Insights into the pathogenesis of takotsubo syndrome, which with persuasive reasons should be regarded as an acute cardiac sympathetic disease entity

Update of Takotsubo cardiomyopathy: Present experience and outlook for the future

Takotsubo cardiomyopathy (TTS) has become a recognised clinical entity since the Japanese scientist Sato first described it in 1990.

Despite an increasing number of confirmed cases, especially during the COVID-19 pandemic, its pathophysiology remains incompletely understood, and decision-making differs in the diagnosis and treatment. In addition, it is not evident whether a significant increase in TTS is due to better understanding among practitioners and widespread access to coronary angiography, or if it is a reflection of an actual increase in incidence.

We analysed a series of international research studies from 1990 to 2021. Beyond epidemiology and clinical presentation, we evaluated and summarised fundamental knowledge about various predisposing factors, with particular attention to the iatrogenic impact of certain drugs, namely antidepressants, chemotherapy, and antiarrhythmics.

Furthermore, we highlighted the main pathophysiological theories to date. In addition, based on published studies and clinical cases, we investigated the role of numerous diagnostic approaches in the differential diagnosis of TTS and identified predictors of TTS complications, such as cardiogenic shock, ventricular fibrillation, and left ventricular thrombi. Accordingly, we sought to propose a diagnostic algorithm and further treatment management of TTS under the presence of possible complications to help practitioners make more informed decisions, as the initial presentation continues to pose a challenge due to its close similarity to acute coronary syndrome with ST-elevation.

In conclusion, this article examines Takotsubo cardiomyopathy from different perspectives and, along with future systematic reviews and meta-analyses, can be of particular interest to practising cardiologists and researchers in developing clinical guidelines.

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.

Coronary microvascular dysfunction in Takotsubo syndrome: cause or consequence

Takotsubo syndrome (TS) is an acute cardiac disease entity, characterized by a transient myocardial stunning in a distinctive predominantly regional circumferential pattern. One of the discussed pathological mechanisms of TS is coronary ischemia including coronary microvascular dysfunction (CMVD). Many studies have revealed invasive or non-invasive signs of CMVD in patients with TS, and therefore some investigators believe that CMVD is the primary cause of TS. Nevertheless, other studies have not shown any sign of CMVD. In addition, those studies, which have shown signs of CMVD, do not reveal such signs in all the three coronary vessel distribution; some of the patients show signs of CMVD in two or only one coronary artery territory. Moreover, signs of CMVD in TS are more prevalent and more pronounced in the left anterior descending artery (LAD) distribution. The CMVD in TS is reversible in a pattern parallel to the improvement of myocardial wall motion abnormality. In this review, substantial evidences challenging CMVD as the primary cause of TS and supporting the concept that CMVD is a secondary or epiphenomenon in TS are provided. Furthermore, convincing explanation is given for the causes of the more prevalent and the more pronounced signs of CMVD observed in the LAD distribution.

Current Knowledge and Future Challenges in Takotsubo Syndrome: Part 1-Pathophysiology and Diagnosis

First recognized in 1990, takotsubo syndrome (TTS) constitutes an acute cardiac condition that mimics acute myocardial infarction commonly in the absence of obstructive coronary artery disease; it is characterized by temporary left ventricular dysfunction, regularly in a circumferential apical, midventricular, or basal distribution. Considering its acute clinical presentation, coronary angiography with left ventriculography constitutes the gold standard diagnostic tool to exclude or confirm TTS. Frequently, TTS is related to severe emotional or physical stress and a subsequent increased adrenergic stimulation affecting cardiac function. Beyond clinical presentation, epidemiology, and novel diagnostic biomarkers, this review draws attention to potential pathophysiological mechanisms for the observed reversible myocardial dysfunction such as sympathetic overdrive-mediated multi-vessel epicardial spasms, microvascular dysfunction, the direct toxicity of catecholamines, lipotoxicity, and inflammation. Considering the long-term prognosis, further experimental and clinical research is indispensable to elucidate further pathophysiological mechanisms underlying TTS before randomized control trials with evidence-based therapeutic management can be performed.

Cardiovascular Manifestations and Complications of Pheochromocytomas and Paragangliomas

Pheochromocytomas and paragangliomas (PPGLs) are rare neuro-endocrine tumors. The catecholamine surge causes paroxysmal or chronic secondary hypertension. PPGLs may present as hypertensive- or PPGL-crisis with severe life-threatening cardiac and cerebrovascular complications. PPGLs-induced cardiac manifestations have been reported with diagnoses as PPGLs-induced electrocardiogram (ECG) changes “mimicking acute myocardial infarction”, arrhythmias, myocarditis, acute coronary syndrome, dilated cardiomyopathy, and lately as takotsubo syndrome. Critical analysis of these reports reveals that most of these cardiac manifestations have certain features in common. They have a dramatic clinical presentation and are reversible if the disease is treated with appropriate medical therapy and surgical resection of the PPGL tumor. They may have the same repolarization ECG changes irrespective of the clinical cardiac diagnosis, usually associated with mild to moderate elevations of myocardial biomarkers as troponins and normal coronary arteries. The histopathological findings are usually focal or multifocal in the form hypercontracted sarcomeres and contraction band necrosis (myofibrillar degeneration) with subsequent secondary mononuclear cell infiltration. Evidences argue the PPGL caused surge of catecholamines triggers hyperactivation of the sympathetic nervous system with cardiac sympathetic nerve terminal disruption with norepinephrine spillover causing the cardiac complications. A comprehensive review of various reported cardiovascular manifestations and complications of PPGLs are presented.

