Acute impairment of regional myocardial glucose uptake in the apical ballooning (takotsubo) syndrome

Broken Heart Syndrome: Evolving Molecular Mechanisms and Principles of Management

Broken Heart Syndrome, also known as Takotsubo Syndrome (TS), is sudden and transient dysfunction of the left and/or right ventricle which often mimics Acute Coronary Syndrome (ACS). Japan was the first country to describe this syndrome in the 1990s, and since then it has received a lot of attention from researchers all around the world. Although TS was once thought to be a harmless condition, recent evidence suggests that it may be linked to serious complications and mortality on par with Acute Coronary Syndrome (ACS). The understanding of TS has evolved over the past few years. However, its exact etiology is still poorly understood. It can be classified into two main types: Primary and Secondary TS. Primary TS occurs when the symptoms of myocardial damage, which is typically preceded by emotional stress, are the reason for hospitalization. Secondary TS is seen in patients hospitalized for some other medical, surgical, obstetric, anesthetic, or psychiatric conditions, and the dysfunction develops as a secondary complication due to the activation of the sympathetic nervous system and the release of catecholamines. The etiopathogenesis is now proposed to include adrenergic hormones/stress, decreased estrogen levels, altered microcirculation, endothelial dysfunction, altered inflammatory response via cardiac macrophages, and disturbances in the brain-heart axis. The role of genetics in disease progression is becoming the focus of several upcoming studies. This review focuses on potential pathophysiological mechanisms for reversible myocardial dysfunction observed in TS, and comprehensively describes its epidemiology, clinical presentation, novel diagnostic biomarkers, and evolving principles of management. We advocate for more research into molecular mechanisms and promote the application of current evidence for precise individualized treatment.

Manganese-Enhanced Magnetic Resonance Imaging in Takotsubo Syndrome

BACKGROUND

Takotsubo syndrome is an acute cardiac emergency characterized by transient left ventricular systolic dysfunction typically following a stressful event. Despite its rapidly rising incidence, its pathophysiology remains poorly understood. Takotsubo syndrome may pass unrecognized, especially if timely diagnostic imaging is not performed. Defective myocardial calcium homeostasis is a central cause of contractile dysfunction and has not been explored in takotsubo syndrome. We aimed to investigate myocardial calcium handling using manganese-enhanced magnetic resonance imaging during the acute and recovery phases of takotsubo syndrome.

METHODS

Twenty patients with takotsubo syndrome (63±12 years of age; 90% female) and 20 volunteers matched on age, sex, and cardiovascular risk factors (59±11 years of age; 70% female) were recruited from the Edinburgh Heart Centre between March 2020 and October 2021. Patients underwent gadolinium and manganese-enhanced magnetic resonance imaging during index hospitalization with repeat manganese-enhanced magnetic resonance imaging performed after at least 3 months.

RESULTS

Compared with matched control volunteers, patients had a reduced left ventricular ejection fraction (51±11 versus 67±8%; P<0.001), increased left ventricular mass (86±11 versus 57±14 g/m2; P<0.001), and, in affected myocardial segments, elevated native T1 (1358±49 versus 1211±28 ms; P<0.001) and T2 (60±7 versus 38±3 ms; P<0.0001) values at their index presentation. During manganese-enhanced imaging, kinetic modeling demonstrated a substantial reduction in myocardial manganese uptake (5.1±0.5 versus 8.2±1.1 mL/[100 g of tissue ·min], respectively; P<0.0001), consistent with markedly abnormal myocardial calcium handling. After recovery, left ejection fraction, left ventricular mass, and T2 values were comparable with those of matched control volunteers. Despite this, native and postmanganese T1 and myocardial manganese uptake remained abnormal compared with matched control volunteers (6.6±0.5 versus 8.2±1.1 mL/[100 g of tissue ·min]; P<0.0001).

CONCLUSIONS

In patients with takotsubo syndrome, there is a profound perturbation of myocardial manganese uptake, which is most marked in the acute phase but persists for at least 3 months despite apparent restoration of normal left ventricular ejection fraction and resolution of myocardial edema, suggesting abnormal myocardial calcium handling may be implicated in the pathophysiology of takotsubo syndrome. Manganese-enhanced magnetic resonance imaging has major potential to assist in the diagnosis, characterization, and risk stratification of patients with takotsubo syndrome.

REGISTRATION

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CLINICALTRIALS

gov; Unique identifier: NCT04623788.

A Review of Nuclear Imaging in Takotsubo Cardiomyopathy

Takotsubo cardiomyopathy or Takotsubo Syndrome (TTS) is a reversible left ventricular dysfunction syndrome that is increasingly being recognized. Recent advances in nuclear imaging have allowed us to study TTS in greater detail. We searched the PubMed and Medline databases and identified 53 publications with 221 patients reporting nuclear imaging findings in TTS. The age of the patients ranged from 17 to 87 years and were predominantly women (88.2%). The TTS variant was apical (typical) in 170 (76.9%), mid-ventricular in 23 (10.4%), and basal (reverse TTS) in 2 (0.9%). Cardiac perfusion was assessed using ^99mTc sestamibi (MIBI) SPECT, ^99mTc tetrofosmin SPECT, ²⁰¹Tl SPECT, ⁸²Rb PET, ²⁰¹Tl SPECT, and ¹³N ammonia PET. Additional studies used were ¹²³I MIBG SPECT, ¹²³I BMIPP SPECT, ¹⁸F FDG PET, ⁶⁷Ga citrate, and ¹¹C hydroxy-ephedrine. A perfusion defect was seen in 69 (31.2%), and an inverse perfusion–metabolism mismatch (normal or near-normal perfusion with absent myocardial metabolic activity) was seen in 183 (82.8%) patients. Nuclear imaging has a significant role in evaluating, diagnosing, and prognosticating patients with TTS. As nuclear imaging technology evolves, we will surely gain more insights into this fascinating disorder.

