A single pathophysiological pathway in Takotsubo cardiomyopathy: Catecholaminergic stress

Reverse Takotsubo Cardiomyopathy Triggered by Undiagnosed Right Adrenal Pheochromocytoma: A Rare Occurrence

Takotsubo cardiomyopathy (TTC), also known as stress cardiomyopathy or broken heart syndrome, is a condition characterized by transient left ventricular dysfunction resembling myocardial infarction but without obstructive coronary artery disease. We present a rare case of a 59-year-old patient with cardiogenic shock (CS) caused by reverse TTC triggered by an undiagnosed right adrenal pheochromocytoma tumor. The patient initially presented with chronic headaches and difficulty breathing, and their condition rapidly deteriorated, necessitating intubation and inotropic support. Diagnostic tests confirmed the diagnosis of reverse TTC, and further investigation revealed an actively growing adrenal mass suggestive of a pheochromocytoma. The patient responded well to treatments, including the use of intra-aortic balloon pump support and subsequent weaning. A right adrenalectomy confirmed the presence of a pheochromocytoma. This case highlights the association between pheochromocytoma and reverse TTC, emphasizing the need to consider this rare etiology in patients presenting with CS. Long-term monitoring is crucial due to the risk of recurrence, even after tumor removal.

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.

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.

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.

Endocrine causes of heart failure: A clinical primer for cardiologists

Heart failure (HF) may be a presenting manifestation of a few endocrine disorders and should be considered in evaluation of heart failure causes. This clinically oriented review is an attempt to highlight the protean manifestations of heart failure in endocrine diseases which could present either as acute or chronic heart failure. Acute heart failure manifests as hypertensive crisis, Takotsubo syndrome, or as tachy/brady cardiomyopathies. Chronic heart failure could masquerade with features of hyperdynamic heart failure, or hypertrophic, restrictive or dilated cardiomyopathy. Rarely constrictive features or resistant heart failure could be the presenting feature. Isolated presentation as pulmonary hypertension and right heart failure are also documented. Good history-taking and physical examination with targeted investigations will help in the timely management for reversing the pathophysiology to a significant extent by appropriated management.

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.

Tako-tsubo Syndrome as First Manifestation in a Case of Pheochromocytoma Developed From a Non-functional Adrenal Incidentaloma

Background: Pheochromocytoma is a catecholamine secreting tumor that, in extremely rare cases, may develop over time from a non-functional adrenal adenoma. Catecholamine excess can lead to a kind of cardiomyopathy similar to that seen in tako-tsubo syndrome (TTS). Case report: A 69 years old female with a history of type 2 diabetes, hypertension, and a non-functional right adrenal adenoma diagnosed 3 years earlier was referred to our center for further investigations. During the evaluation, she had a hypertensive crisis with chest pain, tachycardia, and diaphoresis. Suspecting an acute coronary syndrome, she underwent coronary angiography, which showed the typical features of TTS. The high 24 h-urinary metanephrines excretion and abdominal MRI findings were suggestive of pheochromocytoma. Right laparoscopic adrenalectomy was performed, with the resolution of all symptoms. Pathology findings confirmed the diagnosis of pheochromocytoma. After 12 months, the patient was still asymptomatic, with the echocardiography displaying a complete recovery of the left-ventricular function. Conclusions: The development of a pheochromocytoma from an adrenal non functional adenoma is an extremely rare event, but potentially life-threating because of the catecholamine-associated cardiovascular toxicity. In particular, TTS is a form of cardiomyopathy that has been increasingly described as associated with catecholamine-secreting tumors. The exclusion of pheochromocytoma in a patient with TTS has important therapeutic implications, since the administration of β-blockers may be extremely harmful in patients with catecholamine surge in the absence of adequate α-blockage.

Reverse takotsubo cardiomyopathy- life-threatening symptom of an incidental pheochromocytoma: a case report

Background

Cardiogenic shock (CS) due to takotsubo cardiomyopathy (TTC) is a life-threatening condition. Therapy is challenging because of the ambivalent effects of catecholamines. Catecholamines are required to stabilize blood pressure but might aggravate TTC. Cardiac assist devices could be a suitable solution for conserving catecholamines and the prevention of TTC perpetuation.

Case summary

We report the case of a male patient with refractory CS and severe respiratory insufficiency as a result of a reverse TTC, which involved both ventricles. Simultaneous circulatory support with an Impella CP^® and veno-arterial extracorporeal membrane oxygenation was initiated for cardiopulmonary stabilization and catecholamine weaning. A giant, incidental pheochromocytoma was diagnosed as the cause of TTC. After drug treatment and resection of the tumour, biventricular function completely recovered within 7 weeks.