Autonomic neurocardiogenic syndrome is stonewalled by the universal definition of myocardial infarction

Myocardial infarction (MI) is defined as myocardial cell death due to prolonged myocardial ischemia. Clinically, troponin rise and/or fall have become the “defining feature of MI” according to the universal definition of MI (UD-MI). Takotsubo syndrome (TS) and TS-related disease conditions also cause troponin elevation with typical rise and/or fall pattern but through a mechanism other than coronary ischemia. By strict application of the clinical diagnostic criteria for type-1 MI, type-2 MI, type-3 MI, and MI with non-obstructive coronary arteries according to the UD-MI including the fourth one published recently, TS and most of the 26 other causes of troponin elevation mentioned in the fourth UD-MI may erroneously be classified as MI. The existing evidence argues for the case that TS by itself is not a MI. Hyper-activation of the autonomic-sympathetic nervous system including local cardiac sympathetic hyper-activation and disruption with nor-epinephrine churn and spillover is the most probable cause of TS. This autonomic neuro-cardiogenic (ANCA) mechanism results in myocardial “cramp” (stunning), the severity and duration of which depend on the degree of the sympathetic-hyperactivation and nor-epinephrine spillover. The myocardial cramp may squeeze the cytosolic free troponin pools causing mild to moderate troponin elevation in TS and TS-related disease conditions. This ANCA syndrome, which has hitherto been enveloped by the UD-MI over more than one decade, may occur in acute, recurrent, and chronic forms. In this critical review, the controversies of UD-MI, evidence for ANCA syndrome, and a hypothetical mechanism for the troponin elevation in ANCA syndrome are provided.

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.

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.

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, repetitive and chronic Takotsubo syndrome in patients with chronic kidney disease: Sympathetic reno-cardial syndrome

Heart failure and cardiovascular death are common in patients with chronic kidney disease (CKD) and extremely prevalent in patients undergoing dialysis. It has been shown that the excess of cardiovascular mortality in this patient population is not fully accounted for by the traditional cardiovascular risk factors. Substantial evidence exists for the presence of sympathetic over-activity in patients with dialytic and non-dialytic CKD. Several studies have also been reported on reversible segmental left ventricular wall motion abnormality consistent with myocardial stunning in association with dialysis especially hemodialysis. In the literature, the most acceptable underpinning hypothesis for the myocardial stunning in CKD is "demand myocardial ischemia". However, the occurrence of cardiac sympathetic over-activation-disruption and repeated reversible myocardial stunning in patients with CKD can be compared to that occurring in acute Takotsubo syndrome where local cardiac sympathetic disruption may cause acute regional circumferential pattern of myocardial stunning. In this manuscript, converging evidences suggestive for the fact that acute, repetitive, and chronic TS may be one of the important causes of cardiac morbidity including myocardial stunning and heart failure and mortality in patients with CKD are provided.

The Use of Fluoxetine in a Patient With Takotsubo Cardiomyopathy

Takotsubo cardiomyopathy is an acute coronary syndrome that is believed to be brought on by stress. Symptoms, which are similar to an acute myocardial infarction, include chest pain, shortness of breath, arrhythmias, and cardiogenic shock, and the electrocardiogram often shows ST and T wave changes. Left ventricular wall hypokinesis along with a significantly reduced ejection fraction are seen on echocardiogram. The great majority of these symptoms all occur in the absence of occlusive disease. Many cases have been reported in which the development of takotsubo cardiomyopathy was associated with serotonin norepinephrine reuptake inhibitors and tricyclic antidepressants. However, no cases of takotsubo cardiomyopathy have been reported involving selective serotonin reuptake inhibitors. This article presents the case of a 51-year-old woman receiving stable therapy with fluoxetine who developed takotsubo cardiomyopathy after an acute stress. We also discuss the clinical presentation of takotsubo cardiomyopathy, review possible causes, and discuss the treatment of depressive symptoms in patients who are at increased risk of developing this illness.