Novel Imaging and Genetic Risk Markers in Takotsubo Syndrome

Takotsubo syndrome (TTS) is an increasingly recognized condition burdened by significant acute and long-term adverse events. The availability of novel techniques expanded the knowledge on TTS and allowed a more accurate risk-stratification, potentially guiding clinical management. The present review aims to summarize the recent advances in TTS prognostic evaluation with a specific focus on novel imaging and genetic markers. Parametric deformation analysis by speckle-tracking echocardiography, as well as tissue characterization by cardiac magnetic resonance imaging T1 and T2 mapping techniques, currently appear the most clinically valuable applications. Notwithstanding, computed tomography and nuclear imaging studies provided limited but promising data. A genetic predisposition to TTS has been hypothesized, though available evidence is still not sufficient. Although a genetic predisposition appears likely, further studies are needed to fully characterize the genetic background of TTS, in order to identify genetic markers that could assist in predicting disease recurrences and help in familial screening.

Takotsubo Cardiomyopathy: A Brief Review

Takotsubo cardiomyopathy is a reversible cardiomyopathy with a unique morphological feature of the left ventricle characterized by an apical ballooning appearance known for approximately known 25 years. Catecholamine drive plays an essential role in the pathogenesis and pathophysiology of Takotsubo cardiomyopathy; hence, it is also called stress cardiomyopathy. Physical stress could also have an impact and leads to a greater variety of characteristics in Takotsubo cardiomyopathy.

Supportive and symptomatic medication remains the mainstay therapy with priority to improving the function of the left ventricle for several days and full recovery in 3-4 weeks. Due to its similarity with myocardial infarction, Takotsubo cardiomyopathy requires careful diagnosis and management for the best possible outcome.

Pain-induced peripheral artery tonometry scores in the control arm are impaired in patients with apical ballooning syndrome

Mental and physical stress is thought to play an important causative factor in apical ballooning syndrome (ABS) likely secondary to the vasomotor dysfunction. However, there are currently few data related to the impact of physical stress in this unique cardiomyopathy.A total 18 patients, including 8 females with history of ABS and 10 post-menopausal controls, underwent physical and mental tests. Assessments included the pain-induced peripheral artery tonometry scores (PIPATs) and mental stress peripheral artery tonometry scores (PATs).Compared with control group, PIPATs were significantly attenuated in patients with ABS in both baseline and post-mental stress (0.94 ± 0.08 vs1.30 ± 0.54, P <.05 and 0.87 ± 0.19 vs1.24 ± 0.21 P = .01, respectively); mental stress PATs were significantly lower in patients with ABS, both in Stroop test (0.79 ± 0.30 vs 1.24 ± 0.43, P = .01) and arithmetic test (0.91 ± 0.27 vs 1.36 ± 0.57, P = .01). PIPATs correlated significantly with mental stress PATs, both in arithmetic and Stroop test (P <.05).The PIPATs were attenuated in female with history of ABS and the vascular response to pain may provide a different pathogenesis mechanism on detecting patients with ABS.

Cough-Induced Takotsubo (Stress) Cardiomyopathy

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This case demonstrates cough as an extremely rare but notable cause of TC.

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Plausible mechanisms include catecholamine surge, impaired cardiac microvascular and metabolic function, and extreme haemodynamic stress during cough.

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Cough should be considered as a potential aetiology in differential diagnosis of TC.

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There could be severe as well as subclinical cases of cough induced TC that goes unidentified.

Takotsubo cardiomyopathy: FDG myocardial uptake pattern in fasting patients. Comparison of PET/CT, SPECT, and ECHO results

BACKGROUND

The aim of this study was to assess the accumulation pattern of 18F-FDG in fasting patients with takotsubo cardiomyopathy (TTC) and to correlate the results with perfusion scintigraphy and echocardiography.

METHODS

18 consecutive patients with TTC were identified by clinical symptoms, cardiac catheterization, and echocardiography. Coronary angiography (CA) and transthoracic echocardiography (TTE) were performed on the day of the onset of symptoms. An assessment of myocardial perfusion (99mTc-MIBI) and glucose metabolism (18F-FDG) was performed within 18 days.

RESULTS

SPECT showed no regional perfusion abnormalities in 10/18 patients, and a mild perfusion defect was found in 8/18 patients. Perfusion abnormalities were limited to apical and para-apical regions. In 8/18 cases, there was an increased selective apical 18F-FDG accumulation. In 10/18 cases, in spite of the fastened 18F-FDG protocol, slightly inhomogeneous 18F-FDG uptake was present in the entire myocardium: with relatively reduced uptake of 18F-FDG in the apical region and LV mid-segments.

CONCLUSION

This study demonstrated the heterogeneous nature of myocardial 18F-FDG accumulation in patients with TTC. Selective, preferential apical 18F-FDG uptake in almost half of the patients confirms an existing disorder of glucose metabolism, similar to that observed in stunned or hibernated myocardium.

Pathophysiology of Takotsubo Syndrome

Originally described by Japanese authors in the 1990s, Takotsubo syndrome (TTS) generally presents as an acute myocardial infarction characterized by severe left ventricular dysfunction. TTS, however, differs from an acute coronary syndrome because patients have generally a normal coronary angiogram and left ventricular dysfunction, which extends beyond the territory subtended by a single coronary artery and recovers within days or weeks. The prognosis was initially thought to be benign, but subsequent studies have demonstrated that both short-term mortality and long-term mortality are higher than previously recognized. Indeed, mortality reported during the acute phase in hospitalized patients is ≈4% to 5%, a figure comparable to that of ST-segment-elevation myocardial infarction in the era of primary percutaneous coronary interventions. Despite extensive research, the cause and pathogenesis of TTS remain incompletely understood. The aim of the present review is to discuss the pathophysiology of TTS with particular emphasis on the role of the central and autonomic nervous systems. Different emotional or psychological stressors have been identified to precede the onset of TTS. The anatomic structures that mediate the stress response are found in both the central and autonomic nervous systems. Acute stressors induce brain activation, increasing bioavailability of cortisol and catecholamine. Both circulating epinephrine and norepinephrine released from adrenal medullary chromaffin cells and norepinephrine released locally from sympathetic nerve terminals are significantly increased in the acute phase of TTS. This catecholamine surge leads, through multiple mechanisms, that is, direct catecholamine toxicity, adrenoceptor-mediated damage, epicardial and microvascular coronary vasoconstriction and/or spasm, and increased cardiac workload, to myocardial damage, which has a functional counterpart of transient apical left ventricular ballooning. The relative preponderance among postmenopausal women suggests that estrogen deprivation may play a facilitating role, probably mediated by endothelial dysfunction. Despite the substantial improvement in our understanding of the pathophysiology of TTS, a number of knowledge gaps remain.