Discussion

A rare and challenging situation is the coincidence of a nor/epinephrine-secreting tumour, such as a pheochromocytoma, and severe CS complicating TTC. Although percutaneous left ventricular assist devices (pLVAD) are highly complicated and have shown conflicting results in terms of clinical efficacy for CS, its use may prevent the perpetuation of TTC due to reduced catecholamines requirement.

Variations in glucose/C-peptide ratio in patients with type 2 diabetes associated with renal function

INTRODUCTION

Accurate dosing of medications for glycemic control is a challenge for clinicians in diabetic patients with kidney disease. Diminishing glomerular filtration rates are associated with decreased renal clearance of insulin and increased prevalence of hypoglycemic episodes. Measurement of glucose/C peptide ratios may be useful to guide dosing in those patients who receive powerful insulin secretogogues as glomerular function decreases with age and disease.

METHODS

In order to determine the relationship between glucose, C-peptide and renal function, we reviewed the records of patients with type 2 diabetes followed in our kidney hypertension clinic who met the following criteria: age 35-90 years, requirement of medications to control glycemia, at least 4 simultaneous measurements of C peptide, HbA1c, creatinine and blood glucose.

RESULTS

87 patients (67 males, 20 females), ages 67.1 ± 10.6 years, BMI 32.5 ± 5.2, A1c 8.2 ± 1.2%, eGFR 73 ± 27.2 ml/min, had glucose/C-peptide ratios 60.7 ± 46.4. 59% of the total group were taking insulin secretogogues. Patients were divided into groups based upon mean eGFR and use or absence of insulin secretogogues. Glucose C-peptide ratios were lowest in the quartile of patients with the lowest eGFR (<50 ml/min).

CONCLUSION

Diminished renal function and advanced age are associated with the lowest glucose/C-peptide ratios, independent of achieved glycemic control. With similar use of secretogogues, glucose/C-peptide ratio were lower when eGFR was ≤49 ml/min compared to >50-80 ml/min. Use of secretogogues was associated with decreased glucose/C-peptide levels. In patients with reduced renal function (eGFR < 50 ml/min), use of insulin secretogogues may be associated with lower glucose/C-peptide ratios associated with higher risks for hypoglycemic reactions.

Brain functional connectivity is altered in patients with Takotsubo Syndrome

Takotsubo syndrome (TTS) is an acute, reversible cardiomyopathy. The central autonomic nervous system (ANS) is believed to play a role in this disease. The aim of the present study was to investigate the patterns of brain functional connectivity in a sample of patients who had experienced a previous episode of TTS. Brain functional connectivity, both at rest and in response to the stressful stimulus of topical cold stimulation, was explored using functional magnetic resonance imaging (fMRI), network-based statistics (NBS) and graph theory analysis (GTA) in a population consisting of eight patients with a previous episode of TTS and eight sex- and age-matched controls. At rest, a network characterized by increased connectivity in the TTS group compared to controls and comprising elements of the central ANS was identified. GTA revealed increased local efficiency, clustering and strength in regions of the bilateral hippocampus in subjects with a previous episode of TTS. When stressed by local exposure to cold, the TTS group differed significantly from both a pre-stress baseline interval and from the control group, showing increased connectivity in a network that included the left amygdala and the right insula. Based on the results, patients with TTS display a reorganization of cortical and subcortical networks, including areas associated with the emotional response and autonomic regulation. The findings tend to support the hypothesis that a deregulation of autonomic control at the central level plays a significant role in this syndrome.

Pheochromocytoma-related cardiomyopathy presenting as broken heart syndrome: Case report and literature review

•

This is a case report of a rare adrenal tumor that manifested as acute coronary syndrome.

•

Adrenalectomy for pheochromocytoma presents a risk for intraoperative hemodynamic instability.

•

Preoperative medical care is essential to reduce intraoperative complications.

•

This case exemplifies the importance of the various symptoms that are prevalent with excessive circulating adreno-receptor agents.

Introduction

Pheochromocytoma are neuroendocrine tumors that arise from sympathetic chromaffin cells within the adrenal medulla. They principally secrete catecholamines, potentially causing life-threatening cardiovascular complications. A myriad of symptomatology and clinical findings are associated with pheochromocytoma, including a catecholamine-induced dilated cardiomyopathy.