The pathogenesis of reversible T-wave inversions or large upright peaked T-waves: Sympathetic T-waves

Reversible electrocardiographic (ECG) repolarization changes including T-wave inversions (TWI), large upright peaked T-waves (LUPTW) and prolongation of the corrected QT interval (P-QTc) have been reported in association with myriads of acute cardiac and non-cardiac diseases. Through the last 70 years, the TWIs have been described under different terms as; cerebral, giant, global, canyon, Wellens or coronary and cardiac memory T waves. During the last 15 years, the reversible TWI and LUPTW in association with P-QTc have been described as characteristic ECG features in takotsubo syndrome (TS), which also may be triggered by the same aforementioned acute cardiac and non-cardiac disease entities. The pathogenesis of these reversible T-wave changes is not clear-cut. In this manuscript, substantial evidences for a causal link between the local cardiac sympathetic disruption and the development of the reversible TWI and LUPTW are presented. As a result, a pathogenetic term for the reversible TWI or LUPTW, which is sympathetic T waves (sympathetic TWI or sympathetic LUPTW), would be the most appropriate term.

Broken Heart Syndrome: A Typical Case

This case describes a combination external treatment for “Broken Heart Syndrome” that includes a lavender footbath, massage using moor extract, and oxalis ointment to the abdomen applied by an Anthroposophic nurse for a specific personality type. Lavender footbaths have been used since ancient times for relaxation and calming, while moor extract has been used medicinally in Europe since the middle ages for warmth and environmental protection. Rhythmical massage using moor extract and oxalis ointment poultice to the abdomen are part of the tradition of Anthroposophic nursing when managing stress induced by emotional and physical trauma. An elderly lady with specific characteristics diagnosed as Broken Heart Syndrome received one treatment a week for 4 weeks given by an Anthroposophic nurse at an integrative medical center. Between treatments, education was given to enable self-treatment in the home. The nursing treatments, each using lavender footbaths, moor extract massage, and oxalis ointment poultice to the abdomen, proved very effect, and no negative effects were reported. External applications need to be considered by nurses caring for specific personality types with Broken Heart Syndrome.

The harmful effects of subarachnoid hemorrhage on extracerebral organs

Subarachnoid hemorrhage (SAH) is a devastating neurological disorder. Patients with aneurysmal SAH develop secondary complications that are important causes of morbidity and mortality. Aside from secondary neurological injuries, SAH has been associated with nonneurologic medical complications, such as neurocardiogenic injury, neurogenic pulmonary edema, hyperglycemia, and electrolyte imbalance, of which cardiac and pulmonary complications are most common. The related mechanisms include activation of the sympathetic nervous system, release of catecholamines and other hormones, and inflammatory responses. Extracerebral complications are directly related to the severity of SAH-induced brain injury and indicate the clinical outcome in patients. This review provides an overview of the extracerebral complications after SAH. We also aim to describe the manifestations, underlying mechanisms, and the effects of those extracerebral complications on outcome following SAH.

Sepsis-induced myocardial depression and takotsubo syndrome

Abstract Background and objectives: Myocardial depression in the setting of sepsis and septic shock is common and has been recognized for a long time. The aim of this study is to find out an association and causal link between sepsis and takotsubo syndrome (TS).

METHODS

Fifteen cases of TS were studied. Critical review of the literature dealing with sepsis and myocardial depression was done Results: Fifteen cases of sepsis-induced TS are described. Fifty-three per cent of the patients were men. The ages ranged from 39 to 76 years (mean age 60 years). Two-thirds of the patients had ST-elevation myocardial infarction ECG changes. Complications occurred in 80% of the patients. No specific types of sepsis or micro-organisms were associated with the development of TS. Critical review of the sepsis-induced myocardial depression shows that the left ventricular dysfunction, which is reversible within one-to-two weeks, is characterized by segmental ventricular dysfunction, and involvement of the right ventricle in one fourth of cases. These features are also consistent with TS.

CONCLUSIONS

Sepsis triggers TS, which may be the cause of the majority of cases of sepsis-induced myocardial depression. Acute cardiac sympathetic disruption with noradrenaline spill-over may be the cause of sepsis-induced TS.

Acute cardiac sympathetic disruption in the pathogenesis of the takotsubo syndrome: a systematic review of the literature to date

Takotsubo syndrome (TS), also known as broken heart syndrome and neurogenic stunned myocardium, is an acute cardiac disease entity characterized by a clinical picture mimicking that of an acute coronary syndrome. The pathogenesis of TS has not been established yet. Among the most often debated pathologic mechanisms of TS are as follows: first, multi-vessel coronary spasm; second, myocardial microvascular dysfunction; third, aborted myocardial infarction caused by transient thrombotic occlusion of a long wrap-around left anterior descending artery; fourth, left ventricular outflow tract obstruction; fifth, blood-borne catecholamine cardiac toxicity; and sixth, cardiac sympathetic disruption and norepinephrine seethe and spillover. The aim of this review is to provide a thorough analysis of the literature data coming mainly from the neurological literature and dealing with the pathogenesis of TS. Substantial evidence challenging the first five hypotheses and arguing in favor of the hypothesis that acute cardiac sympathetic eruption and norepinephrine seethe and spillover is causing TS in predisposed patients is presented.