The role of adrenergic and muscarinic receptors in stress-induced cardiac injury

Takotsubo syndrome (TS) is a rare but dangerous disease that can be fatal. The pathogenesis of TS is not well understood because there is no animal model of TS that fully mimics TS. It has now been documented that stress exposure (24 h) of rats induced the state which is similar TS in human: contracture damage of myofibrils, elevation of the serum creatine kinase MB level, increased ^99mTc-pyrophosphate (^99mTc-PYP) accumulation in the heart, QTc interval prolongation, and contractility dysfunction of the heart. Immobilization stress resulted in an increase in coronary blood flow. Emotional stress increased the serum catecholamine level. Blockade of β₁-adrenergic receptor (AR) prevented stress-induced cardiac injury (SICI). Blockade of β₂-AR aggravated stress-induced cardiac injury. Stimulation of β₂-AR increased cardiac tolerance to stress. Inhibition of β₃-AR, α₁-AR had no effect on SICI. Blockade of peripheral muscarinic receptors or α₂-AR aggravated SICI. Pretreatment with the selective β₁-AR antagonist atenolol attenuates stress-induced cardiac contractility dysfunction, but recovery of cardiac contractility is not complete. There is indirect evidence that circulating catecholamines play an important role in SICI. Consequently, the activation of β₁-AR plays a significant role in SICI. However, there are other receptors which are also involved in SICI and require further investigation.

Stress-associated neurobiological activity associates with the risk for and timing of subsequent Takotsubo syndrome

AIMS

Activity in the amygdala, a brain centre involved in the perception of and response to stressors, associates with: (i) heightened sympathetic nervous system and inflammatory output and (ii) risk of cardiovascular disease. We hypothesized that the amygdalar activity (AmygA) ratio is heightened among individuals who develop Takotsubo syndrome (TTS), a heart failure syndrome often triggered by acute stress. We tested the hypotheses that (i) heightened AmygA precedes development of TTS and (ii) those with the highest AmygA develop the syndrome earliest.

METHODS AND RESULTS

Individuals (N=104, median age 67.5 years, 72% female, 86% with malignancy) who underwent clinical 18 F-FDG-PET/CT imaging were retrospectively identified: 41 who subsequently developed TTS and 63 matched controls (median follow-up 2.5 years after imaging). AmygA was measured using validated methods. Individuals with (vs. without) subsequent TTS had higher baseline AmygA (P=0.038) after adjusting for TTS risk factors. Further, AmygA associated with the risk for subsequent TTS after adjustment for risk factors [standardized hazard ratio (95% confidence interval): 1.643 (1.189, 2.270), P=0.003]. Among the subset of individuals who developed TTS, those with the highest AmygA (>mean + 1 SD) developed TTS ∼2 years earlier after imaging vs. those with lower AmygA (P=0.028).

CONCLUSION

Higher AmygA associates with an increased risk for TTS among a retrospective population with a high rate of malignancy. This heightened neurobiological activity is present years before the onset of TTS and may impact the timing of the syndrome. Accordingly, heightened stress-associated neural activity may represent a therapeutic target to reduce stress-related diseases, including TTS.

Iatrogenic Takotsubo Cardiomyopathy Following Overdose Norepinephrine Administration During Percutaneous Coronary Intervention

Takotsubo cardiomyopathy (TTC) is characterized by reversible ventricular dysfunction induced by endogenous and, occasionally, exogenous catecholamine. We present a report on a patient who developed TTC and cardiogenic shock during percutaneous coronary intervention (PCI) secondary to inadvertent norepinephrine administration. His hemodynamic status and cardiac function were totally restored within 1 week after hemodynamic support using intra-aortic balloon pump without sequela. Thus, TTC should be considered once a patient presents with symptoms mimicking acute coronary syndrome (ACS) after catecholamine administration.

A novel mechanism of protection against isoproterenol-induced cardiac inflammation via regulation of the SIRT1/NRF2 signaling pathway with a natural SIRT1 agonist

Stress-induced cardiomyopathy (SIC) is associated with high mortality rates, potentially due to a lack of available therapies. To facilitate the identification of therapeutic targets for SIC, we explored the detailed mechanisms of disease onset and progression using a mouse model. Over-activation of the β-adrenergic receptor (β-AR) upon stress leads to inflammasome activation, cytokine cascades, macrophage infiltration, and pathological cardiac remodeling in mice, mimicking SIC. However, the detailed mechanisms by which acute β-AR stimulation induces cardiac inflammation remain elusive. We found that resveratrol (RSV) could attenuate isoproterenol-induced cardiac inflammation in mice, suggesting that RSV might be a promising therapeutic option in SIC. Mechanistically, we revealed that the SIRT1/NRF2 signaling pathway is the bona fide target of RSV and plays a significant role in the RSV-induced protective effect in cardiac inflammation.

