Plasma catecholamine levels in patients with takotsubo syndrome: Implications for the pathogenesis of the disease

Early Clinical Outcomes of Patients With Stress-Induced Cardiomyopathy Receiving Acute Mechanical Support in the US

Background

The role of acute mechanical circulatory support (aMCS) in patients with stress-induced cardiomyopathy (SIC) complicated by cardiogenic shock (CS) is not well studied. Here, we describe the incidence and outcomes of aMCS use in SIC-CS using a large national database.

Methods

Using the Nationwide Readmissions Database from January 2016 to November 2019, we identified patients hospitalized with SIC who received isolated intra-aortic balloon pump (IABP), microaxial flow pump (Impella, Abiomed), or extracorporeal membrane oxygenation (ECMO) during the index hospitalization.

Results

A total of 902 among 94,709 hospitalizations for SIC (1.0%) required aMCS during the index hospitalization: 611 had IABP (67.7%), 189 had Impella (21.0%) and 102 had ECMO (11.3%). Patients with ECMO or Impella had higher in-hospital mortality rates than those with IABP (37.3% vs 29.1% vs 18.5%, respectively). There was an increased adjusted risk of in-hospital death with Impella (adjusted odds ratio [aOR], 1.98; 95% CI, 1.12-3.49) and ECMO (aOR, 4.15; 95% CI, 1.85-9.32) vs IABP. Impella was associated with an increased adjusted risk of 30-day readmission compared to IABP (aOR, 2.53; 95% CI, 1.16-5.51). Patients with ECMO or Impella had a higher incidence of renal replacement therapy and vascular/bleeding complications compared to those who received IABP.

Conclusions

In this nationwide analysis using an administrative database, patients who received ECMO and Impella showed higher rates of in-hospital mortality, renal replacement therapy, and vascular/bleeding complications compared to those who received IABP. Patients with more comorbidities may receive more aggressive hemodynamic support which may account for observed mortality differences. Future prospective studies with objective and universal characterization of baseline clinical and hemodynamic characteristics of patients with CS secondary to SIC are needed.

Takotsubo syndrome: getting closer to its causes

Takotsubo syndrome (TTS) accounts for between 1 and 4% of cases presenting clinically as an acute coronary syndrome. It typically presents as a transient cardiac phenotype of left ventricular dysfunction with spontaneous recovery. More dramatic presentations may include cardiogenic shock or cardiac arrest. Despite progress in the understanding of the condition since its first description in 1990, considerable questions remain into understanding underlying pathomechanisms. In this review article, we describe the current published data on potential underlying mechanisms associated with the onset of TTS including sympathetic nervous system over-stimulation, structural and functional alterations in the central nervous system, catecholamine secretion, alterations in the balance and distribution of adrenergic receptors, the additive impact of hormones including oestrogen, epicardial coronary or microvascular spasm, endothelial dysfunction, and genetics as potentially contributing to the cascade of events leading to the onset. These pathomechanisms provide suggestions for novel potential therapeutic strategies in patients with TTS including the role of cognitive behavioural therapy, beta-blockers, and endothelin-A antagonists. The underlying mechanism of TTS remains elusive. In reality, physical or emotional stressors likely trigger through the amygdala and hippocampus a central neurohumoral activation with the local and systemic secretion of excess catecholamine and other neurohormones, which exert its effect on the myocardium through a metabolic switch, altered cellular signalling, and endothelial dysfunction. These complex pathways exert a regional activation in the myocardium through the altered distribution of adrenoceptors and density of autonomic innervation as a protective mechanism from myocardial apoptosis. More research is needed to understand how these different complex mechanisms interact with each other to bring on the TTS phenotype.