Presentation of case

A 50-year-old woman presented with retrosternal chest pain and underwent diagnostic evaluation for acute coronary syndrome. Cardiac catheterization demonstrated patent coronary arteries and a pattern of ventricular hypokinesis consistent with takotsubo cardiomyopathy, also known as broken heart syndrome. Further imaging with abdominal CT revealed an adrenal mass. Laboratory markers supported the clinical picture of pheochromocytoma. Right adrenalectomy was performed and our patient was symptom-free at discharge on post-operative day three.

Discussion

Alpha and beta adrenergic blockade are used in a critical care setting to prevent perioperative hemodynamic instability as well as catecholamine-induced heart failure in the setting of pheochromocytoma. Patients commonly require vasopressors in the postoperative period due to the rapid reduction in circulating catecholamines following resection. Discharge planning should include recommendations for genetic counseling to screen for syndromic causes of pheochromocytoma that increase the risk for other neoplasms.

Conclusion

We present a case report of a rare adrenal tumor in a middle-aged woman that manifested as acute coronary syndrome. A presumptive diagnosis of takotsubo cardiomyopathy on cardiac catheterization led to further investigation. Abdominal imaging located an adrenal mass that correlated with laboratory studies positive for high levels of catecholamines and their metabolites. The tumor was excised and the patient recovered without complications.

Mourning and Takotsubo cardiomyopathy: neuroendocrine implications and nutritional management

This article aims to make reference to some recent mourning aspects considered risk factors for cardiovascular disease, specifically the Takotsubo cardiomyopathy. The objective was to describe the stress from the death of a loved one combining it to the possibility of occurrence of Takotsubo cardiomyopathy through the perception of a traumatic event by the cortex, which triggers the subcortical brain circuit affecting the endocrine response. Given the growing acknowledgement of this cardiomyopathy, it is possible to contextualize the nutritional behaviours and decisions surrounding it, whose benefits must exceed the condition of temporary cardiac dysfunction and extend to food choices that have some influence in the limbic system. It is a descriptive analysis that aims to problematize the theme into reflections based on this experience, considering the foundation with the science of nutrition.

Funny Lumps, Flaming Pheo, and a Broken Heart: A Rare Case of Pheochromocytoma

Pheochromocytoma is the underlying etiology in 0.1% of hypertensive cases. However, it may be present in up to 5.7% of patients with neurofibromatosis I (NF1). The burst of catecholamines inherent in pheochromocytoma has significant effects on the mechanical and electrical activity of the myocardium. Different theories have been postulated for myocardial stunning in patients with pheochromocytoma that include microvascular spasm, impaired fatty acid metabolism, increased production of oxygen-derived free radicals and dynamic left ventricular mid-cavity obstruction. QT interval prolongation is seen in 16% to 35% of patients with pheochromocytoma. Takotsubo cardiomyopathy (TS) is now being increasingly identified and it may be responsible for up to 40% of cases of acute catecholamine cardiomyopathy. These manifestations may sometimes precede or cloud the typical triad of a headache, sweating, and tachycardia.

We herein present a case of a 42-year-old female with a unique combination of QT prolongation, torsades de pointes, and TS caused by pheochromocytoma in the background of NF1. All these complications are potentially reversible with the removal of the underlying adrenal tumor, underscoring the importance of a high suspicion for pheochromocytoma in patients with NF1.

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.

Copy number variants implicate cardiac function and development pathways in earthquake-induced stress cardiomyopathy

The pathophysiology of stress cardiomyopathy (SCM), also known as takotsubo syndrome, is poorly understood. SCM usually occurs sporadically, often in association with a stressful event, but clusters of cases are reported after major natural disasters. There is some evidence that this is a familial condition. We have examined three possible models for an underlying genetic predisposition to SCM. Our primary study cohort consists of 28 women who suffered SCM as a result of two devastating earthquakes that struck the city of Christchurch, New Zealand, in 2010 and 2011. To seek possible underlying genetic factors we carried out exome analysis, genotyping array analysis, and array comparative genomic hybridization on these subjects. The most striking finding was the observation of a markedly elevated rate of rare, heterogeneous copy number variants (CNV) of uncertain clinical significance (in 12/28 subjects). Several of these CNVs impacted on genes of cardiac relevance including RBFOX1, GPC5, KCNRG, CHODL, and GPBP1L1. There is no physical overlap between the CNVs, and the genes they impact do not appear to be functionally related. The recognition that SCM predisposition may be associated with a high rate of rare CNVs offers a novel perspective on this enigmatic condition.

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.