Broken heart, tako-tsubo or stress cardiomyopathy? Metaphors, meanings and their medical impact

The cardiac impact of psychological stress historically and socially understood as boundary experiences of human life has long since become an icon. From the aching heart to the sudden death provoked by awe, horror, grief, anger, and humiliation on one side and extreme enchantment, enthusiasm, and excitement on the other, the broken heart has become a globally recognized and powerful metaphor present from folklore to popular culture to high literature and back to everyday communication. In medicine, the "broken heart syndrome" is described as a relatively new nosological entity that has been used synonymously with the term tako-tsubo or stress cardiomyopathy. Among those three terms, however, the broken heart most vividly draws the connection between conditions under which lived experience triggers cardiac damage and conversely, cardiovascular death occurs. According to Hassan and Yamasaki (2013) [1] and quite apart from the general perception medical notions of the broken heart indeed go back to at least 1967, when Rees and Lutkins studied the death rate among 903 relatives of patients who died in Wales. They found that 4.8% of bereaved close relatives died within a year of bereavement compared with 0.68% of a non-bereaved control group. Among widows and widowers, the mortality rate was even 10 times greater than that of the matched controls. After the first year of bereavement, however, mortality rates of relatives of a deceased person did not differ significantly from the control group Rees and Lutkins (1967) [2]. Similar findings were published by Parkes et al. (1969) [3] following up on 4486 widowers at the age of 55 for 9years following the death of their wives in 1957. During the first six months after the spouse had died, the mortality rate of the widowers was 40% above the rate of married men of the same age. While it seems plausible to accept the etiological role and pathogenic impact of personal loss, the pathogenic processes causing death remained relatively blurred. We will explain, why inaccurately stressing the fact that the broken heart and/or tako-tsubo syndrome would be a relatively new way of looking at stress-related cardiomyopathy as outlined by Yoshikawa (2015) [4] and why attaching stress-related cardiomyopathy to culturally powerful yet value-laden metaphors, might obstruct pathways to a better understanding, prevention and clinical management of the disease. By looking at narrative understandings and clinical representations of the broken heart, we aim to highlight the need for a more contextualised view of the broken heart syndrome in order to facilitate multi- and transdisciplinary approaches aiming at its prediction, prevention, and treatment.

The natural history of takotsubo syndrome: a two-year follow-up study with myocardial sympathetic and perfusion G-SPECT imaging

PURPOSE

To investigate changes in sympathetic activity, perfusion, and left ventricular (LV) functionality in takotsubo cardiomyopathy (TTC) patients from onset (T₀) to post-onset conditions at 1 month (T₁), 1-2 years (T₂, T₃).

METHODS

Twenty-two patients (70 ± 11 years) underwent serial gated single photon emission tomography (G-SPECT) studies with ¹²³I-mIBG and ^99mTc-Sestamibi. Statistics were performed using ANOVA/Sheffé post-hoc, correlation test, and receiver operating characteristic (ROC) curve analysis (p < 0.05).

RESULTS

Patients presented at T₀ with LV ballooning and reduced early-late mIBG uptake (95%, 100%), left ventricular ejection fraction (LVEF)_G-SPECT (86%) and perfusion (77 %). Adrenergic dysfunction was greater in apex, it overlaps with contractile impairment, and both were more severe than perfusion defect. During follow-up, LVEF_G-SPECT, contractility, and perfusion were normal, while 82% and 90% of patients at T₁ and 50% at T₂ and T₃ continued to show a reduced apical early-late mIBG distribution. These patients presented at T₀-T₁ with greater impairment of adrenergic function, contractility, and perfusion. A relationship was present within innervation and both perfusion and contractile parameters at T₀ and T₁, and between the extent of adrenergic defect at T₃ and both the defect extent and age at T₀ (cut-off point 42.5%, 72 years).

CONCLUSION

Outcome for TTC is not limited to a reversible contractile and perfusion abnormalities, but it includes residual adrenergic dysfunction, depending on the level of adrenergic impairment and age of patients at onset. The number of patients, as well as degree of perfusion abnormalities were found to be higher than those previously reported possibly depending on the time-interval between hospital admission and perfusion scan.

Recurrent takotsubo with prolonged QT and torsade de pointes and left ventricular thrombus

Takotsubo cardiomyopathy, also known as “takotsubo syndrome,” refers to transient apical ballooning syndrome, stress cardiomyopathy, or broken heart syndrome and is a recently recognized syndrome typically characterized by transient and reversible left ventricular dysfunction that develops in the setting of acute severe emotional or physical stress. Increased catecholamine levels have been proposed to play a central role in the pathogenesis of the disease, although the specific pathophysiology of this condition remains to be fully determined. At present, there have been very few reports of recurrent takotsubo cardiomyopathy. In this case report, we present a patient with multiple recurrences of takotsubo syndrome triggered by severe emotional stress that presented with recurrent loss of consciousness, QT prolongation, and polymorphic ventricular tachycardia (torsade de pointes) and left ventricular apical thrombus.