Establishment and effect evaluation of a stress cardiomyopathy mouse model induced by different doses of isoprenaline

The optimum dose of isoprenaline (ISO) required to induce stress cardiomyopathy (SC) in mice is not known. The present study aimed to investigate the dose-response association and determine the optimum dose of ISO to establish a high-morbidity/low-mortality SC mouse model to simulate the clinical symptoms of SC. A total of 72 6-week-old wild-type female mice (C57BL/6) were randomly divided into control mice administered normal saline and mice treated with increasing ISO concentrations (5, 10, 25, 50 and 100 mg/kg ISO intraperitoneal injections daily for 14 consecutive days). All mice were analysed by body weight assessment, open field test (OFT), echocardiography (Echo), electrocardiogram (ECG), assessment of myocardial pathology and quantification of cortisol, brain natriuretic peptide (BNP), cardiac troponin T (cTnT), catecholamine (CA) and C-reactive protein (CRP). Compared with the control group, the 25 and 50 mg/kg ISO groups exhibited the most prominent weight changes and lower mortality. The open-field test showed a significant decrease in autonomous activity behaviour in the 25 and 50 mg/kg ISO groups compared with the control group (P<0.05). Echo revealed that the apex of the heart was balloon-like in the 25 and 50 mg/kg ISO groups, along with prominent left ventricular dyskinesia. ECG showed a significant increase in ST segment amplitude, QT interval and Q amplitude (P<0.05) in the 25 and 50 mg/kg ISO group compared with the control group. Haematoxylin and eosin staining of heart tissue showed a disordered arrangement of myocardial cells, dissolution of myocardial fibres and cytoplasm, notable widening of myocardial cell space, oedema and hyperaemia of the interstitium, whereas heart tissue of the control group was structurally intact. Compared with the control group, the 25 and 50 mg/kg ISO groups exhibited significantly higher levels of cortisol, BNP, cTNT, CA and CRP (P<0.05). A high-incidence low-mortality SC model was successfully and stably developed by administration of 25 and 50 mg/kg ISO. Such models may provide a basis for the development of other animal models of SC.

Isoprenaline modified the lipidomic profile and reduced β-oxidation in HL-1 cardiomyocytes: In vitro model of takotsubo syndrome

Recent studies have suggested a pathogenetic link between impaired mitochondria and Takotsubo syndrome (TTS), which is closely connected with catecholamine overstimulation, poor outcomes, and changes in lipid metabolism. We investigated the changes in lipid metabolism at the level of fatty acid β-oxidation and changes in the intracellular lipidomic spectrum. The immortalized cell line of HL-1 cardiomyocytes was used in this study as an established in vitro model of TTS. The cells were exposed to the non-selective β-agonist isoprenaline (ISO) for acute (2 h) and prolonged (24 h) periods. We investigated the impact on mitochondrial adenosine 5’-triphosphate (ATP) production and β-oxidation using real-time cell metabolic analysis, total lipid content, and changes in the lipidomic spectrum using high-performance liquid chromatography (HPLC) and mass spectrometry. Furthermore, modifications of selected lipid transporters were determined using real-time – polymerase chain reaction (RT-PCR) and/or Western blot techniques. By choosing this wide range of targets, we provide a detailed overview of molecular changes in lipid metabolism during catecholamine overstimulation. The present study demonstrates that acute exposure to ISO decreased ATP production by up to 42.2%, and prolonged exposure to ISO decreased β-oxidation by 86.4%. Prolonged exposure to ISO also increased lipid accumulation by 4%. Lipid spectrum analysis of prolonged exposure to ISO showed a reduced concentration of cardioprotective and an increased concentration of lipotoxic lipid molecules during long-term exposure. Decreased lipid utilization can lead to higher intracellular lipid accumulation and the formation of lipotoxic molecules. Changes in the lipid spectrum can induce pathophysiological signaling pathways leading to cardiomyocyte remodeling or apoptosis. Thus, changes in lipid metabolism induced by excessive doses of catecholamines may cause TTS and contribute to a progression of heart failure, which is at increased risk after a TTS episode.

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.