Hydrogen sulfide attenuates cardiac injury in takotsubo cardiomyopathy by alleviating oxidative stress

Takotsubo cardiomyopathy (TCM) is characterized by transient left ventricular apical ballooning with the absence of coronary occlusion, which is an acute cardiac syndrome with substantial morbidity and mortality. It was reported that reduced endogenous hydrogen sulfide (H₂S) levels may be related to various heart diseases. The present study investigated the mechanism by which H₂S administration modulates and protects cardiac function in TCM rats. In order to establish a TCM model, Sprague Dawley (SD) rats were injected with a single dose of β-adrenergic agonist isoprenaline (ISO). We found that ISO induced cardiac dysfunction, which was characterized by a significant decrease in left ventricular systolic pressure (LVSP), maximum contraction velocity (+dp/dtmax), maximum relaxation velocity (-dp/dtmax) and increased left ventricular end-diastolic pressure (LVEDP). Accordingly, we found that plasma and heart tissue H₂S levels in TCM rats decreased significantly, and cardiac cystathionine γ-lyase (CSE) and 3-mercaptopyruvate sulfurtransferase (3-MST) expression were lower. Moreover, cardiac dysfunction in TCM was associated with oxidative stress response and reactive oxygen species (ROS) formation. NADPH Oxidase 4 (NOX₄) and p67 protein expressions significantly increased in TCM cardiac tissues. In addition, Sodium hydrosulfide (NaHS) ameliorated ISO-induced cardiac dysfunction and reversed ISO-induced oxidative stress. This study revealed that H₂S exerted cardioprotective effects by reducing NADPH oxidase, which reduced ROS formation and prevented oxidative stress. Our study provided novel evidence that H₂S is protective in myocardial dysfunction in TCM rats and could be a therapeutic target for alleviating β-adrenergic system overstimulation-induced cardiovascular dysfunction.

Pheochromocytoma and stress cardiomyopathy: Insight into pathogenesis

AIM

To investigate the occurrence of cardiomyopathy (CMP) in a cohort of patients with histologically proven pheochromocytoma (pheo), and to determine if catecholamine excess was causative of the left ventricular (LV) dysfunction.

METHODS

A retrospective chart review spanning years 1998 through 2014 was undertaken and patients with a diagnosis of pheo confirmed with histopathologic examination were included. Presenting electrocardiograms and cardiac imaging studies were reviewed. Transthoracic echocardiography (TTE), ventriculography or single positron emission computed tomography imaging was evaluated and if significant abnormalities [left ventricular hypertrophy (LVH) or LV dysfunction] were noted in the pre operative period a follow up post-operative study was also analyzed. Multivariate analysis using logistic regression was used to investigate independent predictors for outcomes of interest, LV dysfunction and LVH.

RESULTS

We identified 18 patients with diagnosis of pheo confirmed on pathology. Mean age was 54.3 ± 19.3 years and 11 (61.1%) patients were females. 50% of such patients had either resistant hypertension or labile blood pressures during hospitalization, which had raised suspicion for a pheo. Cardiac imaging studies were available for 12 (66.7%) patients at the time of inclusion into study and preceding the adrenalectomy. 7 (58.3%) patients with a TTE available for review had mild or more severe LVH while 3 (25%) patients had LV dysfunction of presumably acute onset. In a multivariate analysis, elevated catecholamine levels as assessed by urinary excretion of metabolites was not an independent predictor of development of LV systolic dysfunction or of presence of LVH on TTE. Two female patients with a preceding history of hypertension had marked LV hypertrophy and systolic anterior motion of the mitral valve. Prolongation of the QTc interval was noted in 5 (27.8%) patients but no acute arrhythmias were observed in any patient.

CONCLUSION

This study adds to the growing body of literature on the predilection of patients with pheochromocytomas to develop non-ischemic CMP. Degree of catecholamine excess as measured by urinary secretion of metabolites did not predict the development of CMP but 2 of 3 patients developed CMP in the setting of significant acute physiologic stress. Our findings provide support to the proposed etiologic role of elevated catecholamines in TC and other stress induced forms of CMP, however, activation of a brain-neural-cardiac axis from acute stress and local release of catecholamines but not chronic catecholamine elevations are likely to be responsible in pheo related CMP.

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.

Contemporary review on the pathogenesis of takotsubo syndrome: The heart shedding tears: Norepinephrine churn and foam at the cardiac sympathetic nerve terminals

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.