Takotsubo cardiomyopathy systematic review: Pathophysiologic process, clinical presentation and diagnostic approach to Takotsubo cardiomyopathy

Takotsubo cardiomyopathy (TTC) is characterized by transient left ventricular apical ballooning with the absence of coronary occlusion, which typically occurs in older women after emotional or physical stress. The pathophysiology of TTC is not well established, though several possible causes such as catecholamine cardiotoxicity, metabolic disturbance, coronary microvascular impairment and multivessel epicardial coronary artery spasm have been proposed. A number of diagnostic criteria have been suggested in the world and not unified as single, but the most common accepted one is Mayo Clinic proposed criteria. Since the clinical presentation of TTC is usually similar to acute coronary syndrome, differential diagnosis is essential to exclude other diseases and also for its treatment. Imaging modality including echocardiogram, angio CT and cardiac MRI, and lab tests for catecholamine, troponin T, creatine kinase MB and B-type natriuretic peptide can be useful to differentiate TTC from other diseases. Prognosis is generally favorable and in-hospital mortality is from 0% to within 10%.

Role of Coronary Microvascular Dysfunction in Takotsubo Cardiomyopathy

Takotsubo cardiomyopathy (TTC) is a relatively frequent acute cardiac condition, but its pathogenesis has not been established as yet. Since the first descriptions of TTC, microvascular dysfunction has been advocated as a possible pathophysiological mechanism underlying the left ventricular wall motion abnormalities that characterize the syndrome. Several noninvasive and invasive methods have confirmed the involvement of coronary microvascular abnormalities in the pathogenesis of TTC, but whether microvascular dysfunction is the primary cause or a secondary phenomenon is still debated. The greater prevalence of TTC among postmenopausal women, along with the relationship identified between physical and emotional triggers and other "neuro-cardiac" mechanisms, suggest that increased microvascular reactivity, possibly sympathetically mediated, may play a pathogenic role in susceptible individuals. This review critically evaluates the possible role of microvascular dysfunction in the development of TTC.

Impact of Brain Natriuretic Peptide, Calcium Channel Blockers, and Body Mass Index on Recovery Time from Left Ventricular Systolic Dysfunction in Patients With Takotsubo Cardiomyopathy

Takotsubo cardiomyopathy (TC) is generally recognized to have a good prognosis, but it can be rarely aggravated. We sought to investigate the clinical characteristics of TC and to evaluate the effects of clinical parameters on predicting delayed recovery. We enrolled consecutive patients with TC admitted to our hospital from January 1991 to January 2014. We defined delayed recovery as sustained left ventricular (LV) systolic dysfunction requiring ≥10 days for LV contraction to normalize. We screened 9,630 patients suspected of having acute coronary syndrome, and 60 patients (0.6%; men/women: 20/38; mean age: 69.7 ± 11.9 years) were diagnosed as having TC. With the exception of 2 patients who died before LV systolic function improved, all patients recovered from LV systolic dysfunction within 6 months; the mean recovery period was 9.1 ± 11.5 days. Twenty-eight patients met the criteria for delayed recovery. Univariate logistic regression analyses showed that male gender, LV end-diastolic diameter, brain natriuretic peptide (BNP) level, body mass index (BMI), and nonuse of calcium channel blockers (CCBs) at baseline were associated with delayed recovery. Among these factors, multiple logistic regression analysis identified BNP ≥238 pg/ml (relative risk [RR] 11.6, p = 0.002) and nonuse of CCBs (RR 22.2, p = 0.0014) as independent risk factors for delayed recovery and leptosomic build (BMI <20 kg/m(2)) as an independent predictor of rapid recovery (RR 0.11, p = 0.02). In conclusion, BNP level, BMI, and use of CCBs are associated with recovery speed of LV systolic function in patients with TC.

Usefulness of myocardial positron emission tomography/nuclear imaging in Takotsubo cardiomyopathy

AIM: To analyse and summarize all the articles related to positron emission tomography and Takotsubo cardiomyopathy (TTC).

METHODS: We performed a systematic review of the existing literature on positron emission tomography/nuclear imaging and Takotsubo cardiomyopathy using PUBMED database. We combined search terms such as “takotsubo”, “takotsubo syndrome”, “myocardial positron emission tomography”, “positron emission tomography”. All case reports were excluded. The list included only four articles which were reviewed by two independent investigators. It was not possible to undertake a formal meta-analysis because of the heterogeneity of the studies; therefore, we made a narrative synthesis of the collected data.

RESULTS: Nuclear medicine techniques can be useful employed in the differential diagnosis of TTC from an acute coronary syndrome (ACS). In fact, transient left ventricular (LV) apical ballooning is a syndrome frequently misdiagnosed as an ACS and can mimic symptoms of myocardial infarction with ST-T segments changes on electrocardiography (ECG), a limited release of myocardial enzyme, mainly reported after sudden emotional or physical stress, and an akinesis or dyskinesis of the left ventricle apex which are completely reversible in a few weeks. In the studies included in this review, nuclear medicine techniques have demonstrated a discrepancy between normal perfusion and a reduced glucose utilization in TTC, commonly known as “inverse flow metabolism mismatch”. This suggests that apical ballooning represents a transient metabolic disorder on the cellular level, rather than a structural contractile disease of the myocardium, due to a transient decrease of glucose metabolism that might be related to a coronary microcirculation impairment followed by prolonged myocardial stunning.

CONCLUSION: Nuclear medicine techniques can be usefully used for the diagnosis of TTC and can increase our knowledge of the pathophysiological mechanisms of TTC.

Delayed multifocal recurrent stress-induced cardiomyopathy after antidepressants withdrawal

Stress-induced cardiomyopathy is an acute disease characterized by a large left ventricular apical dyskinesia ("apical ballooning"), triggered by intense emotional or physical stress, acute illnesses or, rarely, by alcohol or opiates withdrawal. Connection to stress and apical asynergy suggest a catecholamine-mediated pathogenesis. We recently observed a typical apical stress-induced cardiomyopathy, arising two weeks after a long-lasting antidepressant treatment withdrawal and recurring, a week later, with evidence of inferior wall akinesia. The reported case has several unusual features: 1) both episodes were not preceded by relevant triggering event (except antidepressant discontinuation); 2) early heterozonal relapse was observed; 3) the latency between antidepressant discontinuation and stress-induced cardiomyopathy onset is unusually long. The lack of relevant triggering stress and the evidence of multifocal asynergies could support the hypothesis of a non-catecholaminergic pathogenesis. Moreover, the long latency after antidepressant withdrawal may suggest that prolonged antidepressant treatments may have delayed pathological consequences, possibly related to their known neuroplastic effects.