Oxidative Stress in Takotsubo Syndrome-Is It Essential for an Acute Attack? Indirect Evidences Support Multisite Impact Including the Calcium Overload-Energy Failure Hypothesis

Indirect evidences in reviews and case reports on Takotsubo syndrome (TTS) support the fact that the existence of oxidative stress (OS) might be its common feature in the pre-acute stage. The sources of OS are exogenous (environmental factors including pharmacological and toxic influences) and endogenous, the combination of both may be present, and they are being discussed in detail. OS is associated with several pathological conditions representing TTS comorbidities and triggers. The dominant source of OS electrones are mitochondria. Our analysis of drug therapy related to acute TTS shows many interactions, e.g., cytostatics and glucocorticoids with mitochondrial cytochrome P450 and other enzymes important for OS. One of the most frequently discussed mechanisms in TTS is the effect of catecholamines on myocardium. Yet, their metabolic influence is neglected. OS is associated with the oxidation of catecholamines leading to the synthesis of their oxidized forms - aminochromes. Under pathological conditions, this pathway may dominate. There are evidences of interference between OS, catecholamine/aminochrome effects, their metabolism and antioxidant protection. The OS offensive may cause fast depletion of antioxidant protection including the homocystein-methionine system, whose activity decreases with age. The alteration of effector subcellular structures (mitochondria, sarco/endoplasmic reticulum) and subsequent changes in cellular energetics and calcium turnover may also occur and lead to the disruption of cellular function, including neurons and cardiomyocytes. On the organ level (nervous system and heart), neurocardiogenic stunning may occur. The effects of OS correspond to the effect of high doses of catecholamines in the experiment. Intensive OS might represent "conditio sine qua non" for this acute clinical condition. TTS might be significantly more complex pathology than currently perceived so far.

Plasma catecholamine levels in the acute and subacute stages of takotsubo syndrome: Results from the Stockholm myocardial infarction with normal coronaries 2 study

AIMS

It is well-accepted that takotsubo syndrome (TS) is characterized by a massive surge of plasma catecholamines despite lack of solid evidence. The objective of this study was to examine the hypothesis of a massive catecholamine elevation in TS by studying plasma-free catecholamine metabolites in patients participating in the Stockholm myocardial infarction (MI) with normal coronaries 2 (SMINC-2) study where TS constituted more than one third of the patients.

METHODS AND RESULTS

The patients included in the SMINC-2 study were classified, according to cardiac magnetic resonance (CMR) imaging findings (148 patients), which was performed at a median of 3 days after hospital admission. Plasma-free catecholamine metabolites; metanephrine, normetanephrine, and methoxy-tyramine were measured on day 2-4 after admission. Catecholamine metabolite levels were available in 125 patients. One hundred and ten (88%) of the 125 patients included in SMINC-2 study, and 38 (86.4%) of the 44 patients with TS had completely normal plasma metanephrine and normetanephrine levels. All patients had normal plasma methoxy-tyramine levels. Fourteen (11.2%) of the 125 patients included in SMINC-2 study, and 5 (11.6%) of the 43 patients with TS had mild elevations (approximately 1.2 times the upper normal limits) of either plasma metanephrine or normetanephrine. One patient with pheochromocytoma-triggered TS had marked elevation of plasma metanephrine and mild elevation of plasma normetanephrine. There were no significant differences between the number or degree of catecholamine metabolite elevations between the different groups of patients with CMR imaging diagnosis included in SMINC-2 study.

CONCLUSION

There was no evidence of massive catecholamine elevations in the acute and subacute stages of TS apart from one patient with pheochromocytoma-induced TS. Most of the TS patients had normal catecholamine metabolites indicating that blood-borne catecholamines do not play a direct role in the pathogenesis of TS.

Chromogranin-A serum levels in patients with takotsubo syndrome and ST elevation acute myocardial infarction

BACKGROUND

Sympathergic hyperactivity is considered one of the main trigger precipitating takotsubo syndrome (TTS). Chromogranin-A (CgA), a prognostic biomarker of sympatho-adrenal activation, is markedly high in acute coronary syndrome (ACS) and heart failure (HF), but its role in TTS is unknown.

METHODS

CgA serum levels from patients with TTS and symptoms onset <24 hours were consecutively evaluated and compared with anterior ST-elevation myocardial infarction (STEMI) patients from November 2016 to December 2019. Short and long-term follow-up data were recorded.