Forme Fruste in Recurring Mid-Ventricular Variant of Takotsubo Cardiomyopathy

BACKGROUND Takotsubo cardiomyopathy (TC) is characterized as acute left ventricular dysfunction precipitated by intense emotional or physiological stress. The mid-ventricular variant of TC usually has akinesis, with or without ballooning of the mid-ventricular segment, and a hyperdynamic base and apex. Recurrence of the typical and atypical (reversed and mid-ventricular type) forms has been reported in only a very small number of cases. We report a forme fruste presentation of mid-ventricular variant of TC. CASE REPORT A 69-year-old woman with a prior history of stress-induced cardiomyopathy presented with complaint of moderate intensity, persistent, sub-sternal chest discomfort. She reported that her symptoms were similar to those she had during a previous hospitalization in 2015, and this time cited the death of her mother as an inciting stressor. No significant obstructive flow-limiting coronary artery disease was found on cardiac catheterization. However, the left ventriculogram was suggestive of mid-ventricular pattern of TC. Her first symptomatic episode of apparent TC did not reveal completion of the mid-ventricular pattern of the TC variant. The subsequent episode, during this hospitalization, manifested as a completed version of her initial apparent forme fruste of mid-ventricular variant of TC. CONCLUSIONS TC may present in a myriad of clinical forms that must be considered in the evaluation of patients with suspected acute coronary syndromes or cardiomyopathy. Treatment is mainly supportive, and recurrence rates range from 7.7% to 11.4%. To the best of our knowledge, this forme fruste presentation has not been previously reported in recurrent variants of TC.

Cardioprotective properties of opioid receptor agonists in rats with stress-induced cardiac injury

The objectives of this study were to investigate the role of endogenous opioids in the mediation of stress-induced cardiomyopathy (SIC), and to evaluate which opioid receptors regulate heart resistance to immobilization stress. Wistar rats were subjected to 24 h immobilization stress. Stress-induced heart injury was assessed by 99mTc-pyrophosphate accumulation in the heart. The opioid receptor (OR) antagonists (naltrexone, NxMB - naltrexone methyl bromide, MR 2266, ICI 174.864) and agonists (DALDA, DAMGO, DSLET, U-50,488) were administered intraperitoneally prior to immobilization and 12 h after the start of stress. In addition, the selective micro OR agonists PL017 and DAMGO were administered intracerebroventricularly prior to stress. Finally pretreatment with guanethidine was used. Naltrexone did not alter the cardiac 99mTc-PP accumulation in stressed rats. NxMB aggravated stress-induced cardiomyopathy (P=0.005) (SIC). The selective micro OR agonist DALDA, which does not cross the blood-brain barrier, completely prevented (P=0.006) SIC. The micro OR agonist DAMGO exhibited weaker effect than DALDA. The selective delta ligand (DSLET) and kappa OR ligand (U-50,488) did not alter stress-induced 99mTc-pyrophosphate accumulation in the heart. Intracerebroventricular administration of the micro OR agonists aggravated SIC. Pretreatment with guanethidine abolished this effect (P=0.01). Guanethidine alone exhibited cardioprotective properties. A stimulation of central micro OR promotes an appearance of SIC. In contrast, stimulation of peripheral micro OR contributes to an increase in cardiac tolerance to stress.

Takotsubo Cardiomyopathy Associated with Polycythemia Vera

Takotsubo cardiomyopathy is characterized by transient apical ballooning with preserved basal ventricular function triggered by physical or emotional stressors. We present a case of a 75-year-old man referred to our facility for the management of acute myocardial infarction later diagnosed as takotsubo cardiomyopathy. We believe platelet-mediated adrenaline release from massive thrombocytosis might have been the precipitating factor for the pathogenesis of takotsubo cardiomyopathy.

Takotsubo cardiomyopathy in a young adult with transplanted heart: what happened to denervation?

This manuscript describes the first report of takotsubo cardiomyopathy in a young heart transplant recipient following angry debate. Our patient is a 21‐year‐old woman with cardiac transplant performed owing to right ventricular failure in congenital heart disease. Positive echocardiography with typical asymmetry of regional function, positive enzymes, and negative biopsy and angiography met the criteria for the diagnosis of takotsubo cardiomyopathy. Patient was discharged after 1 week in good clinical conditions and fully recovered cardiac function. The development of takotsubo cardiomyopathy in transplanted heart suggests that re‐innervation occurs, thus representing a target for catecholamine‐induced cardiac dysfunction.

Takotsubo Myocardiopathy and Hyperthyroidism: A Case Report and Literature Review

Patient: Male, 34

Final Diagnosis: Takotsubo myocardiopathy and hyperthyroidism

Symptoms: Chest pain • dyspnea

Medication: —

Clinical Procedure: —

Specialty: Cardiology