Impaired coronary microvascular reactivity in women with apical ballooning syndrome (Takotsubo/stress cardiomyopathy)

AIMS

The pathophysiology of apical ballooning syndrome (ABS) remains to be elucidated. The aim of this study was to evaluate the coronary vascular reactivity of patients who were previously diagnosed with ABS.

METHODS AND RESULTS

A total of 228 cases of ABS were prospectively identified, and of these, 10 patients (median age 61 years (IQR 48-75); all females) who underwent coronary vasomotion testing were included in the study. Coronary epicardial and microvascular responses to intracoronary acetylcholine (ACH; % change in diameter and % change in blood flow at doses of 10(-6)-10(-4) mol/l), nitroglycerin (200-300 mg), and adenosine (36-60 µg) were evaluated. The median change in diameter with ACH was -9.3% (IQR -36.4, 3.2) with six patients (60%) demonstrating epicardial coronary constriction. The median increase in peak coronary blood flow in response to ACH was 13.1% (IQR -18.6, 55.0). This was markedly lower than the blood flow response seen in a reference group of 211 women from our laboratory (mean age 60 years) with normal microvascular responses to ACH: 103% (IQR 75, 149). Seven (70%) patients had <50% increase in coronary blood flow indicating abnormal microvascular response to ACH. 70% had either abnormal epicardial or microvascular response to ACH. Median coronary flow reserve was abnormal at 2.2% (IQR 2.0, 3.4; normal >2.5), and 90% had at least one abnormal measure of microvascular vasomotion.

CONCLUSION

The novel observation is that coronary microvascular dysfunction is highly prevalent in patients with ABS. Thus, chronically impaired coronary vascular reactivity, especially involving the microcirculation, may be a central feature of the pathophysiology of ABS.

Diagnostic utility of 123I-BMIPP imaging in patients with Takotsubo cardiomyopathy

OBJECTIVE

Takotsubo cardiomyopathy is a cardiac syndrome with an acute onset defined by chest symptoms and ST segment elevation on electrocardiograms. Takotsubo cardiomyopathy is sometimes misdiagnosed as acute myocardial infarction (AMI). Therefore a non-invasive diagnostic method is needed to be established for setting up appropriate strategies. The purpose of this study was to detect myocardial metabolic abnormalities and to determine the diagnostic usefulness of (123)I-beta-methy-iodophenyl pentadecanoic acid ((123)I-BMIPP) imaging in patients with takotsubo cardiomyopathy.

METHODS AND RESULTS

We examined 16 patients with takotsubo cardiomyopathy and 12 with AMI in the left anterior descending artery. All patients were studied with resting (123)I-BMIPP imaging. Total defect score (TDS) of (123)I-BMIPP and perfusion were semi-quantitatively determined with single-photon emission computed tomography (SPECT) imaging using a 17-segment 5-point model. TDS of (123)I-BMIPP were 4.8 ± 2.7 in patients with Takotsubo cardiomyopathy and 22.4 ± 10.7 in AMI. The ratio of summed BMIPP defect score of non-apical to apical segments in Takotsubo cardiomyopathy was smaller than that of the patients with AMI (0.1 ± 0.1 vs. 1.1 ± 0.7, p < 0.0001), indicating that (123)I-BMIPP abnormalities were exclusively observed the in apical area. The ratio of summed perfusion defect scores of non-apical to apical segments in takotsubo cardiomyopathy did not differ significantly from that of AMI (0.52 ± 0.6 vs. 0.57 ± 0.3, p = NS). Summed BMIPP defect score in the apical area of takotsubo cardiomyopathy was larger than that of perfusion defect score (3.9 ± 2.7 vs. 1.8 ± 1.8, p = 0.04).

CONCLUSION

Impaired metabolic metabolism exclusively in the apical region was observed by (123)I-BMIPP SPECT images in takotsubo cardiomyopathy. These typical metabolic SPECT features of the disease can be utilized on differential diagnosis of takotsubo cardiomyopathy.

A PET/CT-follow-up imaging study to differentiate takotsubo cardiomyopathy from acute myocardial infarction

Takotsubo cardiomyopathy (TTC) is still an under-recognized disease and little data exists on the coexistence of TTC and obstructive coronary artery disease. Our patient case of an 80-year-old female lady highlights the impact of a positron emission tomography/computed tomography (PET/CT) follow-up imaging study to delineate this unique entity from acute coronary syndrome (ACS). Furthermore, we show for the first time that coronary flow reserve and myocardial blood flow is globally impaired in TTC and not only restricted to the non-contracting parts. This indicates a global microcirculatory impairment effect of the heart in the acute stage of TTC. Our case also demonstrates that a transient metabolic defect is also involved in this disease. Follow-up imaging by PET/CT in our patient case unmasked TTC and facilitated to exclude the differential diagnosis of ACS.

LAD coronary artery myocardial bridging and apical ballooning syndrome

OBJECTIVES

This study sought to evaluate the prevalence and potential role of myocardial bridging in the pathogenesis of apical ballooning syndrome (ABS).

BACKGROUND

ABS is characterized by reversible left ventricular dysfunction, frequently precipitated by a stressful event, but the pathogenesis remains still unclear.

METHODS

Forty-two consecutive patients (40 female, mean age 66 ± 7 years) with ABS underwent echocardiography, cardiac magnetic resonance, coronary angiography (CA) with intravascular ultrasound, and computed tomography angiography (CTA). Myocardial bridging was diagnosed by CA when a dynamic compression phenomenon was observed in the coronary artery and by CTA when a segment of coronary artery was completely (full encasement) or incompletely (partial encasement) surrounded by the myocardium. The prevalence of myocardial bridging detected by CTA and CA in ABS patients was compared with 401 controls without ABS who underwent both CTA and CA.