RESULTS

Eleven women with TTS and 10 subjects with anterior STEMI were analyzed and compared; differences were not significant in terms of age, gender and cardiovascular risk factors. NT-pro-BNP levels were similar (9,887 ± 12,170 vs 8,969 ± 15,053 pg/ml, p = .88), while troponin-I levels were higher in patients with STEMI (4 ± 3.2 vs 13.3 ± 10 ng/dl, p = .03). CgA admission levels were significantly lower in TTS patients (2.2 ± 1.5 vs 7.3 ± 6.2 nMol/l, p = .017), even after multivariable correction for principal bias. CgA levels correlated with NTproBNP levels (p = .02) and were higher in subjects with in-hospital events (3.7 ± 1.1 vs 1.6 ± 1.2 nMol/l, p = .03), even after multivariable forward stepwise analysis (p < .01). CgA levels <3.25 nMol/l (AUC 0.754, 95% C.I. 0.54-0.968) were able to discriminate TTS from anterior STEMI (negative predictive power of 99%).

CONCLUSIONS

Systemic CgA levels in the acute phase of TTS are lower than in anterior STEMI, possibly indicating a greater myocardial catecholamine release rather than adrenal.

Autonomic nervous system in Takotsubo syndrome

Takotsubo syndrome (TTS) is an acute and usually reversible heart failure syndrome with symptoms resembling acute myocardial infarction, however, without obstruction of coronary arteries. In the majority of cases, TTS is preceded by emotional or physical stress and the disease concerns mainly postmenopausal women. Although several hypotheses have been introduced, the pathogenesis of TTS is controversial and still remains to be determined. As reported in recent studies, the role of the autonomic nervous system (ANS) seems to be pivotal in the pathogenesis of TTS. Therefore, the aim of this article is to summarize and discuss the current knowledge of the pathogenesis of TTS with a special focus on the ANS.

Takotsubo syndrome: between evidence, myths, and misunderstandings

Takotsubo syndrome (TS) is an acute cardiac condition characterized by transient wall motion abnormalities mostly of the left ventricle. First described in 1990, TS has gained substantial attention during the past 15 years. However, the disease is still underdiagnosed. Prospective studies on TS are largely lacking, and the condition remains incompletely understood. In addition, significant misconceptions and misunderstandings are evident, contributing to potentially severe underestimation. Here, we review important aspects of TS with a focus on pitfalls, misinterpretations, and knowledge gaps considered important during diagnosis and management of the disease.

International Expert Consensus Document on Takotsubo Syndrome (Part I): Clinical Characteristics, Diagnostic Criteria, and Pathophysiology

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.

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Plasma Epinephrine Level and its Causal Link to Takotsubo Syndrome Revisited: Critical Review with a Diverse Conclusion

Takotsubo syndrome (TS) is a recognized acute cardiac syndrome with a clinical presentation resembling that of an acute coronary syndrome (ACS). The defining feature of TS is the reversible left ventricular wall motion abnormality (LVWMA), which has a unique circumferential pattern resulting in a conspicuous ballooning of the left ventricle during systole, and extending beyond the coronary artery supply territory. The pathogenesis of TS is still elusive and several pathophysiological mechanisms have been proposed. A common portrayal of the syndrome in the literature is that the disease is characterized by massive surge of plasma catecholamines including epinephrine. Based on the assumption of massive plasma epinephrine elevation, some investigators hypothesized that the circulatory plasma epinephrine plays a pivotal role in the pathogenesis of TS. One typical such hypothesis is epinephrine induced switch in signal trafficking causing apical or mid-apical ballooning in TS. In-depth analysis of the literature reveals that no study with certainty has shown "massive" plasma epinephrine elevations in TS. Furthermore, the literature evidences challenging the epinephrine-induced switch in signal trafficking are substantial. In this review, sufficient data, indicating that the plasma epinephrine in TS is either normal or moderately elevated in all studies, are provided. Noteworthy, epinephrine may act as a trigger factor for TS-induction but there is no evidence for a direct causal link between epinephrine and TS.

International Expert Consensus Document on Takotsubo Syndrome (Part I): Clinical Characteristics, Diagnostic Criteria, and Pathophysiology

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.