Acute and Chronic Pheochromocytoma-Induced Cardiomyopathies: Different Prognoses?: A Systematic Analytical Review

Pheochromocytoma and paraganglioma (PPG) are rare and late-diagnosed catecholamine secreting tumors, which may be associated with unrecognized and/or severe cardiomyopathies. We performed a computer-assisted systematic search of the electronic Medline databases using the MESH terms "myocarditis," "myocardial infarction," "Takotsubo," "stress cardiomyopathy," "cardiogenic shock", or "dilated cardiomyopathy," and "pheochromocytoma" or "paraganglioma" from 1961 to August 2012. All detailed case reports of cardiomyopathy due to a PPG, without coronary stenosis, and revealed by acute symptoms were included and analyzed. A total of 145 cases reports were collected (49 Takotsubo Cardiomyopathies [TTC] and 96 other Catecholamine Cardiomyopathies [CC]). At initial presentation, prevalence of high blood pressure (87.7%), chest pain (49.0%), headaches (47.6%), palpitations (46.9%), sweating (39.3%), and shock (51.0%) were comparable between CC and TTC. Acute pulmonary edema (58.3% vs 38.8%, P = 0.03) was more frequent in CC. There was no difference in proportion of patients with severe left ventricular systolic dysfunction (LV Ejection Fraction [LVEF] < 30%) at initial presentation between both groups (P = 0.15). LVEF recovery before (64.9% vs 40.8%, P = 0.005) and after surgical resection (97.7% vs 73.3%, P = 0.001) was higher in the TTC group. Death occurred in 11 cases (7.6%). In multivariate analysis, only TTC was associated with a better LV recovery (0.15 [0.03-0.67], P = 0.03). Pheochromocytoma and paraganglioma can lead to different cardiomyopathies with the same brutal and life-threatening initial clinical presentation but with a different recovery rate. Diagnosis of unexplained dilated cardiomyopathy or TTC should lead clinicians to a specific search for PPG.

Rare Variants in Cardiomyopathy Genes Associated With Stress-Induced Cardiomyopathy

BACKGROUND

Stress-induced cardiomyopathy (SIC) is a poorly understood condition associated with periods of emotional and physical stress. The clinical approaches for management of SIC are supportive and reactive to patient symptoms.

OBJECTIVE

To utilize next-generation exome sequencing to define genetic variation associated with, and potentially responsible for, this disease.

METHODS

We performed exome sequencing of 7 white female patients with SIC. Filtering of the identified variants was performed to limit our investigation to those sequences that passed quality control criteria, were rare or novel, were determined algorithmically to have high impact on the associated protein, and were within regions of high species conservation. All variants were verified by using Sanger sequencing.

RESULTS

Exome-sequencing analysis revealed that each patient carried predicted deleterious variants affecting known cardiomyopathy genes. In each case, the identified variant was either not previously found in public human genome data or was previously annotated in a database of clinical variants associated with cardiac dysfunction.

CONCLUSION

Patients with SIC harbor deleterious mutations in established cardiomyopathy genes at a level higher than healthy controls. We hypothesize that patients at highest risk for SIC likely live in a compensated state of cardiac dysfunction that manifests clinically only after the myocardium is stressed. In short, we propose that SIC is another example of an occult cardiomyopathy with a distinct physiological trigger and suggest that alternative clinical approaches to these patients may be warranted.

ABBREVIATIONS

CADD, Combined Annotation Dependent DepletionFPKM, fragments per kilobase pair of exon per million fragments mappedNHLBI GO ESP, National Heart, Lung, and Blood Institute Grand Opportunity Exome Sequencing ProjectPCR, polymerase chain reactionSIC, stress-induced cardiomyopathy.

Takotsubo Cardiomyopathy: A Long Term Follow-up Shows Benefit with Risk Factor Reduction

Only sparse data was available on long-term of Takotusbo Cardiomyopathy (TC). Previous studies suggested prognosis is not necessarily benign. We report the long-term follow-up of 12 TC patients actively managed with risk factor reduction. Retrospective analysis of all patients diagnosed with TC at our hospital between 1998 and 2010. We identified 12 patients with TC among 1651 cases of emergent left heart catheterization over 12 years. Mean follow-up time was 8.3 ± 3.6 years. All were female, 87% had hypertension, 25% had history of Coronary Artery Disease (CAD), 67% had hyperlipidemia, 44% had some preceding emotional trauma, and 44% had some physical/physiological stress. Previous studies have shown that over 50% of TC patients experience future cardiac events, and 10% have a recurrence of TC. Patients were prescribed therapeutic lifestyle changes (TLC) and guideline directed medical therapy (GDMT) for aggressive risk factor reduction. TLC included diet, exercise, and cardiac rehabilitation. GDMT often included aspirin, beta-blockers, ACE-inhibitors, and statins. Follow-up echocardiograms showed recovery and maintenance of the ejection fraction. There was no cardiac mortality and no recurrences of TC. Aggressive risk factor reduction with TLC and GDMT may be effective in improving the long term outcomes of patients with TC.