RESULTS

Myocardial bridging by CTA was observed in 32 ABS patients (76%): 23 with partial encasement and 9 with full encasement. All myocardial bridging was located in the mid segment of the left anterior descending coronary artery (LAD) with a mean length of 17 ± 9 mm. CA revealed myocardial bridging in 17 subjects (40%) (9 with partial encasement and 8 with full encasement by CTA). All subjects in which dynamic compression was observed by CA showed myocardial bridging by CTA, while none of the subjects with negative findings for myocardial bridging by CTA revealed dynamic compression by CA. Compared with controls, ABS patients showed a significant higher prevalence of myocardial bridging in the LAD either by CA (40% vs. 8%; p < 0.001) or by CTA (76% vs. 31%; p < 0.001).

CONCLUSIONS

Our study showed that myocardial bridging of the LAD is a frequent finding in ABS patients as revealed both by CA and, mostly, by CTA, suggesting a role of myocardial bridging as potential substrate in the pathogenesis of ABS.

Scintigraphic imaging in Tako-Tsubo cardiomyopathy

Tako-Tsubo cardiomyopathy (TTC, stress cardiomyopathy) is more common in elderly women and its symptoms can be deceptively similar to those of acute myocardial infarction. Although coronary arteries appear normal on coronary angiograms, a shape like a Tako-Tsubo (a Japanese fishing pot for trapping octopuses) can be observed on left ventriculogram. TTC is generally considered to be a trigger for sudden cardiac death. The onset mechanism of TTC is still controversial. Catecholamine cardiotoxicity and/or coronary circulation disturbance due to coronary microvascular spasm and/or neurogenic stunned myocardium as a result of autonomic imbalance are considered to be the most likely causes. In this review, we assess the usefulness of myocardial scintigraphic imaging in TTC patients on the basis of the results obtained from earlier studies and case reports in order to establish a deeper understanding of the pathophysiological mechanism of this syndrome.

Stress cardiomyopathy: diagnosis, pathophysiology, management, and prognosis

Stress cardiomyopathy is now a well-recognized reversible cardiomyopathy, with a clinical presentation mimicking Acute Coronary syndrome in the absence of significant coronary artery disease. It is often encountered in postmenopausal females and is usually precipitated by acute emotional or physical stressors. In this review, we have attempted to summarize relevant data regarding diagnosis, typical and atypical presentations, pathophysiology, management options, and prognosis. Typically, patients present with chest pain and shortness of breath, transient electrocardiographic changes, moderate troponin elevation, and are found to have wall motion abnormalities (apical and midventricular akinesis with preserved basal segment systolic function) without obstructive coronary lesions, with complete resolution in next few weeks. The precise pathophysiology remains unclear, but excessive catecholamine stimulation, metabolic disturbances, and dysfunction of microcirculation are thought to be the underlying mechanisms.

Broken heart in elderly patients: two clinical observations

Tako-tsubo cardiomyopathy (idiopathic or transient left ventricular apical ballooning syndrome [ABS]) is a reversible condition frequently precipitated by a stressful trigger that clinically mimics an acute ST-elevation myocardial infarction. Characteristically, hypokinesis or akinesis occurs in the mid- and apical segments of the left ventricle in the absence of epicardial coronary lesions. Preserved or hyperdynamic function of the basal myocardial segments results in apical ballooning, assuming the shape of a Japanese pot used to catch octopus (a takotsubo). We report on 2 well over 70 years old women (78 and 82 years) admitted to the emergency room with chest pain. Clinical signs, ECG alterations and high troponin I in both patients imposed urgent diagnostic testing and management. The electrocardiographic findings were consistent with acute myocardial infarction and transthoracic echocardiography showed in both simultaneous apical akinesia and a hyperkinetic basal area with a moderately reduced left ventricular ejection fraction. Coronary angiography, performed on an emergency basis, in both cases revealed minimal luminal irregularities, with no evidence of plaque rupture or thrombus. The wall motion abnormality extended beyond the distribution of any single coronary artery, making it less likely that an occlusive thrombus had spontaneously dissolved or that intermittent vasospasm had occurred. Taken together, these findings were consistent with ABS, and critical observations on coronary angiography indicated the diagnosis by exclusion. The patients were seen in the clinic 4 weeks after discharge. They had had no recurrent chest pain, and had returned to the normal life they had had before the cardiovascular event. A repeat echocardiography showed a normalized estimated ejection fraction in both patients. ABS is a diagnosis of exclusion and its incidence is probably underestimated in elderly patients in whom coronary angiography is not common.

Coincidence of apical ballooning syndrome (tako-tsubo/stress cardiomyopathy) and posterior reversible encephalopathy syndrome: potential common substrate and pathophysiology?

BACKGROUND

Apical ballooning syndrome (ABS) and posterior reversible encephalopathy syndrome (PRES) are recently described, seemingly unrelated, reversible conditions. The precise pathophysiology of these syndromes remains unknown. The aim of this study was to describe the clinical characteristics and outcomes of a unique series of patients with both ABS and PRES.

METHODS AND RESULTS

In a retrospective study of 224 consecutive patients diagnosed with ABS between 2002 and 2010, 6 (2.7%) were also diagnosed with PRES. All were female with a mean age of 63.7 ± 12.5 years. All patients had preceding medical comorbidities and physical stress triggers that precipitated ABS and PRES. Mean peak troponin T levels and left ventricular ejection fraction at presentation were 0.47 ± 0.48 mg/dL and 31.5 ± 8.2%, respectively. Characteristic left ventricular wall motion abnormalities (regional wall motion score index 2.22 ± 0.37) were noted in all patients, and magnetic resonance imaging of the brain was significant for vasogenic edema, predominantly in the posterior circulation. All patients recovered left ventricular (ejection fraction at follow-up 60.2 ± 6.0%) and neurologic function with supportive management. Two patients had recurrence of ABS and 1 of PRES during follow-up.