Association of prolonged QTc interval with Takotsubo cardiomyopathy: A neurocardiac syndrome inside the mystery of the insula of Reil

The Takotsubo cardiomyopathy is often considered autochthonous to the heart, although the primary problem may be not in the heart muscle itself. Instead, similar to several Takotsubo-like cardiac pathologies seen in acute neurological diseases, it may reflect the capacity of the nervous system to injure the heart. Persuasive evidence exists that shocking emotional stress promotes direct heart injuries. Moreover, clinical and laboratory research shows that cardiac structural damage can occur in the presence of a normal heart, especially in the context of seizures, stroke, and traumatic brain injury or under conditions of psychological stress. The aim of this review is to summarize the clinical implications of these observations, several of which focus on the pivotal role of the insula of Reil in the brain-heart connection, to unravel the mystery of Takotsubo cardiomyopathy pathogenesis.

Diabetes mellitus prevalence in patients with takotsubo syndrome: the case of the brain-heart disconnect

BACKGROUND

Hyperactive autonomic nervous system (ANS) is among the postulated pathophysiologic mechanisms of takotsubo syndrome (TTS). Diabetes mellitus (DM) with its associated ANS peripheral neuropathy could exert a "protective" influence for the emergence of TTS.

METHODS

A patient-based meta-analysis of the data obtained from all patients presented individually was carried out, focusing on age, gender, and history of hypertension (HTN) and DM.

RESULTS

The prevalences of HTN and DM for all 2,342 patients, aged 61.1 ± 17.3, 85.1% female, were 37.4% and 9.5%, for patients ≥ 60 years old were 45.8% and 11.7%, and for patients ≥65 years old were 48.2% and 12.3%, correspondingly. The prevalence of DM in patients with TTS is less than half of the world's and USA's elderly populations.

CONCLUSIONS

Prevalence of DM in patients with TTS is lower than in the general population, suggesting that DM, may have a "protective" effect for the emergence of TTS.

Basal wall hypercontraction of Takotsubo cardiomyopathy in a patient who had been diagnosed with dilated cardiomyopathy: a case report

BACKGROUND

Takotsubo cardiomyopathy is characterized by the basal hypercontractility and apical ballooning of the left ventriculum and T-wave inversion in the electrocardiogram. It has been suggested that Takotsubo cardiomyopathy might underlie the pathogenesis of persistent cardiac dysfunction; however, few reports are present demonstrating the advent of Takotsubo cardiomyopathy in patients with idiopathic cardiomyopathy.

CASE PRESENTATION

A 64-year-old women was admitted due to dyspnea on effort and lower extremity edema. She had been diagnosed with idiopathic dilated cardiomyopathy 2.5 years before owing to the reduced left ventricular ejection fraction (24%), normal coronary artery, and interstitial fibrosis of the myocardial samples. On admission, her electrocardiogram showed giant negative T wave in II, III, aVF, and precordial leads. Echocardiography showed dyskinesis of the left ventricular apex and hypercontraction of the basal wall, which had not been observed in the previous examinations. Coronary angiography showed normal coronary arteries, and apical ballooning and basal hypercontractility was confirmed by left ventriculography. On day 15 of admission, contraction of apical wall was recovered, and basal hypercontraction was disappeared.

CONCLUSION

The present case is the first report demonstrating appearance the transient basal wall hypercontraction along with the advent of Takotsubo cardiomyopathy in a patient diagnosed with dilated cardiomyopathy. Whether such findings are indicative of fair prognosis and have the utility of understanding the pathogenesis of dilated cardiomyopathy needs further investigation.

Epidemiology, pathogenesis, and management of takotsubo syndrome

Takotsubo syndrome is a recently recognized acute cardiac disease entity with a clinical presentation resembling that of an acute coronary syndrome. The typical takotsubo syndrome patient has a unique circumferential left (bi-) ventricular contraction abnormality profile that extends beyond a coronary artery supply territory and appears to follow the anatomical cardiac sympathetic innervation. The syndrome predominantly affects postmenopausal women and is often preceded by emotional or physical stress. Patients with predisposing factors such as malignancy and other chronic comorbidities are more prone to suffer from takotsubo syndrome. The pathogenesis of takotsubo syndrome is elusive. Several pathophysiological mechanisms involving myocardial ischemia (multivessel coronary artery spasm, microvascular dysfunction, aborted myocardial infarction), left ventricular outlet tract obstruction, blood-borne catecholamine myocardial toxicity, epinephrine-induced switch in signal trafficking, and autonomic nervous system dysfunction have been proposed. The syndrome is usually reversible; nevertheless, during the acute stage, a substantial number of patients develop severe complications such as arrhythmias, heart failure including pulmonary edema and cardiogenic shock, thromboembolism, cardiac arrest, and rupture. Treatment of precipitating factors, predisposing diseases, and complications is fundamental during the acute stage of the disease. The epidemiology, pathogenesis, and management of takotsubo syndrome are reviewed in this paper.