CONCLUSIONS

ABS and PRES can occur simultaneously during an acute illness. Patients with ABS who develop neurologic dysfunction should be evaluated for PRES and vice versa. Because transient sympathetic overactivity and microvascular dysfunction have been observed in both reversible syndromes, we speculate that they may represent the shared pathophysiologic mechanism.

Takotsubo cardiomyopathy--a clinical review

Stress cardiomyopathy is characterised by reversible left ventricular dysfunction. It simulates an acute coronary syndrome (ACS), presenting with precordial pain or dyspnoea, changes of the ST segment, T wave, or QTc interval on electrocardiogram, and raised cardiac enzymes. Typical findings are disturbances of segmental contractility (apical hypokinesia or akinesia), with normal epicardial coronary arteries. The true prevalence is unknown, as the syndrome may be under-diagnosed; it is more common in postmenopausal women. There is usually a trigger in the form of physical or psychological stress. The electrocardiographic, echocardiographic, and ventriculographic changes resolve spontaneously over a variable period of time (from days to months). There are a number of pathophysiological theories, none of which has been shown to be definitive, suggesting that all of them may be involved to some extent. The prognosis is generally favourable, and recurrence is very rare.

Serum lipoprotein levels in takotsubo cardiomyopathy vs. myocardial infarction

Background

In the setting of myocardial infarction (MI) or acute coronary syndrome (ACS), current guidelines recommend early and aggressive lipid lowering therapy with statins, irrespective of the baseline lipoprotein levels. Takotsubo cardiomyopathy (TCM) patients have a clinical presentation similar to myocardial infarction and thus receive early and aggressive statin therapy during their initial hospitalization. However, the pathology of TCM is not atherosclerotic coronary artery disease and hence we assumed the lipid profiles in TCM would be healthier than coronary artery disease patients.

Methods

In this retrospective study, we assessed fasting serum lipoprotein levels of ten TCM patients and compared them with forty, age and sex-matched myocardial infarction (MI) patients.

Results

Comparing serum lipoprotein levels of TCM with MI group, there was no significant difference in mean total cholesterol between the two groups (174.5 mg/dL vs. 197.6 mg/dL, p = 0.12). However, in the TCM group, mean HDL-C was significantly higher (66.87 mg/dL vs. 36.5 mg/dL, p = 0.008), the mean LDL-C was significantly lower (89.7 mg/dL vs. 128.9 mg/dL, p = 0.0002), and mean triglycerides was also significantly lower (65.2 mg/dL vs. 166.8 mg/dL, p < 0.0001).

Conclusions

In this study, TCM patients in comparison to MI patients had significantly higher levels of HDL-C, lower levels of LDL-C levels and triglycerides. The lipid profiles in TCM were consistent with the underlying pathology of non-atherosclerotic, non-obstructive coronary artery disease. As lipoproteins in most TCM patients were within the optimal range, we recommend an individual assessment of lipid profiles along with their coronary heart disease risk factors for considering long term lipid-lowering therapy. A finding of hyperalphalipoproteinemia or hypotriglyceridemia in 40% of TCM patients is novel but this association needs to be confirmed in future studies with larger sample sizes. These findings may provide clues in understanding the pathogenesis of takotsubo cardiomyopathy.

Takotsubo Cardiomyopathy: A Cardiac Syndrome Mimicking Acute Myocardial Infarction in a Liver Transplant Recipient

Takotsubo cardiomyopathy (TTC) is a rare clinical syndrome defined as a profound but reversible left ventricular dysfunction in the absence of coronary artery disease. We describe the clinical features and management of TC manifesting in the postoperative period in a patient undergoing liver transplantation. Two days after surgery, the patient developed clinical features of acute myocardial infarction. Ecochardiography revealed hypokinesis of the left ventricle. Coronary angiography revealed normal arteries without any stenosis or obstruction. The patient required vasopressor and inotropic support. The placement of intra-aortic balloon pump had a beneficial effect on the management of heart failure. The patient had a complete recovery of cardiac function 40 days after surgery. TC is a possible occurrence after liver transplant. Awareness of this condition is essential as early diagnosis and prompt management can save the patient’s life.

Endothelial function and vascular response to mental stress are impaired in patients with apical ballooning syndrome

OBJECTIVES

The aim of the current study was to test the hypothesis that vascular and endothelial functional responses to acute mental stress are abnormal in patients with apical ballooning syndrome (ABS).

BACKGROUND

Apical ballooning syndrome is a transient cardiomyopathy that occurs predominantly in post-menopausal women and may be triggered by acute mental stress. The mechanism for ABS is unknown.

METHODS

Reactive hyperemia as a parameter of endothelial function and vascular responses to acute mental stress were measured using peripheral arterial tonometry (PAT) at baseline and following 3 acute mental stress tests in female patients with ABS (n = 12, at least 6 months after being hospitalized or diagnosed with ABS), post-menopausal female controls (n = 12), and female patients with myocardial infarction (MI) (n = 4). Plasma catecholamine levels were measured at baseline and following the 3 mental stress tests.

RESULTS

Reactive hyperemia PAT scores following mental stress were significantly lower in patients with ABS compared with post-menopausal controls (p < 0.05). The PAT scores during mental stress were significantly lower in patients with ABS compared with patients with MI and post-menopausal controls (p < 0.05). There were no differences in PAT scores during acute mental stress in patients with MI versus post-menopausal controls. Furthermore, catecholamine levels were significantly increased in patients with ABS, compared with post-menopausal controls, following acute mental stress testing (p < 0.05).

CONCLUSIONS

There is increased vascular reactivity and decreased endothelial function in response to acute mental stress in patients with a prior episode of ABS. The findings implicate vasomotor dysfunction as a potential mechanism involved in the pathogenesis of this unique cardiomyopathy.

Anxiety trait in patients with stress-induced cardiomyopathy: a case-control study

BACKGROUND

Stress-induced Tako-tsubo cardiomyopathy (TTC) is an acute cardiac syndrome, mimics ST elevation myocardial infarction (STEMI), largely confined to postmenopausal women, frequently precipitated by a stressful event. The pathogenesis of TTC is still unknown. Some authors hypothesized a possible connection between TTC and anxiety disease, but no previous study analyzed the relationship between anxiety trait and TTC. This study sought to assess the potential role of anxiety trait in the development and clinical course of TTC.

METHODS

We included in the present prospective case-control study 50 consecutive patients admitted to our Hospital with a diagnosis of TTC according to the Mayo Clinic criteria. Fifty control patients with anterior STEMI matched for clinical characteristics such as age, gender, and hypertension were selected. During the hospitalization, all patients were asked to complete the Spielberger Trait Anxiety Inventory (STAI) scale for measuring self-reported trait anxiety (Trait-A). Outcome measures at follow-up were death, TTC recurrence, and rehospitalization.

RESULTS

The mean value of STAI scale was 46 ± 12 in TTC patients and 45 ± 14 in STEMI patients (p = 0.815). High-anxiety trait (STAI scale value ≥ 40) was documented in 30 (60%) TTC patients and in 26 (52%) STEMI patients (p = 0.387). At multivariate analysis, predictors of TTC were lower peak creatine kinase value (HR 0.999; 95% CI 0.998-0.999; p = 0.018) and an antecedent stressful trigger event (HR 45.487; 95% CI 6.471-319.759; p = 0.001), but anxiety trait was not. There were no differences in outcome measures between TTC patients with or without high-anxiety trait.

CONCLUSION

In TTC patients, high-anxiety trait is a common finding but it is not significantly more frequent than in patients with STEMI. Moreover, a high-anxiety trait seems to be neither associated with a worse clinical outcome nor a predictor of TTC. Our study do not support the routine evaluation of anxiety trait in patients with TTC.

Takotsubo cardiomyopathy is not due to plaque rupture: an intravascular ultrasound study

BACKGROUND

Plaque rupture with subsequent transient thrombotic coronary occlusion by a fast-dissolving clot is one of the proposed pathogenic mechanisms in Takotsubo cardiomyopathy (TC).

HYPOTHESIS

The aim of this study was to seek evidence for the hypothesis of transient coronary thrombosis as the underlying mechanism of TC by means of intravascular ultrasound (IVUS).

METHODS

In our database of 63 consecutive patients with TC we identified 10 patients (16%) who had undergone IVUS during their initial left heart catheterisation.

RESULTS

A median length of 67 mm of the left anterior descending artery was analyzed (interquartile range [IQR]: 63.3-70.1 mm). Median lumen diameter, median vessel diameter, median plaque and media volume were 2.9 mm (IQR: 2.7-3.1 mm), 4.2 mm (IQR: 3.8-4.4 mm), and 90.9 mm(3) (IQR: 70.4-101.4 mm(3)), respectively. Plaque rupture, positive remodeling, and presumed intracoronary thrombus were absent in all patients.

CONCLUSION

In conclusion, plaque rupture does not account for the regional wall motion abnormalities observed in TC. The previously reported observation of plaque rupture in TC seems to constitute an incidental finding. We suggest that the theory of aborted myocardial infarction as the underlying cause of TC should be abandoned once and for all.

Stress cardiomyopathy

Recently, an increasing number of cases of stress cardiomyopathy, mainly occurring in elderly women, have been documented in many parts of the world. In Japan, this disease is known as takotsubo cardiomyopathy (named after the fishing pot used for trapping octopus). Symptoms of this condition are akin to those of acute myocardial infarction, but no obstructive lesions are found in the coronary arteries, and left ventricular apical ballooning is present. Stress cardiomyopathy is now a well-recognized cause of acute heart failure, lethal ventricular arrhythmias, and ventricular rupture. Although the precise mechanism of onset of this condition is still controversial, two major pathogenic mechanisms have been proposed: catecholamine cardiotoxicity and neurogenic stunned myocardium. We summarize the findings of studies conducted to date on stress cardiomyopathy-from bench to bedside and bedside to bench.

Role of the excessive amounts of circulating catecholamines and glucocorticoids in stress-induced heart disease

Various stressful stimuli are known to activate the sympathetic nervous system to release catecholamines and the hypothalamic-pituitary-adrenal axis to release glucocorticoids in the circulation. Although initial actions of both catecholamines and glucocorticoids are beneficial for the function of the cardiovascular system, their delayed effects on the heart are deleterious. Glucocorticoids not only increase plasma levels of catecholamines by inhibiting their extraneuronal uptake, but they have also been shown to induce supersensitivity to catecholamines in the heart by upregulating different components of the betta-adrenoceptor signal transduction system. Low concentrations of catecholamines stimulate the heart by promoting Ca2+ movements, whereas excessive amounts of catecholamines produce cardiac dysfunction by inducing intracellular Ca2+ overload in cardiomyocytes. Several studies have shown, however, that under stressful conditions high concentrations of catecholamines become oxidized to form aminolutins and generate oxyradicals. These oxidation products of catecholamines have been demonstrated to produce coronary spasm, arrhythmias, and cardiac dysfunction by inducing Ca2+-handling abnormalities in both sarcolemmal and sarcoplasmic reticulum, defects in energy production by mitochondria, and myocardial cell damage. In this article we have focused the discussion to highlight the interrelationship between catecholamines and glucocorticoids and to emphasize the role of oxidation products of catecholamines in the development of stress-induced heart disease.

Stress cardiomyopathy syndrome: a contemporary review

Stress cardiomyopathy (SC) syndrome represents a reversible form of cardiomyopathy that commonly presents proximate to an acute emotional or physiologic stressor. The clinical presentation is similar to an acute coronary syndrome in the absence of obstructive coronary artery disease to explain the unusual distribution of associated transient wall motion abnormalities. Postmenopausal women seem particularly prone to SC for unclear reasons. The pathophysiology of the syndrome is unknown but may involve pathologic sympathetic myocardial stimulation.