Drug-Induced Takotsubo Cardiomyopathy

BACKGROUND

The most plausible hypothesis for takotsubo cardiomyopathy (TCM) is a catecholamine surge. Direct administration of catecholamines or medications causing catecholamine surge is frequently used in clinical practice.

METHODS

A Medline/PubMed database search was conducted for case reports or series of drug-induced TCM. All reported cases of drug-induced TCM were systemically identified and analyzed.

RESULTS

We identified 157 cases of drug-induced TCM. Fifty-seven (36.3%) cases were related to the administration of exogenous catecholamines. In 50 (31.9%) other cases, there was potential adrenergic effect. This included drugs with adrenergic vasoconstriction properties (3.2%), hyperadrenergic state due to alcohol or opioid withdrawal (7.7%), inhibitors of catecholamine reuptake (14.7%), anaphylactic reaction that is accompanied by catecholamine release (3.2%), and psychological or somatic stress coinciding with the administration of a drug that was thought to be the culprit (3.2%). Overall, 68.2% of these drug-induced TCM cases were catecholamine related. In 14 (8.9%) cases, the likely etiology of cardiomyopathy was chemotherapy-induced coronary vasospasm.

CONCLUSION

Our systematic review showed that over two-thirds of drug-induced TCM cases were due to direct or indirect catecholamine stimulation. The lowest effective dose and shortest duration of catecholamines should be utilized, and alternative therapies should be considered if feasible.

The Sympathetic Nervous System in the Pathogenesis of Takotsubo Syndrome

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.

Clinical Features and Outcome of Pheochromocytoma-Induced Takotsubo Syndrome: Analysis of 80 Published Cases

Myriads of physical stress factors including pheochromocytoma have been reported triggering takotsubo syndrome (TS). The aim of this study was to report on the clinical features and outcome of pheochromocytoma-induced TS (Pheo-TS) in a large cohort of patients. Eighty published cases of Pheo-TS were retrieved from the literature and compared with 1,750 cases of all patients with TS (All-TS) published recently by Templin et al. Patients with Pheo-TS were on average 19.87 years younger than those with All-TS (p <0.0001). The women were still predominating in Pheo-TS but significantly in a lower percentage (70% in Pheo-TS vs 89.8% in All-TS, p <0.00001). Almost 1/3 (30%) of Pheo-TS cases had basal TS pattern compared with 2.2% of cases in All-TS (p <0.00001) and 1/5 (20%) had global TS compared with no cases in All-TS. Two thirds of Pheo-TS cases (67.9%) developed complications, which was significantly higher than complication rates in All-TS (21.8%), but there was no difference in the inhospital mortality between the 2 studies. The most important risk factors for the development of complications in Pheo-TS were age <50 years and global and basal TS localization patterns. The recurrence rate of 17.7% in Pheo-TS was significantly higher than the 3.26% in All-TS (p <0.00001). In conclusion, Pheo-TS is characterized by a dramatic clinical presentation with high complication rates and relatively high recurrence rate. Patients with Pheo-TS are significantly younger than All-TS. The TS localization pattern in Pheo-TS differed significantly from All-TS with basal pattern in almost 1/3 of cases and global pattern in 1/5 of the cases.

Reversible Cardiomyopathies

Cardiomyopathies (CMs) have many etiological factors that can result in severe structural and functional dysregulation. Fortunately, there are several potentially reversible CMs that are known to improve when the root etiological factor is addressed. In this article, we discuss several of these reversible CMs, including tachycardia-induced, peripartum, inflammatory, hyperthyroidism, Takotsubo, and chronic illness-induced CMs. Our discussion also includes a review on their respective pathophysiology, as well as possible management solutions.